Microextraction by packed sorbent and HPLC–PDA quantification of multiple anti-inflammatory drugs and fluoroquinolones in human plasma and urine

The potential of lignocellulosic biomass for magnetic solid phase extraction of naproxen from saliva samples

This paper presents a study on the application of magnetic biochars derived from three distinct biomass sources: almond (AMBC), walnut (WMBC), and peanut (PMBC) shells for magnetic solid-phase extraction (MSPE) of naproxen, a non-steroidal anti-inflammatory drug, from human saliva prior to LC-MS analysis. The three magnetic biochars were synthesized and characterized through IR, XRD, SEM, and EDX analyses. This work explored the factors influencing extraction efficiency using these three bioadsorbents through experimental design. The results obtained revealed that magnetic biochar derived from almond shells demonstrated outstanding performance in terms of naproxen extraction, achieving an impressive yield of 100.2%. This remarkable efficiency was achieved by optimizing parameters, including a 12-minute extraction time, a 3.5 mL elution volume, a 10 mg adsorbent mass, and a 4-minute elution time. Consequently, this study established almond shell as a low-cost, environmentally friendly, and efficient magnetic biochar for extracting naproxen from human saliva. This superior performance was made possible due to the abundant lignocellulosic potential inherent in almond shell structures, surpassing that of the other two biochars. The combination of magnetic extraction with LC-MS demonstrates good linearity, with an R2 value equal to 0.9987. The limits of detection (LOD) and quantification (LOQ) are 0.013 and 0.047 μg L-1, respectively.

Preparation of a hydrophobic deep eutectic solvent and its application in the detection of quinolone residues in cattle urine

Enrichment for the detection of quinolone residues is usually cumbersome and requires large amounts of toxic organic reagents. Therefore, this study synthesized a low-toxicity hydrophobic deep eutectic solvent (DES) with DL-menthol and p-cresol, which was then characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and thermal analysis. A simple and rapid vortex-assisted liquid-liquid microextraction method was developed based on this DES for the extraction of eight quinolones from cattle urine. The optimal extraction conditions were screened by examining the DES volume, extraction temperature, vortex time, and salt concentration. Under the optimal conditions, the linear ranges of the eight quinolones were 1 ~ 100 μg/L with good linearity (r² was 0.998 ~ 0.999), and the limits of detection and quantification were 0.08 ~ 0.30 μg/L and 0.27 ~ 0.98 μg/L, respectively. The average extraction recoveries of spiked cattle urine samples were 70.13 ~ 98.50% with relative standard deviations below 13.97%. This method can provide a reference for the pre-treatment of quinolone residue detection.

Synthesis and Characterization of Electrospun Sorbent for the Solid-Phase Extraction of Fluoroquinolones in Human Plasma and Their UHPLC-PDA Determination

In this work we investigated the synthesis and the characterization of electrospun polyacrylonitrile (PAN) and polymethyl methacrylate (PMMA) stabilized in air, made in a 5:1 ratio, used as sorbent for the solid-phase extraction of fluoroquinolones in plasma samples and the following quantification in UHPLC-PDA. Preliminary analyses of viscosity were carried out on the polymer solution to be sure about the electrospinability. Characterizations were performed on the electrospun membrane to evaluate the morphology (SEM scanning electron microscopy and AFM atomic force microscopy), the thermal degradation behavior (TGA thermogravimetric analysis), the porosity and the surface area (BET, Brunauer Emmett Teller), and the quantitative and qualitative distribution of atomic structures (FTIR infrared analysis in Fourier transform and EDX Energy Dispersive X-ray analysis). A solid-phase extraction method was developed by studying parameters such as the amount of sorbent and the pH of the sample. Finally, a UHPLC-PDA method for the analysis of fluoroquinolones was developed and validated in accordance with the guidelines and successfully applied. The use of the prepared sorbent combined with UHPLC-PDA has allowed the development of a method whose strengths are its speed, accuracy, sensitivity, and high recoveries.

Disposable stochastic sensors for fast analysis of ibuprofen, ketoprofen, and flurbiprofen in their topical pharmaceutical formulations

Three disposable stochastic sensors based on maltodextrin (dextrose equivalent = 4-7) and nanostructures (copper monolayer, carbon monolayer and carbon-copper composite layer) deposited using cold plasma on copy paper were proposed for the fast analysis of ibuprofen, ketoprofen and flurbiprofen in pharmaceutical formulation samples. The widest linear concentration ranges recorded were: for ibuprofen 1 fmol/L - 1 mmol/L when the disposable stochastic sensor based on carbon monolayer was used, for ketoprofen 1 fmol/L - 1 mmol/L when the disposable stochastic sensors based on copper monolayer and carbon-copper composite layer were used, and for flurbiprofen 1 fmol/L - 10 mmol/L when the disposable stochastic sensor based on carbon-copper composite layer was used. The lowest limit of detection recorded for each non-steroidal anti-inflammatory drug was 1 fmol/L.

Fast Quantitative LC-MS/MS Determination of Illicit Substances in Solid and Liquid Unknown Seized Samples

Narcotic and psychotropic substances are natural, synthetic, or semisynthetic compounds that are present in both solid and liquid illicit products. The alterations effects on the central nervous system related to their use can be psycholeptic, psychoanaleptic, or psychodiseptic and are able to generate tolerance, addiction, or dependence phenomena, creating social and public order problems. In this scenario, the analytical evaluations that aim to determine these analytes in seized nonbiological samples, and which assume the character of judicial evidence, must meet high analytical requirements of reliability, transparency, and procedures uniformity at a national level. For the first time in the literature, the herein validated method is able to provide the simultaneous quantitative determination of 37 of the most common narcotic substances as well as the most commonly used excipients/adulterants found in seized illicit material. Additionally, the validated method can process both solid and liquid samples maintaining the precision and trueness levels (intraday and interday) in accordance with the U.S. Food and Drug Administration and European Medicines Agency international guidelines (<14.31 and <13.41%, respectively). Furthermore, it provides a simple and fast procedure for sample preparation using the dilute and shoot approach, exploiting the sensitivity and selectivity of the LC-MS/MS instrument configuration used and the signal acquisition in multiple reaction monitoring (MRM) mode (both positive and negative polarization modes).

Determination of levofloxacin by HPLC with fluorescence detection in human breast milk

Aim: A new HPLC method with fluorescence detection has been developed and validated for the determination of levofloxacin, one of the fluoroquinolone class antibiotics, in breast milk. Materials & methods: Chromatographic separation was carried out on a reversed phase C18 column with acetonitrile and 10 mM o-phosphoric acid (25:75, v/v) mobile phase composition. Moxifloxacin was used as internal standard and the peaks were detected by fluorescence detection. Results & conclusion: Calibration graph was found linearly within the range of 2.5-500 ng/ml. Limit of detection and limit of quantification were found to be 0.63 and 2.11 ng/ml, respectively. Mean absolute recovery was 96.18%. The developed method has been successfully applied to the determination of levofloxacin in human breast milk taken from two healthy volunteers.

Solid-phase extraction of non-steroidal anti-inflammatory drugs in human plasma and water samples using sol-gel-based metal-organic framework coating

In this research, the Cu-based metal-organic framework (MOF-199) was fabricated and coated on the stainless steel mesh as substrates through sol-gel procedure. Then the coated substrates were placed in a small column known as solid-phase extraction cartridge. The SPE based coated stainless steel mesh coupled with high-performance liquid chromatography-UV detector (HPLC-UV) was used for the fast extraction, and quantification of non-steroidal anti-inflammatory drugs (NSAIDs) from human plasma and water samples. To find optimum extraction conditions, the impacts of effective parameters on analytical performance like sample pH, sample volume, type, and volume of desorption solvent were optimized. At the optimized conditions, calibration graphs of analytes were linear in the concentration range of 0.03-300 ng mL^-1 for water samples, and 0.1-200 ng mL^-1 for plasma samples. The correlation coefficients were in the range of 0.9938 to 0.9989. Also, the limits of detection (LODs) were from 0.01 to 0.02 ng mL^-1 for water samples and 0.03 to 0.1 ng mL^-1 for plasma samples. The cartridge repeatability was studied at different values, and the relative standard deviations (RSDs%) were achieved between 3.5 and 5.1%. Consequently, this procedure was successfully used in the extraction and detection of NSAIDs in real water and plasma samples with relative recoveries ranged from 93.6 to 99.6%.

Microextraction by packed sorbent of selected pesticides in coffee samples employing ionic liquids supported on graphene nanosheets as extraction phase

This paper describes the synthesis, characterization, and use of ionic liquids supported on silica, functionalized with graphene oxide through covalent bonding (ILz/Si@GO), as sorbents for microextraction by packed sorbent (MEPS). Seven selected pesticides (diazinon, heptachlor, aldrin, endrin, dieldrin, endosulfan, and methoxychlor), used for the prevention of pests in coffee crops, and endosulfan sulfate-an endosulfan metabolite-were selected for this study as model compounds for evaluating the sorbent performance of the synthesized materials in the MEPS device. The cycles of each of the stages were previously optimized through univariate experiments to carry out the extraction. The ILz/Si@GO phase was compared to other sorbents used in MEPS (GO, DVB-MMA, C₄/SiO₂, C₈/SiO₂, ILz/SiO₂, and bare silica) and also with graphene functionalized through other methodologies, where ILz/Si@GO showed the best results. The material was characterized using a range of techniques. The selectivity of the sorbent material and its adsorption capacity were evaluated by gas chromatography coupled with tandem mass spectrometry. The precision and accuracy of the method showed a relative standard deviation lower than 10% and recoveries from 35 to 97%. Finally, the proposed method was employed for the determination of pesticide residues in coffee samples.

Evaluation of bioequivalence of two flurbiprofen axetil injections: A randomized, open-label, double-cycle, and crossover study

Flurbiprofen is a non-steroidal anti-inflammatory drug. We evaluated the bioequivalence of a new formulation of flurbiprofen axetil for injection and the reference drug ROPION (another kind of flurbiprofen axetil injection marketed for use) in healthy Chinese subjects. This is a single-centre, randomized, open-label, single-dose, two period crossover bioequivalence study. Each subject received a single intravenous injection at the dose of 50 mg under fasting. The drug was dissolved in 100 mL normal saline, and the injection was completed in 15 minutes. There was a 7-day washout period between the two administrations. The plasma concentrations of flurbiprofen were measured by LC-MS/MS, and descriptive statistics were used to describe the safety outcomes including adverse events (AEs) and adverse drug reactions (ADRs). Twenty-four subjects were enrolled in this study. Mean values of primary PK parameters (T_max , C_max , AUC_0-t , AUC_0-∞ , λ_z , T_1/2 ) were similar (P > 0.05). T_max for both products is 0.3 hours. The 90% confidence intervals (CIs) for peak concentration C_max ranged between 96.87% and 100.42%, and the area under curve AUC_0-t and AUC_0-∞ ranged between 99.09% and 104.29% and 98.97% and 104.29%, respectively. The 90% CIs for the geometric means and ratios of primary PK endpoints of flurbiprofen axetil injection to reference drug ranged between 98.97% and 104.29%. The adverse event rate of the test product was 8.3% and no serious adverse events (SAE) occurred in this clinical study. We concluded that the test product and the reference drug were bioequivalent and the safety was high in healthy Chinese subjects.

The effectiveness of using a molded sorbent: Modified polyvinylpyrrolidone for the combined treatment of chronic endometritis

OBJECTIVE

To improve the management of patients with chronic endometritis (CE) by using a molded sorbent-modified by polyvinylpyrrolidone (FSMP).

METHODS

This prospective study included 70 patients with CE divided into two groups: group 1 (n = 23) received traditional antibiotic therapy (from days 3 to 10 of the menstrual cycle); group 2 (n = 47), received antibiotics and FSMP was inserted from days 5 to 10.

RESULTS

At the end of therapy, group 1 had massive growth of pathogenic microflora in 21.7%, moderate growth in 69.6%, and no growth in 8.7% of cases. In group 2, after combined therapy, massive growth was observed in 4.3%, moderate growth in 44.7%, and no growth in 51.0%. In group 2 after 5 days, serum levels of interleukin-1β (IL-1β) were 1.9 times, of IL-6 were 7.0 times, and of IL-8 and IL-1 receptor antagonist were 1.3 times lower than in group 1. In uterine cavity aspirates, IL-1β decreased around 4.8 times, IL-6 by 11.8 times, IL-8 by 3.2 times, tumor necrosis factor-α by 3.9 times, and IL-1 receptor antagonist by 2.1 times in comparison to group 1.

CONCLUSION

Combined therapy of FSMP with antibiotics is more effective in treating CE, because it contributes to the almost complete elimination of pathogens and toxins from the uterine cavity, blocking the local pro-inflammatory cascade.

Fiberoptic-Coupled Spectrofluorometer with Array Detection as a Process Analytical Chemistry Tool for Continuous Flow Monitoring of Fluoroquinolone Antibiotics

Nowadays, there is an increasing need for sensitive real-time measurements of various analytes and monitoring of industrial products and environmental processes. Herein, we describe a fluorescence spectrometer in continuous flow mode in which the sample is fed to the flow cell using a peristaltic pump. The excitation beam is introduced to the sample chamber by an optical fiber. The fluorescence emitted upon excitation is collected at the right angle using another optical fiber and then transmitted to the fluorescence spectrometer which utilizes an array detector. The array detection, as a key factor in process analytical chemistry, made the fluorescence spectrometer suited for multiwavelength detection of the fluorescence spectrum of the analytes. After optimization of the experimental parameters, the system has been successfully employed for sensitive determination of four fluoroquinolone antibiotics such as ciprofloxacin, ofloxacin, levofloxacin, and moxifloxacin. The linear dynamic ranges of four fluoroquinolones were between 0.25 and 20 μg·mL-1, and the detection limit of the method for ciprofloxacin, ofloxacin, levofloxacin, and moxifloxacin were 81, 36, 35, and 93 ng·mL-1, respectively. Finally, the proposed system is carried out for determination of fluoroquinolones in some pharmaceutical formulations.

A Micellar-Enhanced Spectrofluorimetric Method for the Determination of Ciprofloxacin in Pure Form, Pharmaceutical Preparations and Biological Samples

A simple, fast and interference free spectrofluorimetric method was developed for the quantification of ciprofloxacin in its pure form, pharmaceutical preparations and in human plasma. The method is based on the enhancement of the weak fluorescence signal of drugs by the addition of sodium dodecyl sulphate (SDS) surfactant micelles in citrate buffer at pH 5.5. Different experimental parameters like buffers, surfactant type and concentration were investigated. The fluorescence intensity of ciprofloxacin was measured at 446 nm (emission) and at 328 nm (excitation). A linear relationship between concentration of ciprofloxacin and fluorescence intensity was found in the range of 0.04 μg/mL–6.0 μg/mL with a correlation coefficient of 0.9946. The limit of detection (LOD) and limit of quantification (LOQ) were calculated and found to be 3.87 × 10−5 and 1.29 × 10−4 μg/mL respectively. The effect of common excipients and co-administered drugs were also investigated and the method was found free of interferences. The method was successfully applied for the determination of ciprofloxacin in pharmaceutical preparations and human plasma with percentage recoveries of 97.08 % to 99.32 % and 95.00 % to 101.25 % respectively.

Innovative Configurations of Sample Preparation Techniques Applied in Bioanalytical Chemistry: A Review

Background:

Recently, in all fields of analytical chemistry, increased attention has been paid to extraction procedures and instrumental methods, which are easily scalable and are able to automate in order to improve the “high-throughput” capability.

Introduction:

The main goal of these applications relates to an improvement of the precision in the quantitative analysis, reduction of different sources of errors, decrease the analysis time and, in general, improve the analytical performances. Often these points can be in contrast to each other, not allowing to achieve the expected result but forcing a compromise between the objectives of the method and the analytical performance.

Methods:

In this review, following the evolution of the (micro)extraction procedures and instrument configurations, the recent procedures used in bioanalytical chemistry are critically evaluated. The aim of this paper is providing an overview of the approaches available in order to perform on-line coupling of various extraction techniques with chromatographic methods for the analysis of different compounds in various samples. Furthermore, a comparison between off-line and on-line systems, advantages of on-line systems applied on major extractive techniques and future perspectives are described.

Result:

The extraction methods suitable for on-line coupling covered in this review are: liquid-liquid extraction (LLE), solid phase extraction (SPE), solid phase microextraction (SPME), dispersive liquid- liquid microextraction (DLLME), microextraction by packed sorbent (MEPS), supercritical fluid extraction (SFE) and fabric phase sorptive extraction (FPSE).

Conclusion:

An overview of the micro-extraction techniques mentioned above was provided, making a comparison between them and focusing attention on future perspectives.

Novel MIPs-Parabens based SPE Stationary Phases Characterization and Application

In this work, the synthesis, characterization, and application of novel parabens imprinted polymers as highly selective solid-phase extraction (SPE) sorbents have been reported. The imprinted polymers were created using sol–gel molecular imprinting process. All the seven parabens were considered herein in order to check the phase selectivity. By means of a validated HPLC-photodiode array detector (PDA) method all seven parabens were resolved in a single chromatographic run of 25 min. These SPE sorbents, in-house packed in SPE empty cartridges, were first characterized in terms of extraction capability, breakthrough volume, retention volume, hold-up volume, number of theoretical plates, and retention factor. Finally, the device was applied to a real urine sample to check the method feasibility on a very complex matrix. The new paraben imprinted SPE sorbents, not yet present in the literature, potentially encourage the development of novel molecularly imprinted polymers (MIPs) to enhance the extraction efficiency, and consequently the overall analytical performances, when the trace quantification is required.

Porphyrin-functionalized graphene oxide sheets: An efficient nanomaterial for micro solid phase extraction of non-steroidal anti-inflammatory drugs from urine samples

In this work, porphyrin-functionalized graphene oxide nanosheets (GO@meso-tetrakis(4-hydroxyphenyl)porphyrin) were synthesized and employed as the sorbent. Porphyrins owing to their unique structures and tunable terminal functional groups are expected to be promising media for extraction of the desired analytes. Also, GO with a high specific surface area has exhibited good potential for the extraction purposes. Inspired by these intriguing properties, the combination of GO and porphyrin can benefit both of these amazing features. The synthesized sorbent was utilized for micro solid phase extraction of non-steroidal anti-inflammatory drugs followed by HPLC-UV. Optimization of the experimental factors including sorbent amount, sample pH, sample and eluent flowrates, eluent volume, and the number of desorption cycles were performed with the aid of central composite design. Under the optimal conditions, the calibration curves were linear within the range of 2.0-600 ng mL^-1 and limits of detection were found between 0.5-2.0 ng mL^-1. The preconcentration factors and absolute recoveries were obtained in the range of 4.80-9.79 and 29%-59%, respectively. The matrix effect for the urine samples varied between 81.9%-91.6% at two concentrations of 50 and 300 ng mL^-1, respectively. Intra- and inter-day RSD% (n = 3) of the spiked urine samples at three level concentrations of 25, 100, and 300 ng mL^-1 were less than 10%. The relative recoveries of the urine samples were calculated in the range of 85.2-98.6%. Eventually, the method exhibits proper sensitivity, excellent repeatability, high reusability, and acceptable precision and accuracy.

Comparison between Exhaustive and Equilibrium Extraction Using Different SPE Sorbents and Sol-Gel Carbowax 20M Coated FPSE Media

This paper reports the performance comparison between the exhaustive and equilibrium extraction using classical Avantor C18 solid phase extraction (SPE) sorbent, hydrophilic-lipophilic balance (HLB) SPE sorbent, Sep-Pak C18 SPE sorbent, novel sol-gel Carbowax 20M (sol-gel CW 20M) SPE sorbent, and sol-gel CW 20M coated fabric phase sorptive extraction (FPSE) media for the simultaneous extraction and analysis of three inflammatory bowel disease (IBD) drugs that possess logP values (polarity) ranging from 1.66 for cortisone, 2.30 for ciprofloxacin, and 2.92 for sulfasalazine. Both the commercial SPE phases and in-house synthesized sol-gel CW 20M SPE phases were loaded in SPE cartridges and the extractions were carried out under an exhaustive extraction mode. FPSE was carried out under an equilibrium extraction mode. The drug compounds were resolved using a Luna C18 column (250 mm × 4.6 mm; 5 m particle size) in gradient elution mode within 20 min and the method was validated in compliance with international guidelines for the bioanalytical method validation. Novel in-house synthesized and loaded sol-gel CW 20M SPE sorbent cartridges were characterized in terms of their extraction capability, breakthrough volume, retention volume, hold-up volume, number of the theoretical plate, and the retention factor.

Current trends on microextraction by packed sorbent – fundamentals, application fields, innovative improvements and future applications

MEPS, the acronym of microextraction by packed sorbent, is a simple, fast and user- and environmentally-friendly miniaturization of the popular solid-phase extraction technique (SPE).

Gold(I)-Catalyzed and H2O-Mediated Carbene Cascade Reaction of Propargyl Diazoacetates: Furan Synthesis and Mechanistic Insights

A novel gold-catalyzed water-mediated carbene cascade reaction of propargyl diazoacetates has been developed. Mechanistic investigation indicates that this reaction is initiated by gold-catalyzed gold-carbene formation followed by an unprecedented 6- endo-dig carbocyclization with tethered alkyne through an oxonium ylide intermediate, terminated by a β-H elimination/protodeauration process to give the aromatized furan products in good to high yields with broad substrate generality. Notably, the proposed gold-carbene intermediates are verified by interception experiments.

Fast quantification of fluoroquinolones in environmental water samples using molecularly imprinted polymers coupled with internal extractive electrospray ionization mass spectrometry

A simple, fast and high-sensitivity method for quantification of fluoroquinolones in environmental water samples using MIPs-iEESI-MS.

Analysis of imidazoles and triazoles in biological samples after MicroExtraction by packed sorbent

This paper reports the MEPS-HPLC-DAD method for the simultaneous determination of 12 azole drugs (bifonazole, butoconazole, clotrimazole, econazole, itraconazole, ketoconazole, miconazole, posaconazole, ravuconazole, terconazole, tioconazole and voriconazole) administered to treat different systemic and topical fungal infections, in biological samples. Azole drugs separation was performed in 36 min. The analytical method was validated in the ranges as follows: 0.02–5 μg mL⁻¹ for ravuconazole; 0.2–5 μg mL⁻¹ for terconazole; 0.05–5 μg mL⁻¹ for the other compounds. Human plasma and urine were used as biological samples during the analysis, while benzyl-4-hydroxybenzoate was used as an internal standard. The precision (RSD%) and trueness (Bias%) values fulfill with International Guidelines requirements. To the best of our knowledge, this is the first HPLC-DAD procedure coupled to MEPS, which provides the simultaneous analysis of 12 azole drugs, available in the market, in human plasma and urine. Moreover, the method was successfully applied for the quantitative determination of two model drugs (itraconazole and miconazole) after oral administration in real samples.