Applications and opportunities of experimental design for the dispersive liquid–liquid microextraction method – A review

Erucin-loaded chitosan coated solid lipid hybrid nanoparticles: An efficient drug delivery system for enhancing solubility and sustained release

This study investigates enhancing the solubility, bioavailability, and sustained release of erucin, a lipophilic compound from Eruca sativa seeds, using chitosan-coated lipid polymer hybrid nanoparticles (ER-LPHNPs). Optimized ER-LPHNPs were evaluated for in vitro and in vivo properties. The developed formulation was characterized using various techniques and studied for its toxicity on RAW 246.7 cell line and baker's yeast along with glucose uptake assay on baker's yeast and L6 cell line. ER-LPHNPs (size: 112.3667 ± 1.76 nm, PDI: 0.244 ± 0.012, ZP: +33.6 mV) showed spherical morphology by HR-TEM, FE-SEM, AFM and encapsulation efficiency exceeded 90 %, with sustained release at pH 7.4. FTIR confirmed the encapsulation of erucin and absence of drug-excipients covalent interactions. ER-LPHNPs and erucin were non-toxic to baker's yeast at concentrations up to 3000 μg/mL, with ER-LPHNPs enhancing glucose uptake over erucin and metronidazole. ER-LPHNPs also showed reduced toxicity on Raw 246.7 cells and significantly improved glucose uptake in L6 cell line. In vivo pharmacokinetics study demonstrated ER-LPHNPs increased drug's bioavailability by 256 %. Additionally, ER-LPHNPs enhanced the Cmax and Tmax of Erucin, which validates the sustained release of drug from the nanoparticles as compared to ER-CMC suspension. Thus, ER-LPHNPs act as a controlled nano-delivery system by addressing solubility, bioavailability, and sustained release challenges.

Experimental-design-based optimization of dispersive liquid-liquid microextraction coupled with gas chromatography-negative-ion chemical ionization-mass spectrometry for the determination of pyrethroids in agricultural products and drinks

Pyrethroids are synthetic chemicals that account for 16% of the international insecticide market and have been shown to be of varying toxicity to different species. There are various methods available for detecting pyrethroids in agricultural products, but these products must be pre-treated to remove interference from the food matrix, such as through dispersion liquid-liquid microextraction (DLLME). This study employed two experimental design methods to optimize the continuous and discontinuous experimental parameters of DLLME and investigated whether DLLME combined with GC-NICI-MS is effective for detecting pyrethroids in agricultural products. The Taguchi design with an L9(34) orthogonal array and response surface methodology were employed to optimize the discontinuous and continuous parameters of the DLLME process, respectively. To validate the performance of GC-NICI-MS after optimized DLLME, pyrethroids in mixed standard solutions at levels ranging from 0.02 to 50.00 µg/L were measured, and the resultant calibration curves were fitted. Adequate linearity was found for the six investigated pyrethroids (r = 0.9908-0.9960). The limits of detection and quantification ranged from 0.005 to 0.035 µg/L and 0.02 to 0.1 µg/L, respectively. The proposed approach simplifies the optimization of parameters compared to reported methods and achieves considerably lower limits of detection. The concept of mixed application based on the dual experimental design method can be applied to other regulated compounds to enhance the safety of agricultural products. The feasibility of the method was confirmed by successfully detecting pyrethroids in 13 types of teas, fruit, and vegetables.

The Effectiveness of Liquid-Phase Microextraction of Beta-Blockers from Aqueous Matrices for Their Analysis by Chromatographic Techniques

Beta-blockers are pharmaceuticals used to treat cardiovascular diseases such as hypertension, angina pectoris, and arrhythmia. Due to high consumption, they are continuously released into the environment, being detected in many aqueous matrices. The aim of this research is to test the effectiveness of two green liquid-phase microextraction procedures, such as dispersive liquid-liquid microextraction (DLLME) and solidification of floating organic droplet microextraction (SFOME) for the selective extraction of eight beta-blockers (atenolol, nadolol, pindolol, acebutolol, metoprolol, bisoprolol, propranolol, and betaxolol) from aqueous matrices for their analysis by gas chromatography (GC) or liquid chromatography (LC). The influence of extraction parameters, such as the type and volume of extraction and disperser solvents, and ionic strength were studied. The developed extraction procedures provide a good enrichment factor for six compounds (61.22-243.97), good extraction recovery (53.04-92.1%), and good sample cleaning for both extraction procedures. Good limits of detection (0.13 to 0.69 µg/mL for GC and 0.07 to 0.15 µg/mL for HPLC) and limits of quantification (0.39 to 2.10 µg/mL for GC and 0.20 to 0.45 µg/mL for LC) were obtained. The developed procedures were successfully applied to the analysis of selected beta-blockers in wastewater samples, proving their applicability to the real samples.

Dispersive liquid-liquid microextraction for the determination of urinary 8-hydroxy 2'-deoxyguanosine in COVID-19 patients by gas chromatography-mass spectrometry

COVID-19 disease has led to many deaths worldwide and early detection of people at a high risk of severe forms of this disease would greatly help physicians. The presence of oxidative stress biomarkers may help identify high-risk individuals early in the course of the disease. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) is a widely used biomarker for assessing endogenous oxidative DNA damage. In this study, the urinary 8-OHdG levels were determined in COVID-19 patients and COVID-19 patients with cancer by a dispersive liquid-liquid microextraction (DLLME) method using gas chromatography-mass spectrometry (GC-MS). The effects of essential parameters on the extraction method were investigated. The LOD and LOQ are equal to 1.7 nM and 5.1 nM, respectively. At varied concentrations of 8-OHdG (300, 400, and 600 nM), the relative standard deviation (RSD) ranged from 18.35% to 22.36%. The mean urinary 8-OHdG levels of cancer and COVID-19 patients were 13.20 ± 6.20 nmol mmol-1, while the mean levels in COVID-19 patients and healthy volunteers were 6.67 ± 5.80 nmol mmol-1 and 1.61 ± 1.72 nmol mmol-1, respectively. The results of this study showed that the level of 8-OHdG urine biomarkers in people with COVID-19 is significantly higher than in healthy people. In this study, the DLLME approach was used for the first time to determine the value of 8-OHdG using GC-MS. According to the results of this research, the DLLME method was successfully used as a biomarker of DNA oxidative stress for extracting 8-OHdG urine. Compared to other methods, this technique has advantages such as shorter extraction time and low cost.

Method development and optimization for dispersive liquid-liquid microextraction factors using the response surface methodology with desirability function for the ultra-high performance liquid chromatography quadrupole time of flight mass spectrometry determination of organic contaminants in water samples: risk and greenness assessment

A simple, cost effective, and efficient dispersive liquid-liquid microextraction method was developed and optimized for the determination of organic contaminants in different environmental water matrices followed by UHPLC-QTOF-MS analysis. In the preliminary experiments, the univariate optimization approach was used to select tetrachloroethylene and acetonitrile as extraction and disperser solvents, respectively. The significant factors influencing DLLME were screened using full factorial design, and the optimal values for each variable were then derived through further optimization using central composite design with desirability function. The optimal conditions were achieved with 195 μL of tetrachloroethylene as the extraction solvent, 1439 μL of acetonitrile as the disperser solvent, and a sample pH of 5.8. Under these conditions, the method provided detection limits ranging from 0.11-0.48 μg L-1 and recoveries ranging from 23.32-145.43% across all samples. The enrichment factors obtained ranged from 11.66-72.72. The proposed method was then successfully applied in real water samples. Only benzophenone was detected in the concentration range of 0.79-0.88 μg L-1 across all the water samples. The calculated risk quotient resulting from benzophenone exposure in water samples showed a low potential risk to human health and the aquatic ecosystem. The method was also evaluated for its environmental friendliness using various metrics tools such as Analytical Eco-Scale (AES), Green Analytical Procedure Index (GAPI), Analytical GREEnness (AGREE), Analytical Greenness for Sample Preparation (AGREEprep), and Sample Preparation Metric of Sustainability (SPMS). Only AES qualified the method as green while it was considered acceptable and sustainable when assessed using SPMS.

Exploration of supramolecular solvent-based microextraction for crystal violet detecting in water samples

This approach highlights the advantages of supramolecular solvents in a new microextraction model. The distinct properties and behavior of this supramolecular solvent provide enhanced extraction capabilities for detecting crystal violet (CV) in water samples. The methodical experimentation was executed to optimize the critical process parameters, providing maximum efficiency of crystal violet extraction at optimal conditions with pH set at 2.7, 186 μL of extraction solvent, extraction time of 3.5 min, and a salt amount of 3.1 % w/v, yielding the best results. Analytical data from extraction experiments under these optimal conditions demonstrated a high extraction percentage. The extraction model exhibited a linear response within the range of 10-800 ng mL-1 of crystal violet, with a detection limit of 2 ng mL-1. This model enables the measurement of CV in water samples with recovery rates exceeding 97 %, offering a straightforward and accessible approach for analysis.

Development of an orbital shaker-assisted fatty acid-based switchable solvent microextraction procedure for rapid and green extraction of amoxicillin from complex matrices: Central composite design

In this study, a cheap, fast and simple orbital shaker-assisted fatty acid-based switchable solvent microextraction (OS-FASS-ME) procedure was developed for the extraction of amoxicillin (AMOX) in dairy products, pharmaceutical samples and wastewater prior to its spectrophotometric analysis. Fatty acid-based switchable solvents were investigated for extracting AMOX. The key factors of the OS-FASS-ME procedure were optimized using a central composite design. The linearity of OS-FASS-ME procedure was in the range 5-600 ng mL-1 with a correlation coefficient of 0.991. In five replicate experiments for 20 ng mL-1 of AMOX solution, the recovery and relative standard deviation were 95.8% and 2.2%, respectively. Limits of detection and quantification were found 1.5 ng mL-1 and 5 ng mL-1, respectively. The accuracy, precision, robustness and selectivity of the OS-FASS-ME procedure were investigated in detail under optimum conditions. The OS-FASS-ME procedure was applied to milk, cheese, wastewater, syrups and tablets. A comparison of the results obtained from the reference method and the OS-FASS-ME method showed that the OS-FASS-ME procedure can be successfully applied to complex matrices.

Determination of capsaicin at trace levels in different food, biological and environmental samples by quadruple isotope dilution-gas chromatography mass spectrometry after its preconcentration

Despite the therapeutic properties of capsaicin for some diseases, it shows some side effects for human health. The goal of this study was to develop a precise and accurate analytical strategy for the trace determination of capsaicin in different food, biological and environmental samples including pepper, saliva and wastewater by gas chromatography-mass spectrometry (GC-MS) after spraying-based fine droplet formation-liquid phase microextraction (SFDF-LPME) and quadruple isotope dilution (ID4) method. Acetic anhydride was used as derivatizing agent, and the extraction method was used to enrich the analyte derivative to reach low detection limits. Under the optimum conditions, limit of detection (LOD) and limit of quantitation (LOQ) were determined to be 0.33 and 1.10 µg/kg, respectively. Percent recoveries calculated for SFDF-LPME-GC-MS method ranged between 84.1 and 131.7 %. After the application of ID4-SFDF-LPME-GC-MS method, percent recoveries were obtained in the range of 94.9 and 104.0 % (%RSD ≤ 2.8) for the selected samples. It is obvious that the isotope dilution-based method provided high accurate and precise results due to the elimination of errors during the derivatization, extraction and measurement steps.

Solvent-Focused Gas Chromatographic Determination of Thymol and Carvacrol Using Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction through Solidifying Floating Organic Droplets (USA-DLLME-SFO)

An ultrasound-assisted dispersive liquid-liquid microextraction by solidifying floating organic droplets, coupled to a form of temperature-programmed gas chromatography flame ionization detection, has been developed for the extraction and determination of thymol and carvacrol. This method utilizes undecanol as the extraction solvent, offering advantages such as facilitating phase transfer through solidification and enhancing solvent-focusing efficiency. The optimal gas chromatography conditions include a sample injection volume of 0.2 µL, a split ratio of 1:10, and a flow rate of 0.7 mL min-1. The extraction conditions entail an extraction solvent volume of 20 µL, a disperser solvent (acetone) volume of 500 µL, pH 7.0, 7.0% NaCl (3.5 M), a sample volume of 5.0 mL, an ultrasound duration of 10 min, and a centrifuge time of 7.5 min (800 rpm). These conditions enable the achievement of a high and reasonable linear range of 3.5 to 70. 0 μg mL-1 for both thymol and carvacrol. The detection limits are found to be 0.95 and 0.89 μg mL-1, respectively, for thymol and carvacrol. The obtained relative standard deviations, 2.7% for thymol and 2.6% for carvacrol, demonstrate acceptable precision for the purpose of quantitative analysis.

Experimental Design Application for Measuring Histamine in Tuna Fish Samples by Phenyl Isothiocyanate Derivation Method Using Ultra-Performance Liquid Chromatography

Histamine as an important biogenic amino acid was measured in tuna fish samples by ultra-performance liquid chromatography using a phenyl isothiocyanate derivative. Minitab software was used to design the experiment and investigate the effective factors during the process, which includes screening and optimization steps. A partial factorial design was used in the screening stage and a central composite design was used in the optimization. Effective parameters in histamine derivatized were examined in the screening step including triethylamine volume, phenyl isothiocyanate volume, reaction temperature, reaction time and mobile phase pH. Then, in the optimization, effective parameters were identified and finally, the calibration curve was drawn from a concentration of 0.5-10.0 μg.mL-1 for histamine derivatized and a correlation coefficient of 0.994 was obtained for histamine derivatized. The method detection limit was 0.36 μg.mL-1 and the limit of quantification (LOQ) was 1.19 μg.mL-1. The relative standard deviation of the method was obtained for concentrations of 1.0-100.0 μg.mL-1 in the range between 1.06 and 2.21%. The recovery method was obtained from 90.8 to 103.1% for measuring histamine derivatized in real fish samples.

Application of experimental design as a statistical approach to recover bioactive peptides from different food sources

Bioactive peptides (BAPs) derived from samples of animals and plants have been widely recommended and consumed for their beneficial properties to human health and to control several diseases. This work presents the applications of experimental designs (DoE) used to perform factor screening and/or optimization focused on finding the ideal hydrolysis condition to obtain BAPs with specific biological activities. The collection and discussion of articles revealed that Box Behnken Desing and Central Composite Design were the most used. The main parameters evaluated were pH, time, temperature and enzyme/substrate ratio. Among vegetable protein sources, soy was the most used in the generation of BAPs, and among animal proteins, milk and shrimp stood out as the most explored sources. The degree of hydrolysis and antioxidant activity were the most investigated responses in obtaining BAPs. This review brings new information that helps researchers apply these DoE to obtain high-quality BAPs with the desired biological activities.

Benchtop volatilomics supercharged: How machine learning based design of experiment helps optimizing untargeted GC-IMS gas phase metabolomics

Gas chromatography-ion mobility spectrometry (GC-IMS) plays a significant role in both targeted and non-targeted analyses. However, the non-linear behavior of IMS and its complex ion chemistry pose challenges for finding optimal experimental conditions using existing methodologies. To address these issues, integrating machine learning (ML) strategies offers a promising approach. In this study, we propose a hybrid strategy, combining design of experiment (DOE) and machine learning (ML) for optimizing GC-IMS conditions in non-targeted volatilomic/flavoromic analysis, with saffron volatiles as a case study. To begin, a rotatable circumscribed central composite design (CCD) is used to define five influential GC-IMS factors of sample amount, headspace temperature, incubation time, injection volume, and split ratio. Subsequently, two ML models are utilized: multiple linear regression (MLR) as a linear model and Bayesian regularized-artificial neural network (BR-ANN) as a nonlinear model. These models are employed to predict the response variables of total peak areas (PAs) and the number of detected peaks (PNs) in GC-IMS. The findings show that there is a direct correlation between the factors in GC-IMS and the PNs, suggesting that MLR is a suitable approach for building a model in this scenario. However, the PAs exhibit nonlinear behavior, suggesting that BR-ANN is better suitable to capture this complexity. Notably, Derringer's desirability function is utilized to integrate the PAs and PNs, and in this scenario, MLR demonstrates satisfactory performance in modeling the GC-IMS factors.

Statistical Tools to Optimize the Recovery of Bioactive Compounds from Marine Byproducts

Techniques for extracting important bioactive molecules from seafood byproducts, viz., bones, heads, skin, frames, fins, shells, guts, and viscera, are receiving emphasis due to the need for better valorization. Employing green extraction technologies for efficient and quality production of these bioactive molecules is also strictly required. Hence, understanding the extraction process parameters to effectively design an applicable optimization strategy could enable these improvements. In this review, statistical optimization strategies applied for the extraction process parameters of obtaining bioactive molecules from seafood byproducts are focused upon. The type of experimental designs and techniques applied to criticize and validate the effects of independent variables on the extraction output are addressed. Dominant parameters studied were the enzyme/substrate ratio, pH, time, temperature, and power of extraction instruments. The yield of bioactive compounds, including long-chain polyunsaturated fatty acids, amino acids, peptides, enzymes, gelatine, collagen, chitin, vitamins, polyphenolic constituents, carotenoids, etc., were the most studied responses. Efficiency and/or economic and quality considerations and their selected optimization strategies that favor the production of potential bioactive molecules were also reviewed.

Spectrophotometric determination of phenol impurity in phenoxyethanol and phenol index of drinking water and municipal wastewater effluent after salting-out assisted liquid phase microextraction (SA-LPME)

In this study, a novel and convenient analytical method based on salting-out-assisted liquid phase microextraction (SA-LPME) has been developed. A spectrophotometric technique was employed to quantify the concentration of phenol in drinking water and treated wastewater, as well as the phenol impurity in 2-phenoxyethanol (PE). To accomplish this, a solution containing dissolved PE was supplemented with 4-aminoantipyrine (4-AAP) and hexacyanoferrate. Subsequently, NaCl was added to induce the formation of a two-phase system, consisting of fine droplets of PE as an extractant phase in the aqueous phase. The resulting red derivative was then extracted into the extractant phase and separated through centrifugation. Finally, the absorbance of the extracted derivative was measured at 520 nm. The Response Surface Methodology (RSM) based on the Box-Behnken Design (BBD) was employed to optimize the influential factors, namely 4-Aminoantipyrine (4-AAP), buffer (pH = 10), hexacyanoferrate, and NaCl. By utilizing the optimal conditions (buffer: 50 μL, 4-AAP (1% w/v): 80 μL, hexacyanoferrate (10% w/v): 65 μL, and NaCl: 0.7 g per 10 mL of the sample), the limit of detection was determined to be 0.7 ng mL-1 and 0.22 μg g-1 for water and PE samples, respectively. The relative standard deviation (RSD) and correlation of determination (r2) obtained fell within the range of 2.4-6.8% and 0.9983-0.9994, respectively. Moreover, an enrichment factor of 65 was achieved for a sample volume of 10 mL. The phenol concentration in two PE samples (PE-1, PE-2), provided by a pharmaceutical company (Pars Sadra Fanavar, Iran), were determined to be 0.83 ± 0.05 μg g-1 and 2.70 ± 0.14 μg g-1, respectively. Additionally, the phenol index in drinking water and treated municipal wastewater was found to be 3.60 ± 1.06 ng mL-1 and 4.60 ± 1.17 ng mL-1, respectively. These mentioned samples were spiked in order to evaluate the potential influence of the matrix. The relative recoveries from PE-1, PE-2 samples, drinking water, and treated municipal wastewater samples were measured as 104.5%, 97.5%, 101.6%, and 107.8%, respectively, indicating no matrix effect.

Screening of variables affecting the selective leaching of valuable metals from waste motherboards' PCBs

The presence of valuable and hazardous metals in waste printed circuit boards, especially, motherboards, makes their recovery necessary as implies great economic and environmental advantages and develops urban mining processes. Hence, this research is focused on the selective leaching of Cu, Pb, and Sn as base metals using nitric acid and hydrochloric acid and Au, Ag, and Pd as precious metals using thiourea and sodium thiosulfate from waste motherboards' PCBs in a sequential eco-friendly two-stage process. Previously, thiourea and sodium thiosulfate were used as leaching agents to investigate their applicability for the leaching of metals from PCBs in a single-stage process. Screening experimental design was applied to screen the variables affecting the leaching process in order to evaluate their impact on the recovery of metals and select the significant factors. The results demonstrated that base and precious metals can be leached appropriately in two consecutive stages compared to a single-stage process. Nitric acid was found to be a much more efficient agent to leach Cu and Pb in comparison with hydrochloric acid which was more suitable for the leaching of Sn. In the case of precious metals, higher amounts of Au were leached using thiourea, whereas sodium thiosulfate was able to leach more Pd. Roughly similar results were obtained for the leaching of Ag using these leaching agents. Nitric acid concentration, average particle size, temperature, and leaching time were found to be significant to maximize the leaching of Cu and Pb and minimize that for Au, Ag, and Pd in the first stage. Initial pH was the only variable influencing the second stage, in particular, Au leaching by thiourea.

Ironing process optimization for enhanced properties in material extrusion technology using Box-Behnken Design

Material Extrusion (MEX) technology, a prominent process in the field of additive manufacturing (AM), has witnessed significant growth in recent years. The continuous quest for enhanced material properties and refined surface quality has led to the exploration of post-processing techniques. In this study, we delve into the ironing process as a vital processing step, focusing on the optimization of its parameters through the application of Design of Experiments (DoE), specifically the Box-Behnken Design (BBD). Through a systematic examination of ironing process parameters, we identified optimal conditions that resulted in a substantial reduction in surface roughness (Ra) by approximately 69%. Moreover, the integration of optimized ironing process parameters led to remarkable improvements in mechanical properties. For instance, the Ultimate Tensile Strength (UTS) saw a substantial improvement of approximately 29%, while the compressive strength (CS) showed an increase of about 25%. The flexural strength (FS) witnessed a notable enhancement of around 35%, and the impact strength (IS) experienced a significant boost of about 162%. The introduction of ironing minimizes voids, enhances layer bonding, and reduces surface irregularities, resulting in components that not only exhibit exceptional mechanical performance but also possess refined aesthetics. This research sheds light on the transformative potential of precision experimentation, post-processing techniques, and statistical methodologies in advancing Material Extrusion technology. The findings offer practical implications for industries requiring high-performance components with structural integrity and aesthetic appeal.

Optimization of [P6,6,6,14+]3[GdCl63-] magnetic ionic liquid assisted dispersive liquid-liquid microextraction for selective and sensitive determination of cadmium in environmental water and food

A simple and green hydrophobic magnetic ionic-liquid assisted dispersive liquid-liquid microextraction (MIL-DLLME) was optimized for the determination of trace cadmium (Cd (II)) in environmental and food samples by flame atomic absorption spectrophotometer. To achieve selective and sensitive extraction of Cd (II), four MILs were prepared and tested. Extraction parameters of the MIL-DLLME including pH, type and volume of the MIL, type and volume of dispersive solvent, extraction cycle, ionic strength and sample volume were investigated in detail and optimized by Box-Behnken design. Under optimum conditions, matrix effect, recovery study, intra-day and inter-day precision were performed for the MIL-DLLM. The analytical characteristics such as limit of detection, limit of quantification and pre-concentration factor were 0.17, 0.56 and 125 ng mL-1, respectively. The validation of the MIL-DLLME was evaluated by analysis of reference materials. Moreover, the accuracy of the results in the analysis of real samples was evaluated by standard addition and quantitative recoveries (91 ± 5-101 ± 2%) were achieved. The results obtained in the analysis of both reference materials and real samples showed that the MIL-DLLME has a selective applicability for cadmium.

Use of Doehlert Matrix as a Tool for High-Throughput Screening of Organic Acids and Essential Oils on Miniaturized Pork Loins, Followed by Lab-Scale Validation That Confirmed Tested Compounds Do Not Show Synergistic Effects against Salmonella Typhimurium

The many possible treatments and continuously changing consumer trends present a challenge when selecting antimicrobial interventions during pork processing. Thirty-five potential antimicrobials were screened at commercial working concentrations by individually adding them to miniaturized (69 cm3) disks of pork loin ends, followed by inoculation with Salmonella Typhimurium ATCC 19585. Two organic acids and nine essential oils significantly inhibited Salmonella counts on pork (p < 0.05). However, six compounds that represent different levels of significance (p < 0.05-p < 0.0001) were selected as independent variables to build a Response Surface Methodology model based on a Doehlert matrix (Doehlert Matrix-RSM): lactic acid 1.25%, formic acid 0.25%, cumin 0.25%, clove 0.25%, peppermint 0.5%, and spearmint 0.5%. The goal of the Doehlert Matrix-RSM was to study single and paired effects of these antimicrobials on the change in Salmonella over 24 h. The Doehlert Matrix-RSM model predicted that lactic acid, formic acid, cumin, peppermint, and spearmint significantly reduced Salmonella when added alone, while no significant interactions between these antimicrobials were found. A laboratory-scale validation was carried out on pork loin end slices, which confirmed the results predicted by the model. While this screening did not identify novel synergistic combinations, our approach to screening a variety of chemical compounds by implementing a miniaturized pork loin disk model allowed us to identify the most promising antimicrobial candidates to then formally design experiments to study potential interactions with other antimicrobials.

Research Progress of Perfluoroalkyl Substances in Edible Oil-A Review

Perfluoroalkyl substances (PFASs) have been widely used in different types of consumer and industrial applications such as surfactants, household cleaning products, textiles, carpets, cosmetics, firefighting foams, and food packaging because of their good stability and special physicochemical properties of hydrophobicity, oleophobicity, high temperature resistance, etc. Meanwhile, PFASs are considered an emerging organic pollutant due to their persistence and potential toxicity to human health. PFASs occur in edible oil, an important component of the global diet, mainly in three ways: raw material contamination, process contamination, and migration from oil contact materials. Thus, the occurrence of PFAS in edible oils has drawn more and more attention in recent years. In this work, the pertinent literature of the last two decades from the Web of Science database was researched. This review systematically addressed the potential sources, the contamination levels, and the progress of the determination of PFASs in edible oil. It aims to provide a relatively whole profile of PFASs in edible oil, render assistance to minimise human exposure to PFASs, and standardise the detection methods of perfluoroalkyl substances in edible oil.

Optimization of vortex-assisted hydrophobic magnetic deep eutectic solvent-based dispersive liquid phase microextraction for quantification of niclosamide in real samples

In this manuscript, a green and fast vortex-assisted hydrophobic magnetic deep eutectic solvent-based dispersive liquid phase microextraction (VA-HMDES-DLPME) method was developed for the selective extraction and determination of niclosamide in read samples, including rice, medicine tablets, and water samples. Here, hydrophobic magnetic deep eutectic solvents were used as the extracting solvent without requiring any centrifugation step. In the light of preliminary experiments, important parameters, such as volume of extraction solvent, pH, acetonitrile volume and vortex time, affecting the extraction efficiency of niclosamide were optimized using a Box-Behnken design. The linear dynamic range (0.25-120 µg/L), the limit of detection (0.08 µg/L), the limit of quantitation (0.25 µg/L), preconcentration factor (180), and enrichment factor (130) of the method were determined using optimized data. In particular, the validation parameters of the optimized VA-HMDES-DLPME, including robustness, matrix effect accuracy, and precision, were investigated. In addition to this, intra- and inter-day precisions were determined as ≤3.5 % and ≤4.1%, respectively. Finally, the optimized method was successfully used for the extraction of niclosamide in the selected samples prior to spectrophotometric analysis.

In situ formation of chloroform for dispersive liquid-liquid microextraction of some aromatic amines from aqueous samples optimized by central composite design prior to GC-MS analysis

In the current research, an in situ solvent formation-liquid phase microextraction method based on chloroform has been introduced as an efficient sample preparation procedure and applied for the extraction and preconcentration of some aromatic amines from wastewaters. In this method, chloral hydrate (2,2,2-trichloroethane-1,1-diol) was added to an alkaline solution of the samples in order to form chloroform as an extraction solvent in the sample solution. Thus, the selected analytes were transferred from the aqueous solution into the tiny droplets of the produced chloroform. Following this, the extracted and enriched analytes were quantified using a gas chromatograph-mass spectrometer. Experimental conditions of the proposed method including the chloral hydrate amount, salt effect, extraction time, and sodium hydroxide concentration were studied and optimized by a central composite design approach. By the offered method, high enrichment factors (292-324) with satisfactory extraction recoveries (82-91%), low limits of detection (0.26-0.39 ng mL^-1), and proper repeatability (relative standard deviations ≤6.3% for intra- and inter-day precisions) were achieved under optimum conditions. Eventually, the suggested method was assessed through the quantification of aromatic amines in aqueous samples.

Dispersive liquid-liquid microextraction and Monte Carlo simulation of margin of safety for octocrylene, EHMC, 2ES, and homosalate in sunscreens

Dispersive liquid-liquid microextraction (DLLME) using a floating organic drop has been optimized and used for the sample preparation of four commonly used ultraviolet filter (UVF) substances in sunscreens. Plackett-Burman experimental design was used to screen 10 variables in DLLME. The most significant variables were then optimized by using a response surface method with a Box-Behnken design. DLLME followed by an optimized HPLC identified octocrylene, 2-ethylhexyl-4-methoxycinnamate, ethylhexyl salicylate, and homosalate as the frequently found UVFs in commercial sunscreens. The systemic exposure dosage and margin of safety (MoS) for the identified UVFs were estimated using in-use concentrations and application patterns. The average systemic exposure dosage values for octocrylene, 2-ethylhexyl-4-methoxycinnamate, ethylhexyl salicylate, and homosalate were 0.52, 0.61, 0.020, and 0.079 mg/kg body weight per day, respectively. Whereas the average MoS values for individual UVFs ranging from 296 to 3160 were all significantly higher than the limit value of 100, the combined exposure risks were slightly above the limit. The probabilistic health risk assessment using Monte Carlo simulation revealed that the combined MoS values were (mean, 10‰, 90‰) 342, 119, and 441, respectively. Regarding the usage of sunscreen cosmetics containing the UVFs studied, these results indicate a safety concern for those who apply multiple UVF products.

Design of experiments (DoE) to develop and to optimize extraction of psychoactive substances

The design of experiments (DoE) method was employed to optimize the adsorption processes of seven psychoactive substances in magnetic solid phase extraction. Fe₃O₄/GO/ZIF-8 was utilized as an adsorbent for the efficient extraction of psychoactive substances from environmental water samples. The analytes were ephedrine, methylephedrine, amphetamine, methamphetamine, morphine, papaverine, and thebaine, which were determined by ultrahigh performance liquid chromatography-tandem mass spectrometry. Plackett-Burman design was employed to identify the significant factors responsible for adsorption, and Box-Behnken design was used for further optimization to obtain the optimum values for each variable. The predicted and experimental values were found to be in good agreement. The coefficient of determination (R²) values of 0.9500-0.9976 indicated that the model was significant. The linear ranges were 1-100 ng mL^-1, and the correlation coefficient was good (r² ≥ 0.995). The EF with values of about 2.5 was obtained with recoveries in the range of 74.92-94.47%. The limits of detection (LOD) and limits of quantification (LOQ) were 0.086-0.353 ng mL^-1 and 0.286-1.175 ng mL^-1, respectively. The intra-day and inter-day RSDs were in the range of 0.17-1.87% and 0.06-2.21%, respectively. By using the DoE method, the errors associated with inferring the influence and interaction between various factors can be reduced. The combination of MSPE and DoE improves the recovery, precision, and simultaneous detectability of the target analytes. It has a high potential for psychoactive substance analysis in environmental water.

Poly-(MMA-IL) filter paper: A new class of paper-based analytical device for thin-film microextraction of multi-class antibiotics in environmental water samples using LC-MS/MS analysis

A paper-based polymeric ionic liquid (p-Poly-(MMA-IL)) was successfully developed by grafting the polymeric ionic liquid on the surface of commercial filter paper (FP) by using the dipping method, presenting a new cost-effective film. The newly developed p-Poly-(MMA-IL) FP was then applied as a paper-based thin-film microextraction (p-TFME) analytical device to extract 14 compounds as representative of five groups of antibiotic drugs, which were sulfonamides, tetracyclines, fluoroquinolones, penicillin and macrolides in environmental water samples. Besides, p-Poly-(MMA-IL) FP, p-Poly-(MMA) FP, and unmodified filter paper were successfully characterised by FTIR, NMR, FESEM, TGA, and XRD techniques. They underwent significant parameters optimisation, which affected the extraction efficiency. Under optimal conditions, the proposed (p-Poly-(MMA-IL) FP-TFME) device method was evaluated and applied to analyse multi-class antibiotic drugs in environmental water samples by using a liquid chromatography-mass spectrometry (LC-MS). The validation method showed that a good linearity (0.1 μg L^-1 - 500 μg L^-1) was noted (R² > 0.993, n = 3). Detection and quantification limits were within 0.05 μg L^-1 - 4.52 μg L^-1 and 0.15 μg L^-1 - 13.6 μg L^-1, respectively. The relative standard deviation (RSD) values ranged at 1.4%-12.2% (intra-day, n = 15) and 4.4%-11.0% (inter-day, n = 10). The extraction recoveries of environmental water samples ranged from 79.1% to 126.8%, with an RSD of less than 15.4% (n = 3). The newly developed paper-based polymeric ionic liquid (p-Poly-(MMA-IL) FP) for analysis of multi-class antibiotic drugs under the p-TFME analytical device procedure was successfully achieved with limited sample volume and organic solvent, fast extraction, and feasible in daily analysis. The detection concentration and relative RSD of multi-class antibiotics determined in various environmental water samples by the proposed method (n = 5) were within 0.44 μg L^-1 - 54.41 μg L^-1 and 0.69%-15.56%, respectively. These results signified the potential of the p-Poly-(MMA-IL) FP-TFME device as an efficient, sensitive and environmentally friendly approach for analysing antibiotics.

Dispersive liquid-liquid microextraction based on a supramolecular solvent followed by high-performance liquid chromatographic analysis of lignans in Forsythiae Fructus

A supramolecular solvent-based dispersive liquid-liquid microextraction was proposed for the extraction and determination of lignans in Forsythiae Fructus combined with high-performance liquid chromatography. The supramolecular solvent, consisting of tetrabutylammonium bromide and n-hexanol, was mixed with the sample solution to extract the analytes by a vortex. After accomplishing the extraction, the extraction phase was separated by centrifugation and collected for high-performance liquid chromatography analysis. In this work, the important extraction variables such as the type and amount of extraction solvent, pH and salt amount in the sample phase, and extraction time were optimized. The synthesis of supramolecular solvent was studied and its microstructure was characterized by transmission electron microscopy. Under the optimal conditions, the analytes' enrichment factors were between 6 and 170 for the proposed procedure. Satisfactory linear ranges (r ≥ 0.99), detection limits (0.025-0.4 ng/ml), precisions (< 9.2%), and accuracies (recoveries: 96.5%-104.8%) were obtained. The method has been successfully applied to the preconcentration of lignans in Forsythiae Fructus with simple and rapid operation, low cost, and environmental friendliness.

Application of Design of Experiments in the Development of Self-Microemulsifying Drug Delivery Systems

Oral delivery has become the route of choice among all other types of drug administrations. However, typical chronic disease drugs are often poorly water-soluble, have low dissolution rates, and undergo first-pass metabolism, ultimately leading to low bioavailability and lack of efficacy. The lipid-based formulation offers tremendous benefits of using versatile excipients and has great compatibility with all types of dosage forms. Self-microemulsifying drug delivery system (SMEDDS) promotes drug self-emulsification in a combination of oil, surfactant, and co-surfactant, thereby facilitating better drug solubility and absorption. The feasible preparation of SMEDDS creates a promising strategy to improve the drawbacks of lipophilic drugs administered orally. Selecting a decent mixing among these components is, therefore, of importance for successful SMEDDS. Quality by Design (QbD) brings a systematic approach to drug development, and it offers promise to significantly improve the manufacturing quality performance of SMEDDS. Furthermore, it could be benefited efficiently by conducting pre-formulation studies integrated with the statistical design of experiment (DoE). In this review, we highlight the recent findings for the development of microemulsions and SMEDDS by using DoE methods to optimize the formulations for drugs in different excipients with controllable ratios. A brief overview of DoE concepts is discussed, along with its technical benefits in improving SMEDDS formulations.

Updating the status quo on the extraction of bioactive compounds in agro-products using a two-pot multivariate design. A comprehensive review

Extraction is regarded as the most crucial stage in analyzing bioactive compounds. Nonetheless, due to the intricacy of the matrix, numerous aspects must be optimized during the extraction of bioactive components. Although one variable at a time (OVAT) is mainly used, this is time-consuming and laborious. As a result, using an experimental design in the optimization process is beneficial with few experiments and low costs. This article critically reviewed two-pot multivariate techniques employed in extracting bioactive compounds in food in the last decade. First, a comparison of the parametric screening methods (factorial design, Taguchi, and Plackett-Burman design) was delved into, and its advantages and limitations in helping to select the critical extraction parameters were discussed. This was followed by a discussion of the response surface methodologies (central composite (CCD), Doehlert (DD), orthogonal array (OAD), mixture, D-optimal, and Box-Behnken designs (BBD), etc.), which are used to optimize the most critical variables in the extraction of bioactive compounds in food, providing a sequential comprehension of the linear and complex interactions and multiple responses and robustness tests. Next, the benefits, drawbacks, and possibilities of various response surface methodologies (RSM) and some of their usages were discussed, with food chemistry, analysis, and processing from the literature. Finally, extraction of food bioactive compounds using RSM was compared to artificial neural network modeling with their drawbacks discussed. We recommended that future experiments could compare these designs (BBD vs. CCD vs. DD, etc.) in the extraction of food-bioactive compounds. Besides, more research should be done comparing response surface methodologies and artificial neural networks regarding their practicality and limitations in extracting food-bioactive compounds.

Mycotoxin Contamination in Hazelnut: Current Status, Analytical Strategies, and Future Prospects

Hazelnuts represent a potential source of mycotoxins that pose a public health issue due to their increasing consumption as food ingredients worldwide. Hazelnuts contamination by mycotoxins may derive from fungal infections occurring during fruit development, or in postharvest. The present review considers the available data on mycotoxins detected in hazelnuts, on fungal species reported as infecting hazelnut fruit, and general analytical approaches adopted for mycotoxin investigation. Prompted by the European safety regulation concerning hazelnuts, many analytical methods have focused on the determination of levels of aflatoxin B1 (AFB1) and total aflatoxins. An overview of the available data shows that a multiplicity of fungal species and further mycotoxins have been detected in hazelnuts, including anthraquinones, cyclodepsipeptides, ochratoxins, sterigmatocystins, trichothecenes, and more. Hence, the importance is highlighted in developing suitable methods for the concurrent detection of a broad spectrum of these mycotoxins. Moreover, control strategies to be employed before and after harvest in the aim of controlling the fungal contamination, and in reducing or inactivating mycotoxins in hazelnuts, are discussed.

Application of phosphonium deep eutectic solvents as extractants in ultrasound-assisted dispersive liquid-liquid microextraction for preconcentration of trace amounts of herbicides in drainage ditches waters

In this study, an efficient preconcentration method was presented that is based on dispersive liquid-liquid microextraction taking the advantage of newly synthesized phosphonium deep eutectic solvents used as extractants and ultrasound probe as a dispersing agent. The extracts obtained were analyzed by high-performance liquid chromatography. To optimize the five most important factors for the microextraction procedure a central composite design plan was used. Under optimal conditions (140 μl of extractant, 60 mg of NaCl, pH = 2.0, 120 s of extraction time with ultrasound probe as the dispersing agent, 16 min of centrifugation for phase separation), the proposed method allowed to achieve good precision with RSD between 3.2% and 9.7% at 1.0, 5.0 and 40.0 ng ml levels. The preconcentration factors were equal to 42, 39, and 41, and the limits of detection 0.128, 0.103, and 0.135 ng/ml for dicamba, 2-methyl-4-chlorophenoxyacetic acid, and 2-methyl-4-chlorophenoxypropionic acid, respectively. The proposed method was successfully applied for the determination of chlorophenoxy acid herbicides in water samples from drainage ditches with a good recovery in the range of 70%-93%.

Analytical Performance of Electromembranes as a Tool for Nanoconcentrations of Silver in Waters

Electromembranes increase the efficiency of metal transport in liquid-phase microextraction systems by applying an electric potential, which accelerates the transport. Nevertheless, to get high extraction percentages in short extraction times it is necessary to take into account a great variety of factors, and multivariate optimization techniques are the best alternative to determine the most influential variables and to optimize the extraction process. In this work, a fractional factorial design was applied to determine the most influential variables in the extraction of silver by electromembranes. Thus, the effect of tri-isobutylphosphine sulphide (Cyanex 471x) concentration in the organic solution, sodium thiosulphate concentration in the acceptor solution, nitrate concentration in the sample solution, extraction time, stirring rate and electric potential on the enrichment factor were studied. Once the most important variables were selected, a small composite design (Draper-Lin) was used to obtain their optimal values to maximize the enrichment factor. Under these conditions, an experimental enrichment factor of 49.91 ± 3.95 was achieved after 22 min. Finally, the effect of saline matrix on the enrichment factor was tested and the optimized system was successfully applied to analyse silver concentrations at ultratrace levels, within the range of 7-29 ng·L^-1 in different real seawater samples.

Vortex-assisted supramolecular solvent dispersive liquid–liquid microextraction of ketoprofen and naproxen from environmental water before chromatographic analysis: response surface methodology optimisation

A microextraction procedure that is rapid and simple to extract and preconcentrate ketoprofen and naproxen is proposed. An environmentally friendly supramolecular solvent was applied as an extraction solvent and proved to be efficient in the extraction of ketoprofen and naproxen from environmental water. The design of experiment approach was used to screen, optimize significant parameters, and determine optimum experimental conditions. Under optimized experimental conditions, the vortex-assisted supramolecular solvent dispersive liquid–liquid microextraction provided a good linearity (0.57–700 µg L−1), low limits of detection (0.17–0.24 µg L−1) and extraction reproducibility below 9%. The high percentage relative recoveries (93.6–101.4%) indicated that the method is not affected by matrix. The practical applicability of the method was assessed by analysing ketoprofen and naproxen in river water and effluent wastewater samples. Both analytes were found in effluent wastewater.

Study and optimization of oil-in-water emulsions formulated by low- and high-frequency ultrasounds

OBJECTIVE

A combined treatment using both low-frequency (20 kHz) and high-frequency ultrasounds (1.63 MHz) is a promising new process to stabilize emulsions with minimalist formulation. In order to optimize process parameters, a Doehlert experimental design was performed with oil-in-water emulsions, presently used for cosmetic products, composed of water, caprylic/capric triglycerides and oleic acid.

METHODS

Effects of treatment time, oil content and oleic acid content were studied on emulsion properties (droplet size, polydispersity index, ζ-potential and yield of oil incorporation) and on emulsion stability after a 28-day storage (creaming index, Turbiscan stability index (TSI) and oil release).

RESULTS

From experimental data, a model was established that allowed to study effects of each parameter and their interactions on emulsion formation and stability. Oleic acid content had a great impact on emulsion formation: It reduced droplet size, PDI and ζ-potential and increased yield of oil incorporation. However, a critical value could be highlighted, beyond which oleic acid effects reversed. Treatment time had an important beneficial effect on emulsion stability as it decreased creaming index, TSI and oil release after 28 days of storage. Oil content had a negative effect on emulsion formation and on emulsion stability. However, treatment time and oil content often had a beneficial synergistic effect.

CONCLUSION

The optimized conditions for emulsion processing were obtained through a desirability approach. They were experimentally validated.

In-situ sorbent formation for the extraction of pesticides from honey

An organic polymer was re-precipitated in solution to use as an adsorbent in dispersive solid phase extraction of some pesticides from honey samples prior to their determination by high performance liquid chromatography-tandem mass spectrometry. In this approach, different deep eutectic solvents were prepared using lysine and their ability in elution of the analytes from the adsorbent surface were tested. A diluted honey solution was transferred into a glass test tube and then a solution of polystyrene dissolved in dimethylformamide was injected into the solution. By doing this, polystyrene re-precipitated in the solution and dispersed in whole parts of it as many tiny particles. Then the mixture was centrifuged and the adsorbed analytes on the particles were eluted using a proper hydrophilic deep eutectic solvent. Central composite design approach was used for optimization of effective parameters. The limits of detection and quantification were in the ranges of 0.06-0.20 and 0.22-0.69 ng/g, respectively. The calibration curves obtained by matrix-matched standard solutions were linear in the range of 0.69-500 ng/g with coefficient of determinations ≥0.9962. The method provided high extraction recoveries (70-99%) and enrichment factors (140-198), and an acceptable precision (relative standard deviations ≤7.1%). This article is protected by copyright. All rights reserved.

Determination of benzotriazole and benzothiazole derivatives in tea beverages by deep eutectic solvent-based ultrasound-assisted liquid-phase microextraction and ultrahigh-performance liquid chromatography-high resolution mass spectrometry

Benzotriazole (BTRs) and benzothiazole (BTHs) derivatives are a group of high production volume chemicals with emerging health concern, which found in tea beverages raising potential risks for food safety and human health. The present work describes a simple method using a "green" deep eutectic solvent (DES) based-ultrasound-assisted liquid-phase microextraction (UALPME) to rapidly extract BTRs and BTHs from tea beverages, and then applying UHPLC-electrospray ionization (+)-quadrupole time-of-flight mass spectrometry for detection and quantification. To overcome the challenges related to different experimental conditions, a Factorial Multilevel Categoric Design and a Face Centered Central Composite Design were applied to screen and optimize the parameters for the DES-UALPME procedure, respectively. After optimization, the method was validated and shown to possess low limits of quantification (LOQs; 1.5-12 ng mL^-1), high precision (3-13%), and satisfactory accuracy (65-107%). The developed method was then successfully applied for the analysis of some selected BTRs and BTHs in tea beverages.

An enhanced dispersive liquid–liquid microextraction method based on solidification of floating organic drops for the determination of pyrethroid pesticides in tea infusions

A novel enhanced dispersive liquid–liquid microextraction method based on solidified floating organic solvents containing [P4,4,4,12][PF6] and a hydrophobic solvent mixture for the determination of four pyrethroid insecticides in tea infusions.

Determination of multiple drugs of abuse in human urine using dispersive liquid–liquid microextraction and capillary electrophoresis with PDA detection

A new method was developed for pre-concentration and determination of multiple drugs of abuse in human urine using dispersive liquid–liquid microextraction (DLLME) and capillary electrophoresis (CE) with photodiode array detection. The method was based on the formation of tiny droplets of an organic extractant in the prepared sample solution using water-immiscible organic solvent (chloroform) dissolved in water-miscible organic dispersive solvent (isopropyl alcohol). The organic phase, which extracted eight drugs of abuse from the prepared urine solution, was separated by centrifugation. The sedimented phase was transferred into a small volume CE auto-sampler vial with 10 µL of 1% HCl methanol solution and evaporated to dryness. The residue was reconstituted in lidocaine hydrochloride (internal standard) aqueous solution and introduced by electrokinetic injection into CE. Under the optimum conditions, acceptable linear relationship was observed in the range of 3.0–500 ng/mL with the correlation coefficient (r) of 0.9982–0.9994 for spiked urine samples. The limit of detection (LOD) (S/N = 3) was estimated to be 1.0 ng/mL. A recovery of 75.7%–90.6% was obtained for spiked samples. The mean relative error (MRE) was within ±7.0% and the relative standard deviation (RSD) was less than 6.9%. The proposed DLLME-CE procedure offers an alternative analytical approach for the sensitive detection of drugs of abuse in real urine samples.

Key points

The dispersive liquid-liquid microextraction (DLLME) was involved for the determination of drugs in urine with capillary electrophoresis with photodiode array detection (CE-PDA).

Good linearity, sensitivity, recovery and precision were achieved.

The proposed method was eco-friendly with microliter scale solvent consumption.

Dispersive liquid-liquid microextraction based on deep eutectic solvent for elemental impurities determination in oral and parenteral drugs by inductively coupled plasma optical emission spectrometry

A simple, fast, sensitive and green pretreatment method for determination of Cd, Co, Hg, Ni, Pb and V in oral and parenteral drug samples using inductively coupled plasma optical emission spectrometry (ICP OES) has been developed. According to United States Pharmacopoeia (USP), those metals must be reported in all pharmaceutical products for quality control evaluation (i.e., elemental impurities from classes 1 and 2A of USP Chapter 232). To improve the analytical capabilities of ICP OES, a dispersive liquid-liquid microextraction (DLLME) has performed using a safe, cheap and biodegradable deep eutectic solvent (DES) as extractant solvent (a mixture of 2:1 M ratio of DL-menthol and decanoic acid). Seven parameters affecting the microextraction efficiency have carefully optimized by multivariate analysis. Under optimized conditions, the DES-based DLLME-ICP OES procedure improved limit of quantitation (LOQ) values on range from 12 to 85-fold and afforded an enrichment factor on average 60-times higher than those obtained to direct ICP OES analysis. Consequently, LOQ values for Cd, Co, Hg, Ni, Pb and V have been on average 10-times lower than target limits recommended for drugs from parenteral route of administration. Trueness has evaluated by addition and recovery experiments following USP recommendations for three oral drug samples in liquid dosage form and three parenteral drugs. Recovery and RSD values have been within the range of 90-109% and 1-6%, respectively. All analytes were below the respectives LOQ values, hence, lower than the limits proposed by USP Chapter 232.

Determination of Ketosteroids in Human Urine Using Dispersive Liquid-Liquid Microextraction and Ultra High-Performance Liquid Chromatography-High Resolution Mass Spectrometry

Abstract

A method is proposed for the determination of some ketosteroids in human urine, including enzymatic hydrolysis using β-glucuronidase from E. coli followed by dispersive liquid-liquid microextraction, derivatization of analytes with hydroxylamine, and detection by reversed-phase ultra-HPLC–quadrupole time-of-flight mass spectrometry. Optimization of extraction and derivatization conditions of the studied compounds made it possible to find that the highest recoveries were achieved using an acetone–chloroform mixture as a dispersant and an extractant, and the completeness of the derivatization reaction was achieved by thermostating the sample at 70°C for 90 min. The proposed method has high sensitivity (limits of detection in the range of 0.1–0.25 ng/mL) and a wide linearity range.