Green Analytical Chemistry

Current advances in microalgae-based fucoxanthin production and downstream processes

Fucoxanthin, a marine carotenoid primarily found in brown algae and microalgae, offers significant health benefits, including antioxidant, anti-obesity, and anti-cancer effects. While brown algae remain the dominant commercial source, microalgae such as Phaeodactylum tricornutum are emerging as promising candidates for large-scale, sustainable fucoxanthin production. This review explores advancements in fucoxanthin biosynthesis, focusing on cultivation methods, extraction techniques, and genetic engineering strategies. Different cultivation systems - including autotrophic, heterotrophic, and mixotrophic approaches - have been assessed for their biomass yield, cost-effectiveness, and scalability, together with a quantitative meta-analysis to highlight specific trends or correlations in fucoxanthin production. The efficiency and environmental impact of extraction methods, such as supercritical fluid extraction, ultrasound-assisted extraction, and microwave-assisted extraction, have also been evaluated. In addition, synthetic biology and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based genetic modifications show potential for enhancing fucoxanthin biosynthesis. However, challenges remain in terms of cost, scalability, and regulatory constraints. This review highlights the need for integrated biotechnological solutions to enhance commercial viability, combining metabolic engineering, efficient extraction techniques, and optimized cultivation strategies. As demand continues to grow in the nutraceutical, pharmaceutical, and cosmetic industries, ongoing advancements in microalgae-based fucoxanthin production will be critical for ensuring sustainable and cost-effective manufacturing.

Green extraction of bioactive flavonoids in Scutellariae Radix using deep eutectic solvents-based ultrasound-assisted matrix solid phase dispersion combined with computer-aided analysis

An efficient and sustainable deep eutectic solvents-based ultrasound-assisted matrix solid phase dispersion (DES-UAMSPD) method was proposed for extracting the bioactive flavonoids in Scutellariae Radix (SR), with molecular sieve (ZSM-5) as dispersant and betaine-levulinic acid (Bet-Lea (1:2, 50 % water content)) as the effective extractant. The interaction mechanism of DES formation and extraction process was comprehensively elucidated by computer simulation techniques such as electrostatic potential (ESP) distributions, independent gradient model based on hirshfeld partition (IGMH) and frontier molecular orbitals theory. The response surface methodology experiments were conducted to optimize the extraction conditions. Under optimal extraction conditions, the total content of five analytes (baicalin, oroxyloside, wogonoside, baicalein and wogonin) reached 182.66 mg g-1, which was 1.50-2.19 folds higher than conventional extraction solvents. The greenness and environmental friendliness of the proposed method were evaluated through Green Analytical Procedure Index and Analytical Eco-Scale. Additionally, this quantitative method exhibited reliable linearity for the analytes (r2 > 0.9997) and excellent recovery (95.4 %-102 %, RSD < 2.72 %). The limits of detection ranged from 0.02 to 0.04 μg mL-1. Overall, these results highlighted the excellent extraction and quantification capability of the proposed approach, which offered an environmentally friendly strategy for effective extraction of bioactive compounds from natural products.

Green analytical approaches for contaminants: Sustainable alternatives to conventional chromatographic methods

The growing importance of environmental sustainability has driven advancements in analytical chemistry, particularly in the development of green chromatographic techniques. This review explores various chromatographic methods that align with green chemistry principles, offering environmentally friendly alternatives to traditional gold-standard approaches. Techniques such as supercritical fluid chromatography (SFC), miniaturized liquid chromatography (LC), and gas chromatography (GC) with alternative carrier gases (e.g., hydrogen and nitrogen) are discussed in depth for their ability to reduce solvent consumption, minimize waste, and improve operational efficiency. These methods not only maintain high sensitivity and accuracy but also reduce the ecological impact of contaminant analysis. By comparing these sustainable approaches to conventional techniques, this review highlights their potential to meet regulatory standards while supporting eco-friendly practices within routine analysis laboratories.

Multivariate analysis of potentially toxic metal contents in soil and vegetables: Enrichment, bioconcentration, translocation from soil to vegetables, and assessment of human health toxicity

The excessive accumulation of metals in agricultural soils can profoundly impact the quality of vegetables grown in contaminated soil. Understanding the bioaccumulation of these metals in vegetables is essential for assessing human exposure risks. The present study aimed to investigate the concentration of potentially toxic metals (PTMs: Fe, Mn, Cu, Zn, Al, As, Cr, Cd, and Pb) in agricultural soil and some commonly consumed vegetables (carrot, reddish, cauliflower, pumpkin, and spinach). The samples were collected from agrarian farmlands near the industrial area of Multan Road, Kasur-Pakistan. The mean contents of all metals in soil, root, and shoot samples were within the limits set by the EU, WHO, FAO, and US EPA, except for Cr in soil and Cr, Cd, and Pb in root samples. Across all analyzed vegetables, the bioconcentration factors (BCFroot and BCFshoot < 1, except As) and translocation factor (TF < 1) for all metals suggested that while these vegetables absorb metals, they generally do not accumulate or translocate them. Multivariate analysis indicated that both natural and anthropogenic activities contribute to metal contamination. The calculated hazard index (HI > 1) and cumulative cancer risk (CCR >1 × 10-3) values indicated the probability of non-carcinogenic and carcinogenic health risks for adults and children associated with the consumption of these vegetables. The findings provide critical insights for policymakers, agricultural regulators, and public health authorities to mitigate metal contamination risks and promote food safety.

A sensitive HPLC method with fluorescence detection for quantification of pemigatinib in human plasma samples and its in-vivo application to pharmacokinetic study in rats

Cholangiocarcinoma is a lethal tumour of the bile ducts. Cholangiocarcinoma fibroblast growth factor receptor gene fusions forms can be targeted by Pemigatinib (PGT). PGT a recently approved kinase inhibitor by the US-FDA, has its approval accelerated due to the disease viciousness. Development of a sensitive yet available and economical analytical platform to quantify PGT in human plasma is genuinely needed. Enabling monitoring of the therapeutic plan, hence, ensuring the drug efficacy and safety through pharmacokinetic studies. High-performance liquid chromatography with fluorescence detector (HPLC-FD) method is proposed using the native fluorescence of PGT. PGT and seliciclib (internal standard) chromatographic conditions optimisation, revealed favourable use of isocratic mobile phase consisting of methanol:ammonium acetate buffer (70:30v/v, pH5.0) pumped into C18-column (150 mm length × 4.6 mm internal diameter, 5 μm particle size), at 1 mL min-1 flow rate. PGT and seliciclib fluorescence excitation and emission were measured at 280 and 360 nm, respectively. Validation of the HPLC-FD method was processed based on the International Council for Harmonization guidelines. The method linearity range was 5-300 ng mL-1. The limits of detection and quantification were 2.8 and 8.5 ng mL-1, respectively. High precision and accuracy indicated by relative standard deviation ≤ 5.2, and recovery values of 95.4-102.2 %. Evident of the method greenness was verified by green analytical chemistry metric tools. HPLC-FD method was successfully applied to study PGT pharmacokinetics in rats. In conclusion, this study introduces a reliable analytical method of PGT in plasma for routine use in therapeutic drug monitoring for quality assurance and clinical follow-up.

Distance-based quantitation of urinary ammonia using a low-cost cellulose-based thread sensor impregnated with curcumin

Effective point-of-care (POC) methods for detecting metabolic disorders, such as hyperammonemia, are crucial. Urinary ammonia is an underexplored but physiologically relevant biomarker for such conditions and can be conveniently monitored noninvasively. Conventional detection methods, while reliable, are time-consuming and costly. We propose a green, low-cost microfluidic distance-based thread analytical device (dTAD) that incorporates curcumin for urinary ammonia quantification. Through a simple immersion technique, curcumin was deposited on the surface of cellulose-based threads, resulting in a user-friendly device that correlates ammonia titers to a naked-eye colorimetric distance-based measurement. Curcumin undergoes a color change from yellow to red in the presence of ammonia and demonstrates strong selectivity with major interferants in urine. Moreover, this sensor exhibits a linear range of 20.0-80.0 mmol L-1 (R2 = 0.994) with a limit of detection (LOD) of 5.0 mmol L-1. The LOD was theoretically predicted using the mass balance volatilization of ammonia along the thread channel in conjunction with Darcy's law. The thread-based device offers significant advantages in terms of simplicity, affordability, versatility, and future scalability. With a total analysis time of 3.0 min, a cost of less than $0.20 per sensor, and a recovery range of 91%-102% in human control urine samples, the device meets the demands of REASSURED (Real-time connectivity, Ease of specimen collection, Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, and Deliverable) POC diagnostics for the developing world. To the best of our knowledge, this is the first application of a distance-based thread device that quantifies ammonia in biofluid samples.

Micellar media effect on the ultrasensitive quantitation of a diuretic medication at nano-scale levels with environmentally benign impact

A novel micelle-augmented spectrofluorimetric method is proposed for the ultrasensitive estimation of bumetanide (BUM) at nanoscale concentrations. The method utilizes the unique properties of micelles to enhance the fluorescence intensity of BUM and measures its native fluorescence at 415 nm after excitation at 267 nm. The proposed method was optimized by evaluating the effect of organized media, buffer pH, and diluting solvent. The method validity was further assessed following the ICH guidelines, where excellent linearity was obtained over a concentration range of 40.0-400.0 ng mL-1, with a correlation coefficient of 0.9999 and a low limit of detection (LOD) of 5.31 ng mL-1. The method was further applied for the determination of BUM in different dosage forms with % recoveries greater than 98%, as well as for content uniformity testing. Ultimately, a comprehensive assessment of the method's environmental impact was performed using different metrics, highlighting the eco-friendly nature of the method and underlining its potential for sustainable analytical practices in pharmaceutical research and beyond.

Lab-in-syringe automated dispersive solid-phase microextraction of alkylphenols coupled online to liquid chromatography using iron (III) thenoyltrifluoroacetonate as dissolvable sorbent

BACKGROUND

Alkylphenols are water contaminants of strong endocrine disruptive potential. Sample preparation is generally imperative to improve sensitivity and minimize matrix effects. Dispersive solid phase extraction is a powerful alternative to cartridge-based sorbent extraction omitting backpressure problems and reducing procedural time. Herein, solvent-dissolvable sorbents offer the advantages of easy and cost-efficient production, efficiency, and full analyte recovery, while eluates can be directly submitted to instrumental determination. Despite the potential to reduce environmental impact and enhance reproducibility, there is a lack of automation attempts.

RESULTS

A fully automated solvent-assisted dispersive solid phase extraction method was developed for selected alkylphenols based on the technique Lab-In-Syringe. The void of automatic bidirectional syringe pump was used as mixing and extraction vessel. The iron(III) thenoyltrifluoroacetonate complex was used as novel dissolvable sorbent. 40 μL complex solution was dispersed in the sample, leading to the precipitation of 0.4 mg sorbent. Extraction occurred within 40 s and was accelerated by in-syringe magnetic stirring. The sorbent was retained on a melamine foam packing in the syringe inlet, dissolved in a methanolic solution of ascorbic acid, and injected into online-coupled HPLC. Linear working ranges were achieved from 1 to 1000 μg/L with sub-ppb detection limits and accuracies ranging from 98.3 to 110 %.

SIGNIFICANCE

In this work, we explored for the first time automated in-syringe automated dispersive SPE based on a dissolvable sorbent. Parallel operation of sample pretreatment and separation enabled throughputs of 4.5/h with typically <5 % RSD and preconcentrations of 16.4-21.2. AGREE greenness evaluation yielded a score of 0.59.

Exploring Green Practices: a Review of Carbon Dot-Based Sustainable Sensing Approaches

The increasing demand for sustainable and eco-friendly technologies has driven significant interest in carbon dots (CDs) due to their unique optical properties, low toxicity, and versatile applications in sensing. The aim of this review is to provide a comprehensive analysis of the current advancements in CD-based sensing approaches, with a focus on their environmental sustainability based on greenness evaluation tools. We begin by discussing the principles and methodologies of greenness evaluation, including various assessment tools and metrics used to measure the environmental impact of CD synthesis and applications. Key applications of CD-based sensors in detecting pollutants, biomolecules, and other analytes are examined, emphasizing their potential in environmental monitoring, biological, and food analysis. The review concludes with a discussion on future research directions aimed at overcoming these challenges and enhancing the sustainability of CD-based sensing technologies. Through this detailed exploration, we aim to provide valuable insights into the greenness of CDs, fostering their development as a cornerstone of sustainable sensing technologies. The evaluation tools applied for future probes confirmed their superior environmental friendliness.

Integrating green analytical chemistry and analytical quality by design: an innovative approach for RP-UPLC method development of ensifentrine in bulk and inhalation formulations

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a significant global health issue, worsened by pollution and modernisation. Ensifentrine (EFT), a new dual inhibitor of phosphodiesterase PDE3 and PDE4, is being developed for inhalation to target airway inflammation, bronchodilation, and ciliary function in COPD treatment.

OBJECTIVE

This study aims to develop and validate a new quantification method for Ensifentrine, as no previous techniques are available, by integrating analytical quality-by-design (AQbD) and green analytical chemistry (GAC) principles.

METHODS

An AQbD framework, utilizing Design-expert® software and a central composite design, optimized the RP-UPLC method. The optimized conditions involved isocratic separation on an ACQUITY UPLC HSS C18 SB column at ambient temperature, with a mobile phase of 0.01 N KH2PO4 (pH 5.4) and acetonitrile (66.4:33.6 v/v), a flow rate of 0.27 mL/min, and PDA detection at 272.0 nm.

RESULTS

The statistical analysis confirmed the model's significance and normal distribution. The method, validated according to ICH guidelines, showed good linearity (r2 = 0.9997) over a range of 3.75-22.5 μg/mL, with an LOD of 3.3 μg/mL and LOQ of 10 μg/mL. It was successfully applied to bulk materials and pharmaceutical formulations with statistical comparisons.

GREEN CHEMISTRY ASSESSMENT

The greenness of the developed method was evaluated using tools such as ComplexMoGAPI, AGREE, BAGI, Green certificate-modified Eco-scale, and ChlorTox Scale. Additionally, the EVG method evaluation tool was also used to assess environmental impact, with the results shown in a radar chart.

CONCLUSION

This study presents a sensitive and robust RP-UPLC method for quantifying Ensifentrine, combining AQbD and GAC principles. The method, validated according to ICH guidelines, also ensures environmental sustainability. This approach sets a precedent for future analytical method development in pharmaceutical sciences with a focus on sustainability.

Monitoring of the Biotechnological Production of Dihydroxyacetone Using a Low-Field 1H NMR Spectrometer

The concept of sustainable production necessitates the utilization of waste and by-products as raw materials, the implementation of biotechnological processes, and the introduction of automated real-time monitoring for efficient use of resources. One example is the biocatalyzed conversion of the reusable by-product glycerin by acetic acid bacteria to dihydroxyacetone (DHA), which is of great importance to the cosmetic industry. The application of compact spectrometers enables the rapid measurement of samples while simultaneously reducing the consumption of resources and energy. Yet, this approach requires comprehensive data preprocessing and, on occasion, multivariate data analysis. For the process monitoring of the production of DHA, a low-field 1H nuclear magnetic resonance (NMR) spectrometer was implemented in on-line mode. Small-volume samples were taken from a bypass and transferred to the spectrometer by an autosampler. Complete analysis within minutes allowed real-time process control. To this purpose, reliable automated spectral preprocessing preceded the creation of a univariate model. The model enabled the acquisition of process knowledge from chemical kinetics and facilitated the tracking of both substrate and product concentrations, requiring independent calibration. As a second multivariate approach, principal component analysis was utilized to monitor the process in a semi-quantitative manner without the necessity for calibration. The results of this study are beneficial for real-time monitoring applications with the objective of exerting control over the process in question while minimizing expenditure.

Label-Free Spectrofluorometric Method for Simultaneous Estimation of Methocarbamol and Aspirin in Biological and Pharmaceutical Matrices: Whiteness and Greenness Evaluation

A combination of methocarbamol and aspirin is commonly used for the treatment of acute musculoskeletal pain, such as low back and neck pain. Simultaneous analysis of these analytes in dosage forms and biofluids using rapid, sensitive, and selective methods would be highly beneficial. Herein, we report the first direct, label-free spectrofluorometric method for simultaneously quantifying methocarbamol (MET) and aspirin (ASP) in coformulated tablets and spiked human urine. The method utilizes excitation at 274 nm with independent emission detection at 300 nm for MET and 402 nm for ASP, using methanol as the diluting solvent. The assay was rectilinear over ranges of 0.10-0.80 μg/mL for MET and 0.05-0.50 μg/mL for ASP with detection limits of 14.9 and 10.6 ng/mL for MET and ASP, respectively. The method was validated in compliance with ICH regulations. The approach was applied efficiently to assay both analytes in their tablets and spiked human urine with high % recoveries (98%-103%) and low RSD (1.7%-3.3%). In addition, the sustainability and practicality of the developed method were assessed using the RGB-12 whiteness algorithm, indicating the whiteness of the developed method. The method's greenness was also confirmed using three greenness metrics that showed excellent eco-friendliness of the developed method.

Green quantification of amino(poly)phosphonates using ion chromatography coupled to integrated pulsed amperometric detection

Aminopolyphosphonates (APPs) are widely used as chelating agents, and their increasing release into the environment has raised concerns due to their transformation into aminomethylphosphonic acid (AMPA) and glyphosate, compounds of controversial environmental impact. This transformation highlights the urgent need for detailed studies under controlled conditions. Despite the availability of various methods for quantifying individual aminopolyphosphonates and aminomonophosphonates, a green, low-cost approach for the simultaneous quantification of APPs and their transformation products in laboratory experiments has been lacking. In this study, we present a novel analytical method utilizing ion chromatography (IC) coupled to integrated pulsed amperometric detection (IPAD) to simultaneously quantify the six aminophosphonates: AMPA, glyphosate, iminodi(methylene phosphonate) (IDMP), aminotrismethylene(phosphonates) (ATMP), ethylenediamine tetra(methylene phosphonate) (EDTMP), and diethylenetriamine penta(methylene phosphonate) (DTPMP). This method achieves separation within a 35-min run time and method detection limits (MDLs) ranging from 0.014 μM for AMPA to 0.14 μM for DTPMP. The method's applicability was successfully shown by monitoring DTPMP, IDMP, and AMPA during DTPMP transformation on manganese dioxide. A key advantage of this method is its environmental friendliness compared to existing aminophosphonate quantification techniques. Next to the simultaneous analysis, it avoids the use of derivatization agents and organic solvents and employs an energy-efficient detector. While the method's limitations lie in the detector's inherent non-specific nature, it offers a low-cost and sustainable alternative to existing methods.

Green Microextraction, Paper-Based Technique, and Smartphone Sensing for Sustainable Determination of Nicotinamide in Pharmaceuticals and Blood Samples

This study presents the development of two simple, sensitive, and selective microextraction and preconcentration procedures for determining nicotinamide (NAM) in pharmaceutical formulations and blood samples. The methods utilize the König reaction, where cyanogen chloride, formed by reacting potassium thiocyanate with sodium hypochlorite in an acidic medium, interacts with NAM and couples with buffered barbituric acid at pH 3.5 to form a pink polymethine dye. This dye is extracted into an isobutanol layer using tetrabutylammonium bromide and exhibits maximum absorption at 560 nm for spectrophotometric quantification. In the smartphone paper-based (SPB) method, the dye is applied to a paper strip, captured by a smartphone, and analyzed for red, green, and blue components. Both methods were thoroughly evaluated for key parameters, demonstrating adherence to Beer's law over a NAM concentration range of 1.0-7.8 µg/mL, with limits of detection of 0.76 µg/mL for the spectrophotometric method and 0.91 µg/mL for the SPB method. Our SPB combines paper-based analysis, smartphone detection, and microextraction for the first time, offering a cost-effective, portable, and sensitive solution for NAM assay in plasma. A comparison with the established high-performance liquid chromatography method, using statistical tests, showed no significant differences, confirming the reliability of these novel methods.

Ecofriendly colorimetric set-up coupled with mathematical filtration strategy for simultaneous determination of ipratropium and fenoterol in their novel anti-asthmatic metered dose inhaler

Ipratropium bromide (IPR) and fenoterol hydrobromide (FEN) are well-known medications for treating asthma and chronic obstructive pulmonary disease (COPD). A simple, feasible, efficient, and cost-effective colorimetric assay has been established for determination of the newly introduced co-formulated metered dose inhaler (Atrovent® comp HFA). The developed method is based on the properly optimized reaction of drugs under study with the charge transfer reagent 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), resulting in orange-colored complexes measured at 464.3 and 514.0 nm for IPR and FEN, respectively. Smoothly applicable and easily manipulated resolution method, Vierordt's method, based on straightforward mathematical equations that do not need complicated software was implemented for the simultaneous determination of IPR and FEN. The proposed methodology can be applied in routine analysis enabling fast and economical determination of the combined dosage form without the need for previous separation steps. The validity of the proposed colorimetric method was thoroughly assured as per ICH guidelines with acceptable accuracy and precision. The linearity ranges for IPR and FEN were 5.0-55.0 µg/mL and 10.0-40.0 µg/mL, respectively. Using cutting-edge software metric tools, namely the analytical greenness (AGREE), and complementary green analytical procedure index (ComplexGAPI), the greenness profile of the suggested method was clearly evaluated. The method also conformed well to the recently published blueness (BAGI tool) and whiteness (RGB12 tool) concepts.

Green extraction using natural deep eutectic solvents for determination of As, Cd, and Pb in plant and food matrices by ICP-MS

In this study, extraction methods using natural deep eutectic solvents (NADES) were proposed for the determination of arsenic (As), cadmium (Cd), and lead (Pb) in plant and food matrices. NADES are green and sustainable solvents with advantageous chemical properties for such applications. The NADES were prepared with different components, characterized, and applied in ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) methods. Experimental variables including temperature, extraction time, and sample-solvent ratio, were investigated using experimental designs to establish the optimal extraction conditions before analysis by ICP-MS. For the MAE method, the optimal conditions were extraction temperature of 100 °C, extraction time of 40 min, and SSR of 40:1 m v-1, resulting in recoveries of up to 84 %. For the UAE method, the optimal conditions were 40 °C, 40 min, and sample-solvent ratio (SSR) of 30:1 m v-1, with recoveries ranging from 96 % to 109 %, all with relative standard deviations less than 11 %. The proposed methods provided low detection limits (mg kg-1), with values of <0.0160 for As, <0.0030 for Cd, and < 0.0090 for Pb for UAE and MAE. The methods were considered green, achieving scores of 0.54 (MAE) and 0.45 (UAE) on the analytical greenness metric for sample preparation. The use of NADES as efficient extractants, combined with multivariate optimization, resulted in optimal experimental conditions, good analytical performance, and enhanced sustainability. The proposed method is a promising approach for applications in food safety and public health studies.

Electrochemical study of anti-platelets tirofiban HCl in dosage form using nanomaterials modified sensors: developed and green assessed by eco-scale and complex-GAPI approach

Tirofiban hydrochloride is used to inhibit platelet aggregation, which has a significant impact on the treatment of congestive heart failure the most common cause of death according to WHO. Therefore, its quantification in pharmaceutical dosage form is critical. In this work, an electrochemical method for the determination of tirofiban HCl in pharmaceutical dosage form was developed and validated. Carbon paste electrode modified with multi-walled carbon nanotubes (MWCNT) was utilized to examine the electrochemical response of tirofiban hydrochloride. Scanning electron microscopy and Energy-dispersive X-ray analysis was used to investigate the morphology of this electrode. A linear response was obtained within the range of (27.00-745.00 ng/mL) (5.4 × 10-5 M-1.5 × 10-3 M) with a correlation coefficient of 0.9995, and a detection limit of 15.50 ng/mL (3.1 × 10-5 M). The greenness profile of the method was assessed utilizing the eco-scale and the green analytical procedure Index.

A quality by design HPLC method for cephalosporin analysis in pharmaceuticals and water samples with environmental impact assessment

The present study applied a combined analytical quality-by-design and green analytical chemistry approach to develop an HPLC method for the determination of four cephalosporin pharmaceuticals in both their formulations and water samples. These drugs include ceftriaxone, cefotaxime, ceftazidime and cefoperazone. A Box-Behnken experimental design was employed to optimize three chromatographic parameters: mobile phase composition, flow rate and buffer pH. The predicted optimal conditions involved using a mobile phase of acetonitrile and 0.04 M phosphate buffer at pH 6 in a 7:93 (v/v) ratio, pumped at 1.3 mL/min through a Nucleosil C18 (4.6 × 250 mm, 5 μm) column with UV detection at 240 nm. Under these optimum conditions, the developed HPLC method successfully separated the four drugs with good resolution in less than 6 min. Linearity was established across the concentration ranges of 5-300 µg/mL for ceftriaxone and cefotaxime, 5-400 µg/mL for ceftazidime and 5-100 µg/mL for cefoperazone. Furthermore, full validation of the method in terms of accuracy, precision, specificity and robustness was carried out as per ICH guidelines. The greenness profile of the optimized HPLC method was also evaluated using the Analytical GREEnness (AGREE) tool and found to be environmentally friendly with AGREE score of 0.75, making it a greener alternative for quality control and routine analysis of the investigated cephalosporins in their pharmaceutical formulations and tap water samples. Furthermore, the blueness assessment of the proposed HPLC method using the blue applicability grade index (BAGI) tool yielded a value of 77.5, indicating its high analytical practicality and substantial potential for routine analysis applications.

Rapid and Environment-Friendly LC-MS/MS for Simultaneous Analysis of Amino Acids in Veterinary Medicine

BACKGROUND

Amino acid supplements are crucial for animal health and productivity. Traditional analysis methods face limitations like complexity, long testing times and toxic reagents. Therefore, a more efficient and reliable method is needed.

OBJECTIVES

This study aimed to develop and validate an efficient method for the simultaneous analysis of eight amino acids commonly used in veterinary medicine: alanine, arginine, glutathione, lysine, ornithine, methionine, threonine and tryptophan.

METHODS

We analysed eight veterinary amino acid preparations. From 100 registered products, we selected 35. After confirming ingredients, we diluted them to 1 mg/L with 50% acetonitrile (ACN) and filtered them using a 0.2 µm RC filter for liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis.

RESULTS

All analytes showed excellent linearity (r2 > 0.99) within 0-10 mg/L. The limits of detection (LOD) ranged from 0.04 to 0.83 mg/L, and the limits of quantification (LOQ) ranged from 0.12 to 2.52 mg/L. Average recovery ranged from 92.96% to 105.61%, with relative standard deviations (RSD) from 0.27% to 3.50%, meeting CD 2002/657/EC standards. Six out of the 35 products (17.14%) did not meet regulations.

CONCLUSIONS

The method developed in this study offers an efficient and reliable approach for the simultaneous analysis of essential amino acids in veterinary medicine. Implementing this method can improve the quality control of amino acid products, enhancing animal health and productivity. This study also highlights the need for stringent domestic management and continuous monitoring. By overcoming traditional technique limitations, this validated method ensures the quality and efficacy of amino acid supplements in the veterinary industry.

Comparison of the Performance of ICP-MS, CV-ICP-OES, and TDA AAS in Determining Mercury in Marine Sediment Samples

Mercury (Hg) determination in marine sediment is an analytical challenge due to the toxicity of this element even at low concentrations (up to 130 μg kg-1 in marine sediments) and complex matrices. Therefore, it is necessary to use analytical techniques that have high sensitivity, selectivity, and low limits of quantification (LoQ). In this study, two methods that require sample treatment and one method with direct sampling were studied. The techniques studied were inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectrometry with cold vapor generation (CV-ICP-OES), and atomic absorption spectrometry with thermodecomposition and amalgamation (TDA AAS) for Hg determination in marine sediment samples. Since ICP-MS has more studies in the literature, optimization with design of experiments was developed for CV-ICP-OES and TDA AAS. Although it was found to have low levels of instrumental LoQ for all three techniques, differences were found once the method LoQ was calculated. The calculation for method LoQ considers all analytical procedures executed, including sample treatment, which provides a 100-fold dilution for ICP-MS and CV-ICP-OES. The method LoQ obtained were 1.9, 165, and 0.35 μg kg-1 for ICP-MS, CV-ICP-OES, and TDA AAS, respectively. Comparing marine sediment sample analyses, Hg concentrations had no statistical difference when determined by ICP-MS and TDA AAS. It was not possible to determine Hg in marine sediment samples by CV-ICP-OES due to the high method LoQ obtained (165 μg kg-1). Although ICP-MS has the advantage of being a multielemental technique, it is high-value equipment and needs a large volume of argon, which has a high cost in the market, and it requires sample treatment. On the other hand, TDA AAS-based spectrometer DMA-80 performs direct sampling, avoiding the pretreatment stage, and has a relatively lower cost, both in terms of initial investment and maintenance, while maintaining the high sensitivity, accuracy, and precision required for Hg determination on marine sediment samples.

A green chemical analysis of ethanol using a smart phone

This research presents a novel method for measuring ethanol concentrations using a smartphone. The method involves an oxidation reaction with potassium dichromate and concentrated sulfuric acid, resulting in a green-blue color formation. The color intensity, corresponding to ethanol concentrations ranging from 0 to 100%, was captured using a smartphone camera within a specialized photography box. The images were then analyzed using a specific application, converting the color signal into an absorbance value. The calibration curve demonstrated excellent linearity in the range of 0-0.55 v/v % and its detection limit is 0.01 v/v%, with a correlation coefficient exceeding 0.995. The method was successfully applied to measure ethanol in real samples, including ordinary rose water and a bitter wheat drink.•The method is inexpensive.•The method is rapid.•The method is green.

Green analytical chemistry metrics for evaluating the greenness of analytical procedures

Green analytical chemistry (GAC) focuses on mitigating the adverse effects of analytical activities on human safety, human health, and environment. In addition to the 12 principles of GAC, proper GAC tools should be developed and employed to assess the greenness of different analytical assays. The 15 widely used GAC metrics, i.e., national environmental methods index (NEMI), advanced NEMI, assessment of green profile (AGP), chloroform-oriented toxicity estimation scale (ChlorTox Scale), Analytical Eco-Scale, Green Certificate Modified Eco-Scale, analytical method greenness score (AMGS), green analytical procedure index (GAPI), ComplexGAPI, red-green-blue (RGB) additive color model, RGB 12 algorithm, analytical greenness calculator (AGREE), AGREE preparation (AGREEprep), HEXAGON, and blue applicability grade index (BAGI), are selected as the typical tools. This article comprehensively presents and elucidates the principles, characteristics, merits, and demerits of 15 widely used GAC tools. This review is helpful for researchers to use the current GAC metrics to assess the environmental sustainability of analytical assays.

Sustainable approaches to analyzing phenolic compounds: a green chemistry perspective

Innovative and eco-friendly methodologies for the determination of phenolic compounds, showing a paradigm shift in analytical chemistry toward sustainability. Phenolic compounds, valued for their diverse health benefits, have historically been analyzed using methods that often involve hazardous solvents and energy-intensive processes. This review focuses on green analytical chemistry principles, emphasizing sustainability, reduced environmental impact, and analytical efficiency. The use of DES, specifically Ch: Chl-based DES, emerges as a prominent green alternative for extracting phenolic compounds from various sources. The integration of UAE with DES enhances extraction efficiency, contributing to a more sustainable analytical approach. Furthermore, the review highlights the significance of DLLME and SPME in reducing solvent consumption and simplifying extraction procedures. These techniques exemplify the commitment to making phenolic compound analysis environmentally friendly. The incorporation of portable measurement tools, such as smartphones, into analytical methodologies is a notable aspect discussed in the review. Techniques like UA-DLLME leverage portable devices, making phenolic compound determination more accessible and versatile. Anticipating the future, the review foresees ongoing advancements in sustainable analytical approaches, driven by collaborative efforts across diverse disciplines. Novel solvents, extraction techniques, and portable measurement methods are expected to play pivotal roles in the continuous evolution of green analytical methodologies for the analysis of phenolic compounds. The review encapsulates a transformative journey toward environmentally responsible and efficient analytical practices, paving the way for further research and application in diverse analytical settings.

Facilitating inorganic arsenic speciation and quantification in waters: Polymer inclusion membrane preconcentration and X-ray fluorescence detection

BACKGROUND

Arsenic, classified as a priority pollutant and human carcinogen by the IARC, is subject to stringent regulatory limits in food and water. Among various arsenic species found in water samples, arsenite (As(III)) is identified as the most toxic form. Given the limitations of conventional spectroscopic techniques in speciation analysis, there is a crucial need for innovative and sustainable methodologies that enable arsenic speciation. Simplifying these methodologies is essential for widespread applicability and effective environmental monitoring.

RESULTS

This study proposes a simple and cost-effective analytical methodology for speciating inorganic arsenic in water samples. The method involves extracting As(III) into a polymer inclusion membrane (PIM) containing the extractant Cyanex 301 (bis(2,4,4-trimethylpentyl) dithiophosphinic acid), followed by analysis using energy dispersive X-ray fluorescence (EDXRF) spectrometry. The concentration of arsenate was measured after a reduction step using a thiosulfate/iodide mixture. This simple methodology allows a limit of quantification for trivalent arsenic (2 μg L-1), which is well below the World Health Organization's recommended maximum permissible level of As in drinking water (10 μg L-1). The method that is developed allows the determination of As at trace levels in waters with naturally occurring arsenic.

SIGNIFICANCE AND NOVELTY

This study represents a significant advance in the field, providing a novel and efficient methodology for arsenic speciation analysis in water samples. By combining the advantages of polymer inclusion membrane (PIM) extraction with energy dispersive X-ray fluorescence (EDXRF) spectrometry, this study offers a cost-effective and environmentally friendly approach to address the critical issue of arsenic contamination in water sources, thereby contributing to enhanced environmental monitoring and public health protection.

Greening Separation and Purification of Proteins and Peptides

The increasing awareness of environmental issues and the transition to green analytical chemistry (GAC) have gained popularity among academia and industry in recent years. One of the principles of GAC is the reduction and replacement of toxic solvents with more sustainable and environmentally friendly ones. This review gives an overview of the advances in applying green solvents as an alternative to the traditional organic solvents for peptide and protein purification and analysis by liquid chromatography (LC) and capillary electrophoresis (CE) methods. The feasibility of using greener LC and CE methods is demonstrated through several application examples; however, there is still plenty of room for new developments to fully realize their potential and to address existing challenges. Thanks to the tunable properties of designer solvents, such as ionic liquids and deep eutectic solvents, and almost infinite possible mixtures of components for their production, it is possible that some new designer solvents could potentially surpass the traditional harmful solvents in the future. Therefore, future research should focus mainly on developing new solvent combinations and enhancing analytical instruments to be able to effectively work with green solvents.

IR-EcoSpectra: Exploring sustainable ex situ and in situ FTIR applications for green chemical and pharmaceutical analysis

In various industries, particularly in the chemical and pharmaceutical fields, Fourier transform infrared spectroscopy (FTIR) spectroscopy provides a unique capacity to detect and characterise complex chemicals while minimising environmental damage by minimal waste generation and reducing the need for extensive sample preparation or use of harmful reagents. This review showcases the versatility of ex situ and in situ FTIR applications for substance identification, analysis, and dynamic monitoring. Ex situ FTIR spectroscopy's accuracy in identifying impurities, monitoring crystallisation processes, and regulating medication release patterns improves product quality, safety, and efficacy. Furthermore, its quantification capabilities enable more effective drug development, dosage procedures, and quality control practices, all of which are consistent with green analytical principles. On the other hand, in situ FTIR spectroscopy appears to be a novel tool for the real-time investigation of molecular changes during reactions and processes, allowing for the monitoring of drug release kinetics, crystallisation dynamics, and surface contacts, as well as providing vital insights into material behaviour. The combination of ex situ FTIR precision and in situ FTIR dynamic capabilities gives a comprehensive analytical framework for developing green practices, quality control, and innovation in the chemical and pharmaceutical industries. This review presents the wide range of applications of ex situ and in situ FTIR spectroscopy in chemical, pharmaceutical and medical fields as an analytical green chemistry tool. However, further study is required to fully realise FTIR's potential and develop new applications that improve sustainability in these areas.

Evaluation of analytical greenness metric for an eco-friendly method developed through the integration of green chemistry and quality-by-design for the simultaneous determination of Nebivolol hydrochloride, Telmisartan, Valsartan, and Amlodipine besylate

In recent years, the field of analytical chemistry has witnessed a notable shift towards the adoption of greener chromatographic methods, aiming to minimize the environmental impact. An effective strategy involves substituting conventional harmful organic solvents with environmentally friendly alternatives, reducing the use of hazardous chemicals that contribute to environmental concerns. However, separating drug substances without the use of buffers and organic solvents presence is a big challenge. To overcome this challenge, a combination of quality-by-design (QbD) and green analytical chemistry (GAC) was employed in this study for method development. A high-performance liquid chromatography (HPLC) method was successfully developed and validated for the simultaneous determination of Nebivolol hydrochloride, Telmisartan, Valsartan, and Amlodipine besylate. The method utilized a mobile phase composed of a mixture of 0.1 % formic acid in water (pH: 2.5) and ethanol. A regular octadecyl silica (ODS) column was employed, and UV detection at 220 nm was utilized. The method exhibited linearity within the concentration range of 25-75 μg/mL for Telmisartan and 150-450 μg/mL for Nebivolol Hydrochloride, Valsartan, and Amlodipine besylate and the correlation coefficient was greater than 0.999 for all the analytes. Limits of detection (LOD) and quantification (LOQ) were determined as 0.01 and 0.04 μg/mL for Telmisartan, 0.06 and 0.20 μg/mL for Nebivolol Hydrochloride, 0.08 and 0.25 μg/mL for Amlodipine besylate, and 0.14 and 0.46 μg/mL for Valsartan, respectively. The developed method underwent thorough validation, encompassing various parameters such as linearity, accuracy, precision, LOD, LOQ, robustness, and ruggedness. The mean recovery values were observed to range between 98.86 % and 99.89 %. The accuracy demonstrated was consistently above 98.98 % for both intra-day and inter-day precisions were with the relative standard deviations less than 2 %. To establish its robustness, a quality-by-design-based experimental design (DoE) approach was implemented. Additionally, the method's environmental friendliness was evaluated using the Analytical Greenness metric (AGREE) an analytical eco scale, both confirming its alignment with sustainable practices and reduced ecological impact. The sustainability of the solvent used in the current study was evaluated by Green Solvents Selecting Tool (GSST) Further, the developed method greenness was evaluated with the green analytical tools such as Analytical method greenness score (AMGS) and using the recently released White Analytical Chemistry (WAC) using RGB assessment tool. By employing this greener approach to chromatography method, this study contributes to the ongoing efforts in analytical chemistry to promote sustainable practices and minimize the environmental footprint of analytical methods.

Greener and whiter analytical method development and validation for determining the presence of zolpidem tartrate infused in apple juice using RP-HPLC via magnetic solid-phase extraction followed by LC-MS confirmatory analysis

The research work entails a newly developed RP-HPLC method, aimed at analyzing the modern date rape drug, zolpidem tartrate (ZT), infused in apple juice matrix. The work relies on dispersive solid-phase extraction (DSPE) with polyethylene imine (PEI)-coated magnetic nanoparticles to preconcentrate zolpidem from the matrix, in the presence of trifluoroacetic acid (TFA) for matrix isolation, for the first time. The optimized conditions emphasize the use of an environmentally preferable mobile phase [methanol: 0.5% acetic acid (60 : 40% v/v; pH 2.50)] at a 1 ml min-1 flow rate, employed with a Platisil Octa-Decyl Silane (ODS) column (250 × 4.6 mm; 5 μm). Further, the validated results were confirmed to be within the ICH guidelines, marking the method demonstrated to be linear (R 2 = 0.9988; 0.9957), robust (% RSD below 1), sensitive (LOD = 1.8 μg ml; LOQ = 6 μg ml-1), precise and accurate (% recovery = 92-120%). Following the same conditions, a confirmatory analysis of zolpidem was accomplished using LC-MS, verifying the method's suitability notably, with good peak resolution, less matrix interference and a confirmation of the presence of zolpidem using mass spectrometry. The recycling ability of the PEI@SiO2@Fe3O4 nanoparticles was also assessed. To determine the sustainability of the proposed work, a greener and whiter assessment has been carried out in a comparative mode with previous similar works. For green tools, the recently developed AGREE software was utilized for assessing the method's greeness and it demonstrated a good green score of 0.68, supported by method assessment using ComplexGAPI software. For the assessment of the method's blue principles, the latest software utilizing the blue applicability grade index (BAGI) was applied, resulting in a decent score of 62.5. To consider sustainability, the RGB methodical software in its latest version the RGBfast model, was incorporated in the study for furnishing a balance of the three different major principles (Red-Green-Blue) and for assessing a check on sustainability of the current method compared to similar previously established proposed works.

Recent advances in solid phase microextraction with various geometries in environmental analysis

Solid phase microextraction (SPME) has emerged as a versatile sample preparation technique for the preconcentration of a broad range of compounds with various polarities, especially in environmental studies. SPME has demonstrated its eco-friendly credentials, significantly reducing the reliance on solvents. The use of biocompatible materials as a coating recipe facilitates the acceptance of SPME devices in analytical chemistry, primarily in the monitoring of environmental pollutants such as persistent organic pollutants (POPs), volatile organic compounds (VOCs), and pesticides from the various environmental matrices. During the last few years, investigators have reported an improvement in the SPME enrichment technique after changing the coating recipe, geometries, and sampling procedure from the complex matrices. Furthermore, the development of various geometries of SPME with large surface areas has enhanced the extraction efficiency of environmental pollutants. As a miniaturized sample preparation technique, SPME significantly reduces the solvent usage, suggesting a potential platform for green chemistry-based research for water, air, and soil analysis. This review article summarizes the evolution of SPME, its various modes, the application of SPME, recent innovations, and prospects for the determination of water, air, and soil pollution. The advantages and disadvantages of SPME in comparison to other extraction techniques have been discussed here. This review serves as a valuable resource for investigators working in sustainable environmental research.

Chromatographic fingerprinting of ipratropium and fenoterol in their novel co-formulated inhaler treating major respiratory disorders; application to delivered dose uniformity testing along with greenness and whiteness assessment

Ipratropium bromide (IPR) and fenoterol hydrobromide (FEN) have recently been combined in a promising inhaler to treat two prevalent inflammatory illnesses of the airways: bronchial asthma and chronic obstructive pulmonary disease (COPD). The necessity for a single, sensitive, and trustworthy analytical approach to cover the diverse and necessary tests of in-vitro and in-vivo studies is greatly grown with the rising production of new fixed combinations. Two novel, selective and environmentally friendly LC techniques were developed in order to guarantee precise measurement of IPR and FEN in their challenging formulation. The initial technique involved high-performance thin-layer chromatography (HPTLC) in conjunction with densitometric quantification. Chromatographic separation was attained on HPTLC plates utilizing ethyl acetate - ethanol - acetic acid (5.0:5.0:0.1, by volume) as a developing system. Densitometric quantification of the separated bands was carried out at 220.0 nm over concentration ranges of 0.50-15.0 µg/band for IPR and 0.50-12.0 µg/band for FEN. High-performance liquid chromatography (HPLC) paired with diode array detection (DAD) was the core of the second technique. The optimized separation was achieved on a Zorbax SB C18 (150 × 4.6 mm, 5 μm) column with a combination of 10.0 mM potassium dihydrogen orthophosphate, pH 5.0 ± 0.1, adjusted with o-phosphoric acid and methanol (70:30, v/v) as the mobile phase and pumped at flow rate of 1.0 mL/min. The peaks were monitored at 220.0 nm using diode array detection, achieving linearity range of 5.0-200.0 µg/mL for both drugs. The ICH criteria have been verified and both methods have been confirmed to be valid, and successfully applied for assay the cited drugs in the Atrovent® comp HFA metered dose inhaler as well as delivered dose uniformity testing of the final product. Finally, whiteness appraisal and several state-of-the-art green evaluation metrics were applied to evaluate the sustainability of the proposed methods. The suggested approaches produced promising results and are the first simple and sustainable methodologies for the simultaneous quantification of both drugs in different real samples, all of which strongly suggest their application in quality control laboratories.

Evaluating the effectiveness of different household washing techniques for removal of insecticides from spinach and chickpea leaves by micellar liquid chromatography

In the past few decades, the employment of green analytical approaches in chromatographic method development has attracted the analytical separation community. The greenness of the developed method depends upon the toxicity of solvents and the amount of generated post-analysis waste generated. In this concern, micellar liquid chromatography (MLC) is a simple and rapid technique that generates very low toxic waste compared to traditional chromatographic pesticide detection methods. Here, MLC method has been validated and applied for the determination of monocrotofos (MCF), imidacloprid (ICP), dimethoate (DM) and profenofos (PFF) in spinach and chickpea leaves. The optimized mobile phase was 0.065 M SDS-2 % 1-propanol, 0.01 M NaH2PO4 buffered to pH 7. A C18 column was used for separation with a flow rate of 1 mL/min. The developed method has been validated following the guidelines of SANTE/11,312/2021 and ICH guidelines for; limit of quantification (0.05-0.20 mg/kg), linearity (r2> 0.997-0.999), precision (<6.3 %), accuracy (96.3 %-99.8 %) and robustness (<6) in real samples. ICP and MCF, apart from DM and PFF, were detected in the present work. After detecting insecticides in spinach and chickpea leaves both were washed with different household chemicals i.e. normal, lukewarm, common salt, lemon juice water and commercial ozonizer. Based on five washing techniques with insecticide concentration time intervals reduction rates were calculated for each washing treatment. The results show that lemon juice, common salt water, and ozonizer can be used as washing techniques for the reduction of superficial and systematic residues of ICP and MCF. Common salt and lemon juice water were better for washing over vinegar and potassium permanganate (KMnO4) as they enhance the colour of the green leafy vegetables and are available in every Indian kitchen. They can be easily used by lower socioeconomic classes who cannot afford KMnO4 and vinegar.

Automated H2O2 monitoring during photo-Fenton processes using an Arduino self-assembled automatic system

A cheap and easy to use Arduino self-assembled automatic system was employed to continuously monitor the hydrogen peroxide consumption during the photo-Fenton degradation of caffeine, selected as model target compound. The automatic system made it possible to measure the H2O2 concentration in the reaction cell via a colorimetric reaction and to take samples for HPLC analysis minimising the operator manual intervention and exposure to UV radiation. The obtained results were compared in terms of LOD and LOQ with H2O2 measurements manually performed using UV-Vis spectrophotometry, evidencing better analytical performance when using the automatic system; LOD and LOQ were respectively 0.032 mM and 0.106 mM for the automatic system against 0.064 mM and 0.213 mM for UV-Vis spectrophotometry. Furthermore, the photo-Fenton treatment was optimised by means of a Design of Experiments (DoE) investigating the effect of added H2O2 concentration, iron concentration and caffeine initial concentration on system performances. The use of the automatic device for such monitoring provided several advantages: automation (with consequent reduction of the workload), measurement increased precision, reduced reagents consumption and waste production in agreement with the principles of Green Analytical Chemistry.

High Performance Thin Layer Chromatography (HPTLC) Analysis of Anti-Asthmatic Combination Therapy in Pharmaceutical Formulation: Assessment of the Method's Greenness and Blueness

A cost-effective, selective, sensitive, and operational TLC-densitometric approach has been adapted for the concurrent assay of Hydroxyzine Hydrochloride (HYX), Ephedrine Hydrochloride (EPH), and Theophylline (THP) in their pure powder and pharmaceutical forms. In the innovative TLC-densitometric approach, HYX, EPH, and THP were efficaciously separated and quantified on a 60F254 silica gel stationary phase with chloroform-ammonium acetate buffer (9.5:0.5, v/v) adjusted to pH 6.5 using ammonia solution as a mobile liquid system and UV detection at 220 nm. The novel TLC method validation has been performed in line with the international conference for harmonization (ICH) standards and has been effectively used for the estimation of the researched medicines in their pharmaceutical formulations without intervention from excipients. Additionally, parameters affecting the chromatographic analysis have been investigated. The new TLC approach's functionality and greenness were appraised using three modern and automated tools, namely the Blue Applicability Grade Index (BAGI), the Analytical Greenness metric (AGREE), and the Green Analytical Procedure Index (GAPI) tools. In short, the greenness characteristics were not achieved as a result of using mandatory, non-ecofriendly solvents such as ammonia and chloroform. On the contrary, the applicability and usefulness of the novel TLC approach were attained via concurrent estimation for the three drugs using simple and straightforward procedures. Moreover, the novel TLC method outperforms previously published HPLC ones in terms of the short run time per sample and moderate pH value for the liquid system. According to the conclusions of comparisons with previously recorded TLC methods, our novel HPTLC method has the highest AGREE score, so it is the greenest HPTLC strategy. Moreover, its functionality and applicability are very appropriate because of the simultaneous assessment of three drugs in one TLC run. Furthermore, no tedious and complicated extraction and evaporation processes are prerequisites.

A green, fluorescent probe employing erythrosine-B for tracing the accidental administration of levamisole in milk and plasma samples

A simple and sensitive fluorescent probe has been developed and optimized to detect the non-intentional administration of levamisole (LVM). LVM is used as an anthelmintic therapy in cows, and hence, its residues appear in the drained milk until 60 hours after administering the drug. Meanwhile, levamisole is known to be an adulterant to cocaine and could be detected in addicts' plasma samples. Owing to its severe side effects, including agranulocytosis, which is lethal in many cases, detection and quantification of LVM in milk and plasma samples are of utmost importance. Therefore, a sensitive and selective analytical method is required for this purpose. This work develops a highly fluorescent probe obtained through the reaction between LVM and erythrosine-B in an acidic medium, where the produced ion pair complex has been measured at 553 nm after excitation at 528 nm. The proposed method provides linearity over the concentration range of 0.5-2.0 μg mL-1 for LVM, with a corresponding detection and quantitation limit of 0.5 and 0.3 μg mL-1. Full validation was performed, permitting the application of the suggested method to perform simple extraction steps. All the applied procedures followed the guidelines offered by green analytical chemistry, where the Green Analytical Procedure Index (GAPI) assessed the greenness of the proposed tool, and the yielded pictograms proved the eco-friendliness of the offered tool.

Insights into the sustainability of liquid chromatographic methods for favipiravir bioanalysis: a comparative study

The introduction of favipiravir as a broad-spectrum antiviral agent, particularly in treating influenza and exploring its potential against COVID-19, emphasizes the necessity for efficient analytical methods. Liquid chromatography has emerged as a commonly utilized technique for quantifying favipiravir in biological fluids. However, the environmental and health concerns linked to classical analytical methods mean a transition toward green analytical chemistry is required. This study investigates the environmental impact of 19 liquid chromatographic methods utilized in the bioanalysis of favipiravir. Recognizing the importance of eco-friendly practices in pharmaceutical analysis, the study employs three widely accepted greenness assessment tools: Analytical Eco-Scale (AES), Green Analytical Procedure Index (GAPI), and Analytical Greenness Calculator (AGREE). Moreover, it incorporates a comprehensive evaluation on a global scale utilizing the whiteness assessment tool Red-Green-Blue 12 (RGB 12). The comprehensive evaluation aims to extend beyond traditional validation criteria and considerations of green chemistry, providing insights into the development of practically efficient, eco-friendly and economical analytical methods for favipiravir determination. This study emphasizes the necessity of planning for the environmental impact and overall sustainability of analytical methods before laboratory trials. Additionally, the integration of greenness/whiteness evaluation in method validation protocols is strongly advocated, emphasizing the importance of critical and global evaluations in analytical chemistry.

Biochar-based polymeric film as sustainable and efficient sorptive phase for preconcentration of steroid hormones in environmental waters and wastewaters

BACKGROUND

The environmental impact of sample preparation should be minimized through simplification of the procedures and the use of natural, renewable and/or reusable materials. In such scenario, thin-film microextraction fulfils the former criteria, as it enables few steps and miniaturization, thus small amount of extraction phase. At the same time, the use of sorbents such as biochars obtained from biomass waste is even more promoted due to their availability at low cost and increased life-cycle in a circular economy vision. However, it is not always easy to combine these criteria in sample preparation.

RESULTS

A thin film microextraction was developed for the determination of steroids in aqueous samples, entailing a membrane made of cellulose triacetate and a wood-derived biochar (Nuchar®) as carbon precursor. Different characterization techniques showed the successful preparation, whereas the sorption kinetics experiments demonstrated that biochar is responsible for the extraction with the polymer acting as a smart support. After a study about membranes' composition in terms of biochar amounts (4 %, 10 %, 16 % wt) and type of synthesis set up, the ceramic 3D-mold was selected, achieving reproducible and ready-to-use membranes with composition fixed as 10 %. Different elution conditions, viz. type and time of agitation, type, composition and volume of eluent, were evaluated. The final microextraction followed by HPLC-MS/MS quantification was successfully validated in river and wastewater treatment plant effluent samples in terms of accuracy (R% 64-123 %, RSD<19 % in river; R% 61-118 %, RSD <18 % in effluent, n = 4), sensitivity (MQLs 0.2-8.5 ng L-1) and robustness.

SIGNIFICANCE

This novel biochar-based polymeric film proved to be a valid and sustainable sorbent, in terms of extraction capability, ease of preparation and greenness. By comparison with literature and the greenness evaluation with the most recent metric tools, this method expands the potential applicability of the thin-film microextraction and opens up innovative scenarios for sustainable procedures entailing the use of biochars entrapped in bio-polymers.

Determination of trace chelating carboxylic acids in rice by green extraction combined with liquid chromatography-mass spectrometry analysis and its application in the evaluation of old and new rice

RATIONALE

Accurate identification of old rice samples from new ones benefits their market circulation and consumers. However, the current detection methods are still not satisfactory because of their insufficient accuracy or (and) time-consuming process.

METHODS

Chelating carboxylic acids (CCAs) were selectively extracted from rice, by stirring with chelating resin and a dilute Na2CO3 solution. The green analytical chemistry guidelines for sample preparation were investigated by using the green chemistry calculator AGREE prep. The extractant was determined by liquid chromatography-mass spectrometry (LC/MS), and statistical analysis of the analytical data was carried out to evaluate the significance of the difference by ChiPlot.

RESULTS

The limit of quantitation for the CCAs is in the range of 1 to 50 ng/mL, with a reasonable reproducibility. The CCAs in 23 rice samples were determined within a wide concentration range from 0.03 to 1174 μg/g. Intriguingly, the content of citric acid, malonic acid, α-ketoglutaric acid and cis-aconite acid in new rice was each found to be distinctively higher than that in old rice by several times. Even mixtures of old and new rice were found to show much difference in the concentration of citric acid and malic acid.

CONCLUSION

A green analytical method has been developed for the simultaneous determination of CCAs by LC/MS analysis, and the identification of old rice samples from new ones was easily carried out according to their CCA content for the first time. The results indicated that the described method has powerful potential for the accurate identification of old rice samples from new ones.

An Eco-Friendly RP-HPLC Method Development and Validation for Quantification of Favipiravir in Bulk and Tablet Dosage Form Followed by Forced Degradation Study

In this work, an eco-friendly simple, precise reverse phase high-performance liquid chromatography (HPLC) method has been developed and validated for Favipiravir in bulk and tablet dosage form followed by its force degradation study. The proposed method was validated to obtain official requirements including stability, accuracy, precision, linearity, robustness and selectivity as per International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Guidelines. The estimation was developed on C (18) column reversed-phase using the mobile phase composition as methanol:water (10:90 v/v). The flow rate was set as 1 ml/min, and the maximum absorption was observed at 323 nm using Shimadzu Photo Diode Array detector. The Favipiravir, drug showed a precise and good linearity at the concentration ranges of 10-50 μg/mL. The Revearse Phase High Perforance Liquid Chromatography assay showed the highest purity ranging from 99.90 to 100.02% for Favipiravir, tablet dosage form, and 100.15% was the mean percentage purity. The percent recovery was found within the acceptance limit of (98.6-100.0%). Intra- and inter-day precision studies of the method were less than the maximum allowable limit percentage of relative standard deviation ≤ 2.0. The Favipiravir retention time was found to be 5.00 min. To examine the stability of the drug, various forced degradation studies were conducted on Favipiravir Active Pharmaceutical Ingredient. The developed method was validated according to the ICH guidelines. A very quick, cost-effective, precise and accurate HPLC method for the determination of Favipiravir has been developed and validated in compliance with ICH guidance Q2.

A non-extraction sequential injection method for determination of loratadine using formation of its ion-association complex with bromocresol purple in acetonitrile

The formation of an ion-association complex (IA) between sulfonephthalein dye and basic nitrogen-containing compound in an organic solvent medium has been for the first time used to develop an automated SIA method. In highly polar aprotic solvents, the tautomeric equilibrium for such dyes is strongly shifted towards the colorless lactonic form. The addition of a basic nitrogen-containing substance leads to the formation of IA with a highly colored quinonoid form, which is accompanied by an increase in the absorbance of the dye band at approximately 400 nm. Protonation of pyridine nitrogen in loratadine, structure and binding places of IA were shown using quantum-chemical calculations. The very simple, direct and non-extraction spectrophotometric SIA method with high throughput of 43 h-1 was developed based on the formation of IA between loratadine and bromocresol purple in the medium of acetonitrile used both as solvent and carrier. The calibration graph was linear in the concentration range from 1.0 to 20 mg L-1 with correlation coefficient of 0.9992. The developed method was successfully applied to the analysis of pharmaceutical formulations.

Eco-Friendly Simultaneous Estimation of Ponceau 4R and Carmoisine Employing an Analytical Quality by Design-Aided RP-HPLC Method in Commercial Food Samples Utilizing a Green Ultrasound-Assisted Extraction Technique

BACKGROUND

Ponceau 4R (E124) and carmoisine (CMS; E122) are frequently utilized azo synthetic dyes in the food industry owing to their aesthetically pleasing coloration and broad consumer acceptability. It is imperative to prioritize environmentally favorable technologies for quantifying these dyes, as excessive consumption of these poses significant health risks.

OBJECTIVE

The primary objective of this research was to establish a reversed-phase (RP)-HPLC method that could simultaneously detect Ponceau 4R and CMS, implementing green analytical chemistry (GAC) and analytical quality by design (AQbD), using an ultrasound-assisted extraction (UAE) technique in commercial food samples.

METHODS

An Agilent Eclipse Plus column (C18, 250 × 4.6 mm id, 5 µm) was utilized for effective separation with a mobile phase of ethanol-acetate buffer pH 5 (60:40, v/v), flow rate of 1 mL/min, and detection wavelength of 515 nm. Critical variables selected for method optimization were ethanol percentage and flow rate, determined using central composite design (CCD). In order to adhere to the 12 principles of green chemistry, hazardous solvents were substituted with ethanol, which is distinguished by its ease of use, effectiveness, and ecological sustainability. The greenness assessment was conducted utilizing the green analytical procedure index (GAPI), analytical eco-scale (AES), and analytical greenness metrics (AGREE).

RESULTS

The respective retention times for Ponceau 4R and CMS were 2.276 and 3.450 min. The recovery rate of Ponceau 4R and CMS fluctuated between 70% and 102% and 80% and 102%, respectively, across various marketed food samples. The procedure passed validation in accordance with the International Conference on Harmonization Q14 guidelines.

CONCLUSION

The devised method demonstrates that the validation parameters like linearity, precision, sensitivity, and reproducibility are within the specified limits of ICH guidelines. The greenness assesment tools GAPI, AES, and AGREE produced the most favorable results.

HIGHLIGHTS

In future, environmentally sustainable, solvent-based, robust AQbD methodologies for assessing varieties of food colorants may be adopted and improved commercially.

AGREE and ESA for Greenness Assessment of a Novel Validated RP-HPLC Method for Simultaneous Determination of Aspirin, Warfarin and Clopidogrel in Rat Plasma: Application to Pharmacokinetic Study of the Possible Interaction between the Three Drugs

The green profile of the developed method is assessed and compared with previously reported methods. Percutaneous coronary intervention is a procedure where a catheter is utilized to place a stent in order to facilitate opening of the blood vessels in the heart. Triple antithrombotic therapy includes oral anticoagulation as warfarin and dual antiplatelet therapy (composed of aspirin and clopidogrel bisulfate). The aim of the current study was to evaluate the pharmacokinetic parameters of ASP, WAR and CLP and to investigate the possible interaction between the three drugs upon co-administration in rats. A selective and precise RP-HPLC method was developed for the simultaneous determination of ASP, WAR and CLP in rat plasma. Pharmacokinetic study was conducted in rats that received ASP, WAR and CLP as an application of the developed method. From the statistical evaluation of the pharmacokinetic parameters, it was observed that the co-administration of ASP, WAR and CLP significantly increased the ASP and CLP bioavailability in rats. A significant drug-drug interaction was confirmed in the current study. The elevated Cmax of ASP and CLP upon the co-administration of ASP, WAR and CLP may explain the reported bleeding.

Development of Eco-Friendly Scattering and Fluorimetric Methods for the Determination of Clemastine Through Its Interaction with Eosin Y: Assessment of Whiteness, Blueness, and Greenness Tools

For the first time, clemastine was estimated in this work utilizing two validated resonance Rayleigh scattering (RRS) and fluorimetric methods. The methods relied on forming an association complex in an acidic medium between eosin Y reagent and clemastine. In the spectrofluorimetric approach, the investigated drug was quantified by quenching the fluorescence-emission intensity of eosin Y at 543.5 nm. The RRS method relied on enhancing the RRS spectrum at 331.8 nm, which is produced when eosin Y interacts with clemastine. Suitable conditions were established for the reaction to achieve maximum sensitivity. The linear values obtained from the spectrofluorimetric approach and the RRS method fall into the ranges of 0.2-1.5 µg mL- 1 and 0.25-2.0 µg mL- 1, respectively. It was established that the detection limits for these methods were 0.045 µg mL- 1 and 0.059 µg mL- 1, respectively. The developed methodologies yielded acceptable recoveries when used to estimate the quantity of clemastine in its pharmaceutical tablet dosage form. Regarding the use of greener solvents that were chosen, the suggested and reported methods were compared with the help of the Green Solvents Selecting (GSST) tool for assessing hazardous solvents to achieve sustainability. Furthermore, analytical Eco scale and comprehensive assessments of whiteness, blueness, and greenness were carried out utilizing Modified NEMI, ComplexGAPI, and AGREE evaluation tools. Additionally, recently developed tools such as BAGI and RGB 12 were applied to assess the blueness and the whiteness of the suggested methods.

A Green HPLC Approach to Florfenicol Analysis in Pig Urine

Florfenicol (FF) is a broad-spectrum antibiotic used to treat gastrointestinal and respiratory infections in domestic animals. Considering FF's rapid elimination via urine after drug treatment, its use increases concerns about environmental contamination. The objective of the study was to establish a sustainable chromatographic method for simple analysis of FF in pig urine to investigate the urinary excretion of FF after a single intramuscular administration of 20 mg FF/kg body weight. The urine sample was prepared using a centrifuge and regenerated cellulose filter, and the diluted sample was analyzed. The method was validated in terms of linearity, the limit of detection (0.005 µg/mL) and quantitation (0.016 µg/mL), repeatability and matrix effect (%RSD ranged up to 2.5), accuracy (varied between 98% and 102%), and stability. The concentration-time profile of pig urine samples collected within 48 h post-drug administration showed that 63% of FF's dose was excreted. The developed method and previously published methods used to qualify FF in the urine of animal origin were evaluated by the National Environmental Method Index (NEMI), Green Analytical Procedure Index (GAPI) and Analytical GREENness Metric Approach (AGREE). The greenness profiles of published methods revealed problems with high solvents and energy consumption, while the established method was shown to be more environmentally friendly.

Microwave-assisted UV digestion of starch and skimmed milk powder: Environmentally friendly protocol for essential and toxic elements determination

The present work evaluated a microwave-assisted wet digestion method using diluted HNO3 with in situ UV radiation for the digestion of starch and skimmed milk powder for further metals determination by spectrometric plasma-based techniques. The sample digestion was conducted using an in situ UV lamp (electrodeless discharge lamp), and the digestion efficiency was improved by employing O2 (20 bar) and 2 mL 30 % H2O2 as auxiliary reagents. The accuracy of the proposed digestion method was evaluated by metals determination (Ca, Cd, Cu, Fe, K, Mg, Mo, Mn, Na, Pb, and Zn) in certificated reference material, which agreed with certified values (Student t-test <0,05). With the use of a UV lamp an environmentally friendly protocol was developed for starch and skimmed milk powder digestion using 0.1 mol L-1 HNO3 with auxiliary reagents (H2O2 or O2). The RCC value ranged from 0.9 to 1.2 % (starch and skimmed milk powder, respectively). The simultaneous cooling approach further improved the digestion efficiency (RCC <0,3 % for both samples), allowing to use milder digestion conditions, or even just water, being environmentally friendly, reducing the waste generation and reagents consumption, allowing food quality control through a greener approach.

Towards green extraction of bioactive natural compounds

The increasing interest in natural bioactive compounds is pushing the development of new extraction processes that may allow their recovery from a variety of different natural matrices and biomasses. These processes are clearly sought to be more environmentally friendly than the conventional alternatives that have traditionally been used and are closely related to the 6 principles of green extraction of natural products. In this trend article, the most critical aspects regarding the current state of this topic are described, showing the different lines followed to make extraction processes greener, illustrated by relevant examples. These include the implementation of new extraction technologies, the research on new bio-based solvents, and the development of new sequential process and biorefinery approaches to produce a full valorization of the natural sources. Moreover, the future outlook in the field is presented, in which the main areas of evolution are identified and discussed.

Removal of arsenic(V) using pure zeolite (PZ) and activated dithizone zeolite (ADZ) from aqueous liquids: application to green analytical chemistry

The primary aim of the present investigation was to evaluate the efficiency of pure zeolite and activated dithizone zeolite for arsenic(V) removal from aqueous solutions. The analytical eco-scale and analytical greenness for sample preparation results confirm that the proposed method is environmentally friendly. Zeolite adsorbents were characterized and tested for their ability to adsorb arsenic(V) from wastewater. Our study delved into arsenic(V) sorption behavior on pristine and activated zeolites. Through steady-state experiments using pure zeolite and activated dithizone zeolite, we examined the sorption of arsenic from aqueous solutions. We optimized operational parameters, including pH, adsorbent dosage, contact time, and arsenic(V) concentration. Our findings revealed that the Langmuir and Freundlich adsorption isothermal models were highly influential in fitting the experimental data, resulting in statistically significant outcomes. This study highlights the potential of zeolites as outstanding adsorbents for removing arsenic(V) from aqueous solutions. The calculated maximum adsorption capacity (qmax) of pure zeolite and activated dithizone zeolite was 18.2 and 21.1(mg/g), respectively, with R2 = 0.999. According to Freundlich's linear model, the experimental isothermal data indicated that activated dithizone zeolite has a higher value of kf constant and a lower value of the 1/n constant than that obtained for pure zeolite. These results imply favorable adsorption of arsenic(V) on activated dithizone zeolite.

A new green fluorimetric micelle complexation approach for reduction of the consumed solvent and quantification of avapritinib in biological fluids

Avapritinib (AVA) is the first medication authorized by the US-FDA in 2020 for the management of gastrointestinal stromal tumours (GISTs) that can't be treated by surgery. Cancer is among the most common causes of death worldwide and is the second most common cause of death after cardiovascular disease. Therefore, a quick, easy, sensitive, and straightforward fluorimetric approach was used to analyse AVA in pharmaceutical materials and blood plasma (pharmacokinetic). The suggested technique relies on 2% sodium dodecyl sulphate (SDS, pH 4) micellar system augmentation of the fluorescence of the tested drug. The technique demonstrated high relative fluorescence intensity (RFI) at 430 nm after excitation at 340 nm. Concentrations ranging from 20.0-400.0 ng mL-1 with a limit of quantitation of 9.47 ng mL-1 were used to obtain luminescence data for the studied medicine. In addition, the quantum yield of the AVA fluorescence was increased with the gradual addition of a surfactant at a concentration above its critical micellar level. This knowledge has been exploited to enhance the effectiveness of a spectrofluorometric technique for the estimation of AVA in human plasma (98.95 ± 1.22%) and uniformity tests with greenness assessments. The conditions for enhanced fluorescence were optimized and fully validated using US-FDA and International Conference on Harmonization (ICH) rules. This innovative strategy was expanded for AVA stability research in human plasma across various circumstances. This approach is an eco-friendly solution compared to traditional testing methods that use hazardous chemicals.