Ionic liquid-based single-drop liquid-phase microextraction combined with high-performance liquid chromatography for the determination of sulfonamides in environmental water

Nano-sized magnetic molecularly imprinted polymer solid-phase microextraction for highly selective recognition and enrichment of sulfamethoxazole from spiked water samples

This research, described ultrasound-assisted dispersive magnetic solid-phase microextraction, which is efficient for the enrichment and determination of sulfamethoxazole, based on magnetic molecularly imprinted polymer (USA-DMSPME-MIP). Meanwhile, the initial characterization of Fe3O4-MIP was completed by conventional methods and well-known protocols to obtain recognition and adsorbing performance at pre-specified optimum conditions. Fe3O4-MIP exhibited information regarding its selective recognition pattern towards sulfamethoxazole. The USA-DMSPME-MIP parameters were optimized by response surface methodology, and based on optimum conditions, this efficient method for the extraction and enrichment of sulfamethoxazole from spiked water samples and quantification by HPLC-UV was used. The enhanced technique indicates the limit of detection is 2 ng mL-1 for sulfamethoxazole, along with excellent linear range with coefficients of determination >0.99 and good recoveries for spiked water samples (94.2 and 98.2 %) with RSDs less than 3.5 %.

Preparation of COPs Mixed Matrix Membrane for Sensitive Determination of Six Sulfonamides in Human Urine

In this study, TpDMB-COPs, a specific class of covalent organic polymers (COPs), was synthesized using Schiff-base chemistry and incorporated into a polyvinylidene fluoride (PVDF) polymer for the first time to prepare COPs mixed matrix membranes (TpDMB-COPs-MMM). A membrane solid-phase extraction (ME) method based on the TpDMB-COPs-MMM was developed to extract trace levels of six sulfonamides from human urine identified by high-performance liquid chromatography (HPLC). The key factors affecting the extraction efficiency were investigated. Under the optimum conditions, the proposed method demonstrated an excellent linear relationship in the range of 3.5-25 ng/mL (r2 ≥ 0.9991), with the low limits of detection (LOD) between 1.25 ng/mL and 2.50 ng/mL and the limit of quantification (LOQ) between 3.50 ng/mL and 7.00 ng/mL. Intra-day and inter-day accuracies were below 5.0%. The method's accuracy was assessed by recovery experiments using human urine spiked at three levels (7-14 ng/mL, 10-15 ng/mL, and 16-20 ng/mL). The recoveries ranged from 87.4 to 112.2% with relative standard deviations (RSD) ≤ 8.7%, confirming the applicability of the proposed method. The developed ME method based on TpDMB-COPs-MMM offered advantages, including simple operation, superior extraction affinity, excellent recycling performance, and easy removal and separation from the solution. The prepared TpDMB-COPs-MMM was demonstrated to be a promising adsorbent for ME in the pre-concentration of trace organic compounds from complex matrices, expanding the application of COPs and providing references for other porous materials in sample pre-treatment.

Preconcentration of sulphonamides in bovine milk by the cloud point extraction method using smartphone-based digital images

Sulphonamides are a group of synthetic antibiotics used specially in veterinary medicine. Among the procedures employed in the sample preparation for sulphonamide determination are liquid-liquid extraction (LLE) and solid-phase extraction (SPE) that use large volumes of organic solvents. Hence, a clean procedure was developed based on preconcentration and cloud point extraction (CPE) without using organic solvents to quantify total sulphonamides in bovine milk. The procedure was optimized as follows: 2 mL of pre-cleaned milk sample, 2 mL of reagent solution and 1 mL of Triton X-114 7% (m/v) were added to a tube, heated in a water bath at 40 °C for 10 minutes and centrifuged at 2950 rcf for 20 minutes. Digital image acquisition was employed directly at the tube without removing the supernatant/aqueous phase. The linear response was observed between 10 and 400 μg L^-1 of total sulphonamides and described by the following equation: S = 2.50 + 0.0514C (μg L^-1) and R = 0.999. The LOD and the CV (n = 11) were estimated to be 10 μg L^-1 and 1.3%, respectively. The main interferents present at their usual concentrations in the sample did not interfere with the results. Spike and recovery tests of total sulphonamides were carried out in UHT and pasteurized milk with recovery values between 73 and 106% and the results obtained for this kind of sample were in agreement with those achieved by a high performance liquid chromatography (HPLC) procedure at the 95% confidence level. The analytical procedure presents an adequate sensitivity to determine total sulphonamides in bovine milk and does not require organic solvents, being aligned to the principles of green chemistry.

The electrospun polyacrylonitrile/covalent organic framework nanofibers for efficient enrichment of trace sulfonamides residues in food samples

In this work, the electrospun polyacrylonitrile/covalent organic frameworks Tp-BD nanofibers (PAN/Tp-BD) were synthesized and applied as an adsorbent for thin film microextraction (TFME) of seven sulfonamides in animal derived food samples. The morphology, structure, porosity, and stability of the prepared nanofibers were investigated. The PAN/Tp-BD nanofibers exhibited good chemical stability, high flexibility, porous fibrous structure, and excellent extraction efficiency. Based on the PAN/Tp-BD nanofibers as the adsorbent, a thin film microextraction-high performance liquid chromatography (TFME-HPLC) method for the determination of seven sulfonamides (SAs) in food samples was developed. Under the optimal conditions, the TFME-HPLC exhibited the low limit of detection (0.10-0.18 ng·mL^-1), the low limit of quantitation (0.33-0.60 ng·mL^-1), the wide linear range (0.5-50 ng·mL^-1) with correlation coefficients between 0.994 and 0.998, and good enrichment factors between 39.7 to 170.1 towards 20 ng/mL SAs solution. The relative standard deviation (RSD) was lower than 11% in the interday and intraday analysis. Furthermore, the applicability of PAN/Tp-BD nanofibers was demonstrated for measuring trace SAs residues in the spiked food samples with recoveries ranging from 85.3% to 115.2%. The results demonstrated that the PAN/Tp-BD nanofibers have great potential for the efficient extraction of sulfonamides from complex food samples.

Single-drop microextraction technique for the determination of antibiotics in environmental water

Growing concerns related to antibiotic residues in environmental water have encouraged the development of rapid, sensitive, and accurate analytical methods. Single-drop microextraction has been recognized as an efficient approach for the isolation and preconcentration of several analytes from a complex sample matrix. Thus, single-drop microextraction techniques are cost-effective and less harmful to the environment, subscribing to green analytical chemistry principles. Herein, an overview and the current advances in single-drop microextraction for the determination of antibiotics in environmental water are presented were included. In particular, two main approaches used to perform single-drop microextraction (direct immersion-single-drop microextraction and headspace-single-drop microextraction) are reviewed. Furthermore, the impressive analytical features and future perspectives of single-drop microextraction are discussed in this review. This article is protected by copyright. All rights reserved.

Recent developments in sample preparation techniques combined with high-performance liquid chromatography: A critical review

This review article compares and contrasts sample preparation techniques coupled with high-performance liquid chromatography (HPLC) and describes applications developed in biomedical, forensics, and environmental/industrial hygiene in the last two decades. The proper sample preparation technique can offer valued data for a targeted application when coupled to HPLC and a suitable detector. Improvements in sample preparation techniques in the last two decades have resulted in efficient extraction, cleanup, and preconcentration in a single step, thus providing a pathway to tackle complex matrix applications. Applications such as biological therapeutics, proteomics, lipidomics, metabolomics, environmental/industrial hygiene, forensics, glycan cleanup, etc., have been significantly enhanced due to improved sample preparation techniques. This review looks at the early sample preparation techniques. Further, it describes eight sample preparation technique coupled to HPLC that has gained prominence in the last two decades. They are (1) solid-phase extraction (SPE), (2) liquid-liquid extraction (LLE), (3) gel permeation chromatography (GPC), (4) Quick Easy Cheap Effective Rugged, Safe (QuEChERS), (5) solid-phase microextraction (SPME), (6) ultrasonic-assisted solvent extraction (UASE), and (7) microwave-assisted solvent extraction (MWASE). SPE, LLE, GPC, QuEChERS, and SPME can be used offline and online with HPLC. UASE and MWASE can be used offline with HPLC but have also been combined with the online automated techniques of SPE, LLE, GPC, or QuEChERS for targeted analysis. Three application areas of biomedical, forensics, and environmental/industrial hygiene are reviewed for the eight sample preparation techniques. Three hundred and twenty references on the eight sample preparation techniques published over the last two decades (2001-2021) are provided. Other older references were included to illustrate the historical development of sample preparation techniques.

A selective and efficient microfluidic method-based liquid phase microextraction for the determination of sulfonamides in urine samples

Liquid phase microextraction (LPME) into a microfluidic has undergone great advances focused on downscaled and miniaturized devices. In this work, a microfluidic device was developed for the extraction of sulfonamides in order to accelerate the mass transfer and passive diffusion of the analytes from the donor phase to the acceptor phase. The subsequent analysis was carried out by high performance liquid chromatography with UV-DAD (HPLC-DAD). Several parameters affecting the extraction efficiency of the method such as the supported liquid membrane, composition of donor and acceptor phase and flow rate were investigated and optimized. Tributyl phosphate was found to be a good supported liquid membrane which confers not only great affinity for analytes but also long-term stability, allowing more than 20 consecutive extractions without carry over effect. Under optimum conditions, extraction efficiencies were over 96 % for all sulfonamides after 10 minutes extraction and only 10 µL of sample was required. Relative standard deviation was between 3-5 % for all compounds. Method detection limits were 45, 57, 54 and 33 ng mL^-1 for sulfadiazine (SDI), sulfamerazine (SMR), sulfamethazine (SMT) and sulfamethoxazole (SMX), respectively. Quantitation limits were 0.15, 0.19, 0.18 and 0.11 µg mL^-1 for SDI, SMR, SMT SMX, respectively. The proposed microfluidic device was successfully applied for the determination of sulfonamides in urine samples with extraction efficiencies within the range of 86-106 %. The proposed method improves the procedures proposed to date for the determination of sulfonamides in terms of efficiency, reduction of the sample volume and extraction time.

Double salting-out effect assisted heat-shrinkable tubing liquid phase microextraction followed by high performance liquid chromatography for determination of flavonoids in human plasma

This paper proposed a double salting-out effect assisted heat-shrinkable tubing liquid phase microextraction (LPME). In the study, a low price and handy heat-shrinkable tubing was used as carrier of extraction solvent and salt film, which was placed in sample solution containing certain concentration of salt for concentrating and enriching flavonoids from human plasma. Through the double salting-out effect in different regions, this microextraction method has a good present to enhance the extraction efficiency and enrichment factors of the target analytes. Several key parameters affecting the extraction efficiency were investigated, including the type of extraction solvent, the occurring region of salting-out effect, salt concentration, pH of sample phase, stirring rate, extraction time, and volume of sample phase. Also, the mechanism of the procedure was described. Under the optimum conditions, excellent linearities with r≥ 0.9912 were obtained, the limits of detection were 2.5-150 ng/mL, the average recoveries ranged from 90.3% to 111.2%. In the new procedure, the low-cost and stable heat-shrinkable tubing was first used as carrier in LPME, combined with high performance liquid chromatography (HPLC), has been successfully applied for the determination of the trace-level target analytes in human plasma.

Ionic Liquid-based Hollow Fiber Liquid–Liquid–Liquid Microextraction Combined with Capillary Electrophoresis for the Determination of Sulfonamides in Aquaculture Waters

Ionic liquid-based hollow-fiber liquid–liquid–liquid microextraction (IL-HF-LLLME) coupled to capillary electrophoresis (CE) has been developed for the determination of six sulfonamides (SAs) in aquaculture waters. A series of extraction parameters was optimized to enhance the extraction efficiency, which included type and pore size of hollow fiber, type and composition of extraction solvent, pH value of donor phase, the concentration of acceptor phase and the mass ratio of donor phase to acceptor phase along with extraction temperature and time. Under optimal conditions, the IL-HF-LLLME-CE method provided a wide liner range for six SAs from 2 to 1,000 μg L−1 (r2 ≥ 0.9995), the limits of the detection from 0.25 to 0.48 and the enrichment factors from 122 to 230, respectively. Relative standard deviations for intra- and interday precision were 1.4–5.3% and 1.8–7.5% (n = 5), respectively. The proposed method was successfully applied for the determination of trace-level SAs in seven real-world aquaculture water samples with good recoveries (80.4–100.7%). Also, sulfamerazine and sulfamethoxazole were detected at the level of 0.52–1.60 μg L−1 in two water samples. Due to its good sensitivity, simple operation, short analysis time and eco-friendliness, the developed method has a great application potential in analysis of trace SA residues in aquaculture waters.

Robotic-assisted dynamic large drop microextraction

By proper design of an innovative extraction device, a lab-made multipurpose autosampler was exploited in the automated performance of the dynamic large drops based microextraction. The pluses of this new analytical strategy were demonstrated in the determination of sulfonamides and fluoroquinolones in surface water samples, by direct immersion single drop microextraction (SDME) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis. Operational autosampler features and critical experimental factors influencing SDME, including the extraction mode (static or dynamic), extraction, stirring rate, salt addition, drop size, number of cycles and drop exposition time, were comprehensively investigated using both univariate and multivariate optimization. The lab-made autosampler allowed to performance challenging dynamic and static large drop based SDMEs in an automated and effortless way and with minimal requirements of hardware and software. Large stable drops provided high surface area, enhancing the phase ratio and in consequence increasing the analytes uptake. The best extraction efficiencies were obtained as a result of the synergic interaction between the use of large drops and the automated dynamic mode of extraction. The developed method proved to be a reliable, sensitive, and robust analytical tool, with intraday RSDs ranging between 4.0 and 7.6% (n = 6), and interday RSDs between 4.8 and 9.3% (n = 6), and, LOD and LOQ in the range of 15-50 and 35-100 ng L^-1, respectively.

Microwave-assisted liquid-liquid microextraction based on solidification of ionic liquid for the determination of sulfonamides in environmental water samples

An easy, quick, and green method, microwave-assisted liquid-liquid microextraction based on solidification of ionic liquid, was first developed and applied to the extraction of sulfonamides in environmental water samples. 1-Ethy-3-methylimidazolium hexafluorophosphate, which is a solid-state ionic liquid at room temperature, was used as extraction solvent in the present method. After microwave irradiation for 90 s, the solid-state ionic liquid was melted into liquid phase and used to finish the extraction of the analytes. The ionic liquid and sample matrix can be separated by freezing and centrifuging. Several experimental parameters, including amount of extraction solvent, microwave power and irradiation time, pH of sample solution, and ionic strength, were investigated and optimized. Under the optimum experimental conditions, good linearity was observed in the range of 2.00-400.00 μg/L with the correlation coefficients ranging from 0.9995 to 0.9999. The limits of detection for sulfathiazole, sulfachlorpyridazine, sulfamethoxazole, and sulfaphenazole were 0.39, 0.33, 0.62, and 0.85 μg/L, respectively. When the present method was applied to the analysis of environmental water samples, the recoveries of the analytes ranged from 75.09 to 115.78% and relative standard deviations were lower than 11.89%.

Recent advances in sample preparation techniques and methods of sulfonamides detection - A review

Sulfonamides (SAs) have been the most widely used antimicrobial drugs for more than 70 years, and their residues in foodstuffs and environmental samples pose serious health hazards. For this reason, sensitive and specific methods for the quantification of these compounds in numerous matrices have been developed. This review intends to provide an updated overview of the recent trends over the past five years in sample preparation techniques and methods for detecting SAs. Examples of the sample preparation techniques, including liquid-liquid and solid-phase extraction, dispersive liquid-liquid microextraction and QuEChERS, are given. Different methods of detecting the SAs present in food and feed and in environmental, pharmaceutical and biological samples are discussed.

Ionic liquid-salt aqueous two-phase extraction based on salting-out coupled with high-performance liquid chromatography for the determination of sulfonamides in water and food

Ionic liquid-salt aqueous two-phase extraction coupled with high-performance liquid chromatography with ultraviolet detection was developed for the determination of sulfonamides in water and food samples. In the procedure, the analytes were extracted from the aqueous samples into the ionic liquid top phase in one step. Three sulfonamides, sulfamerazine, sulfamethoxazole, and sulfamethizole were selected here as model compounds for developing and evaluating the method. The effects of various experimental parameters in extraction step were studied using two optimization methods, one variable at a time and Box-Behnken design. The results showed that the amount of sulfonamides did not have effect on the extraction efficiency. Therefore, a three-level Box-Behnken experimental design with three factors, which combined the response surface modeling, was used to optimize sulfonamides extraction. Under the most favorable extraction parameters, the detection limits (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target compounds were achieved within the range of 0.15-0.3 ng/mL and 0.5-1.0 ng/mL from spiked samples, respectively, which are lower than or comparable with other reported approaches applied to the determination of the same compounds. Finally, the proposed method was successfully applied to the determination of sulfonamide compounds in different water and food samples and satisfactory recoveries of spiked target compounds in real samples were obtained.