Determination Of Sulfonamides Research Articles

3D-integrated membrane protected micro-solid-phase extraction of sulfonamides in food samples: An innovative approach

A sensitive, eco-friendly and cost-effective 3D-integrated membrane-protected micro solid-phase extraction (3D-MP-µ-SPE) method was developed for the determination of sulfonamides (SAs) in water, milk and fish samples prior to high-performance liquid chromatography with diode array detection (HPLC-DAD). Innovatively, a 3D-printed filter holder was designed and printed by a stereolithography (SLA) printer to securely hold the µ-SPE device for extracting four SAs-: sulfadiazine (SDZ), sulfachloropyridazine (SCP), sulfamethoxazole (SMX) and sulfadimethoxine (SDM). The µ-SPE device was prepared using a nylon filter mesh, and 60 mg of Strata X was placed inside and heat sealed. Optimization parameters of the 3D-MP-µ-SPE method were studied including − type of preconditioning solvent, dosage amount, effect of drying, sample volume, number of extraction and desorption flows, type and volume of desorption solvent, and pH. Under the optimized conditions, good linearity was observed between 1 and 500 µg L−1 with an R2 of 0.9931 to 0.9994 for all the SAs. The limit of detection and quantification ranged between 0.16–0.54 µg L−1 and 0.49–1.65 µg L−1 respectively. The method demonstrated good extraction recovery (84.2 % to 114.5 %) for real sample analysis, with a relative standard deviation of less than 5.9 %. Moreover, the Analytical GREEnness (AGREE) score of 0.66 indicates the environmental friendliness of the proposed method. In conclusion, this 3D-MP-µ-SPE method offers a sustainable and efficient solution for SAs determination, with robust performance and minimal environmental impact.

Electrospun nanofiber composite based on bimetallic metal–organic framework/halloysite nanotubes/deep eutectic solvents/molecularly imprinted polymers for thin film microextraction of sulfonamides in milk, eggs and chicken meat by HPLC analysis

Herein, electrospun nanofibers based on bimetallic metal–organic framework@ functionalized halloysite/deep eutectic solvents/molecularly imprinted polymers was synthesized as new solid phase extractant for thin film microextraction of sulfacetamide, sulfamethoxazole, sulfamethazine and silversulfadiazine by HPLC-UV analysis. After synthesizing new phase through electrospinning nanofibers and thin film fabrication, we effectively leverage the synergistic properties of these materials within the composite structure. The resultant thin film nanocomposite, which integrates molecularly imprinted nanofibers, highlights the presence of inorganic nanotubes called halloysite, functionalized with a deep eutectic solvent and bimetallic metal–organic frameworks. Characterization of synthesized thin films were successfully characterized for structural, morphological, and surface analysis using infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). In this study, a syringe design was employed for the microextraction of sulfonamides (SAs) using thin film microextraction, which is carried out in two stages: adsorption and desorption, both within the syringe. The effects of several experimental conditions on desorption stage, including desorption parameters including pH, desorption solvent type, and ultrasonication time were studied by the single factor at a time. A Box-Behnken design (BBD) was applied to optimize the significant variables to obtain the optimum extraction conditions. The detection limit of the method was 0.003 µg/L and also the limit of quantification method was in the range of 0.01 µg/L. These results demonstrate the presented thin film microextraction method can serve as a good candidate for the microextraction and determination of sulfonamides in food samples like milk, eggs and chicken meat.

Introduction of an electrospun nanofibrous membrane incorporated by metal-organic framework-199 (MOF-199) with Lewis acid property for efficient extraction of sulfonamides in on-chip electromembrane extraction

In this study, a new supporting polymeric membrane having Lewis acid nature was introduced for immobilizing organic solvent in on-chip electromembrane extraction (on-chip EME). For this aim, a polymeric nanofibrous membrane incorporated by a copper based metal-organic framework (MOF-199), with coordinatively unsaturated metal sites and Lewis acid property, was prepared by electrospinning a mixture of polycaprolactone (PCL) and MOF-199. Based on the field emission scanning electron microscopy images, the obtained polymeric membrane consisted of intertwined nanofibers having empty space between the fibers which could provide a suitable place for immobilizing the organic solvent. To demonstrate remarkable extractability of the proposed membrane (PCL/MOF-199 nanofibers) via executing Lewis acid-base interactions, three sulfonamide drugs was selected as anionic polar analytes with Lewis base feature. The parameters affecting the extraction efficiency of the method were optimized through the experimental design method using the orthogonal and rotatable central composite design (CCD). Under optimum conditions, the extraction recoveries ranging from 35.5 to 71.2 %, the relative standard deviations (RSD%) less than 6.45 %, and the detection limits in the range of 0.2–0.5 μg L−1 were achieved. The comparison of the extraction efficiency of the on-chip EME method using the electrospun PCL/MOF-199 nanofibers and PCL nanofibers membranes indicated that the proposed membrane was more efficient for extraction of sulfonamides because of the significant Lewis acid-base interactions of sulfonamides with copper uncoordinated open sites in MOF-199. Finally, the performance of the proposed method for extraction and determination of sulfonamides in three real samples was assayed.

Determination of sulfonamides in muscle: a metrological tool for food safety

Sulfonamides represent a wide class of synthetic drugs commonly used in veterinary therapy for the treatment of several bacterial and protozoan infections in cattle, swine and poultry. The use of these drugs in farming can lead to the possibility of having their residues in animal products intended for human consumption. Consequently, to ensure high consumer protection, for sulfonamides European Union (EU) set a Maximum Residue Limit (MRL) equal to 100 µg/kg, either as a single molecule or as a sum of all detected compounds within the class). Official laboratories are directly involved in the execution or residue plans by developing, validating and then applying analytical methods for the measurement of drug residues. Accordingly, official laboratories should update their procedures following the evolution of required drugs and MRLs. A multiclass method previously developed and validated for the determination in animal muscle of ten classes of antibiotics was adjusted to comply with the current European requirements which establish the minimum set of sulfonamides to be determined. Therefore, eight new sulfonamides were added assessing method performance characteristics according to European Regulation (EU) 808/2021.

Simultaneous determination of sulfonamides, trimethoprim, amoxicillin and tylosin in medicated feed by high performance liquid chromatography with mass spectrometry.

The article presents a rapid and simple analytical procedure for determination of four sulfonamides (sulfadiazine, sulfamerazine, sulfamethazine and sulfamethoxazole), trimethoprim, tylosin and amoxicillin in animal medicated feed. Eighteen medicated feed samples were analysed for active substances. The analytical protocol used a mixture of acetonitrile and 0.05 M phosphoric buffer, pH 4.5 for the extraction of seven antibacterial substances. After extraction, the samples were diluted in Milli-Q water and analysed by liquid chromatography with mass spectrometry. The developed procedure was subjected to validation in terms of linearity, selectivity, limits of quantification and determination, repeatability, reproducibility and uncertainty. The validation of the method was carried out in accordance with the criteria set out in Commission Implementing Regulation (EU) 2021/808 and ICH guidelines. This method provided average recoveries of 90.8 to 104.5% with coefficients of variation for repeatability and reproducibility in the ranges of 3.2-6.9% and 5.2-8.3%, respectively for all analysed antibacterial substances. The limit of detection and limit of quantification for all seven analytes ranged from 5.4 mg/kg to 48.3 mg/kg and from 10.4 mg/kg to 119.3 mg/kg, respectively. The uncertainty of the method depending on the compound varied from 14.0% to 24.0%. The validated method was successfully applied to the 18 medicated feeds. The developed method can be successfully used to routinely control the content and homogeneity of seven antibacterial substances in medicated feed.

Simple, fast and eco-friendly micro-solid phase extraction based on thiol and ionic liquid bi-functional nanofibers membrane for the determination of sulfonamides in environmental water

BackgroundSulfonamides (SAs) are a class of synthetic antibacterial agents that are diffusely used in the medical industry and animal husbandry. Their prevalence in the influents and effluents of water treatment plants, as well as in rivers and groundwater, has provoked worldwide concern. Monitoring SAs in environmental water is of great significance for public health. However, most of the available detection techniques for SAs are cumbersome and time-consuming. With the increasing number of actual samples, simple, fast and environmentally friendly analytical methods are always in demand. ResultsHerein, we describe a highly efficient micro-solid phase extraction (μ-SPE) sample preparation technique based on a novel thiol and ionic liquid bi-functional nanofibers membrane (IL-SH-PAN NFsM) for multi-residue detection of sulfonamides (SAs) in water samples. By the synergistic effect of -SH and -IL, the as-prepared IL-SH-PAN NFsM demonstrated high adsorption capacity and excellent selectivity for SAs. The water samples can be directly used for μ-SPE without pH and ionic strength adjustment, and the eluent can be directly collected for HPLC-MS/MS analysis. Compared with other methods reported in the literature, this method required much shorter extraction time (2 min for a batch), much less amount of adsorbent (4.0 mg) and organic solvent (0.5 mL), while providing much higher sensitivity (1.4–3.9 ng L−1), and fine recoveries (88.8%–117.7%) with relative standard deviations less than 4.26%. Significance and noveltyA bi-functional nanofibers membrane was prepared for efficient extraction of SAs. The adsorbent exhibited superior adsorption performance and excellent selectivity. The underlying interaction mechanisms derived from -SH and -IL were proposed, which provide a new idea for preparing versatile adsorbents. Rapid, efficient and sensitive detection of SAs in water was achieved. The novel sample preparation technique can be expected as an efficient method for routine trace SAs residue monitoring in various water samples.

A supramolecular solvent-based vortex-assisted direct microextraction of sulfonamides in sediment samples

A new supramolecular solvent (SUPRAS)-based vortex-assisted microextraction combined with high performance liquid chromatography was developed for simultaneous extraction and determination of sulfonamides (SAs) in lake sediment samples. A novel SUPRAS formation in aqueous solution containing heptafluorobutanol (HeFB) and citronellol (CTL) is proposed. Environmentally friendly and non-toxic CTL acted as amphiphile, and HeFB was the coacervation agent and density-regulating agent for the SUPRAS preparation. The main driving forces for the SUPRAS are hydrogen bonding and hydrophobic interactions of HeFB with CTL. Parameters including the type and content of coacervation agent, content of CTL, volume of SUPRAS and vortex time were thoroughly investigated and optimized. The optimized conditions were evaluated by SUPRAS comprising 10 % HeFB and 4 % CTL. The volume of SUPRAS was 400 µL and the extraction time was 3 min. The prepared SUPRAS can effectively exclude some interferants and extract SAs from sediment samples with high extraction efficiency. Under the optimized conditions, low limits of detection (30–60 ng g−1) and limits of quantification (100–200 ng g−1), wide linear range (0.2–700 μg g-1, R2 ≥ 0.9974), high extraction recoveries (99.5–104.2 %) and good precision (relative standard deviations were 0.8 %-6.3 %) were obtained. Finally, the applicability of the developed method was evaluated by determining SAs in lake sediment samples. Sulfamethazine was detected at 1.59–1.77 μg g−1 for the three sediment samples. The novel HeFB-CTL SUPRAS can be applied to extract SAs from environmental sediment samples.

Paper-based analytical device for sensitive colorimetric determination of sulfonamides in pharmaceutical samples

Sulfa drugs are frequently used to treat infections, particularly in antibiotic resistant people. There are several techniques available to determine sulfa drugs, however, they are laborious operation, reagent consumption, expensive, and need specialized types of equipment. Here, a new, very simple and inexpensive paper-based analytical device described for the determination of five sulfa drugs: sulfacetamide, sulfadiazine, sulfamerazine, sulfamethoxazole, and sulfathiazole in pharmaceutical preparations. The method is a one-step reaction, based on the colorimetric reaction between acid-hydrolyzed sulfa drugs and 4-dimethylaminobenzaldehyde. Using a smartphone, the RGB value of color intensity was used as an analytical signal. The paper-based device displayed linear ranges of 0.10–5.00 µg mL−1, linear correlations ranging from 0.9903 to 0.9972, limits of detection 0.0030 to 0.0082 µg mL−1, and RSD of ≤0.258 under optimal conditions. The suggested approach was applied for determining five sulfa drugs in pharmaceutical formulations. This approach is appropriate for pharmaceutical applications since it is inexpensive, simple to utilize, sensitive, and selective.

Dispersive liquid-liquid microextraction based on deep eutectic solvent doped with hydroxyethyl-β-cyclodextrin for the determination of sulfonamides in environmental waters

A novel method was pioneered for the enrichment of six sulfonamides (SAs) in environmental waters, i.e., vortex-assisted dispersive liquid–liquid microextraction based on hydroxyethyl-β-cyclodextrin doped deep eutectic solvent (VA-DLLME-HCDDES). A hydrophobic deep eutectic solvent (HDES) was synthesized and used as an extractant based on two reaction precursors (benzyltriethylammonium chloride and thymol), and the doping of hydroxyethyl-β-cyclodextrin (HE-β-CD). The addition of HE-β-CD to the HDES greatly enhanced the enrichment factor for SAs by 21.6%. For the first time, the HE-β-CD doped HDES was demonstrated to be a supramolecular ternary DES (SUPRATDES). A multivariant methodology of Plackett-Burman design followed by central composite design was employed to screen and optimize several influencing factors in the VA-DLLME-HCDDES procedures. Under optimized conditions, the VA-DLLME-HCDDES/HPLC-PDA method showed good linear range of 1.1–500 μg L−1 (r2 > 0.9996) with the limits of detection of 0.3–1.1 μg L−1. After verification of its reliability with a certified reference standard (81267a), the newly developed method was successfully applied for the trace-level detection of SAs in environmental waters with relative recoveries of 84–112%. Overall, the prominent advantages of the proposed method are free of dispersant, easy preparation of HCDDES, environmental benignity and high extraction efficiency. Thus, the newly developed method provides a good alternative to conventional approaches for detection of SAs.

Ultrasonic assisted dispersive micro-solid phase extraction of some sulfonamide antibiotics from milk and egg samples using polymeric ionic liquid-based chitosan before HPLC analysis

In this study, simple, fast, sensitive and environmentally friendly ultrasonic assisted-dispersive micro-solid phase extraction was reported for separation and trace analysis of sulfamethizole, sulfadiazine, sulphamethoxazole, sulfachloropyridazine, sulfisoxazole and sulfadimethoxin. Sulfonamide determination was carried out by high performance liquid chromatography with diiodide array detector. Eco-friendly polymeric ionic liquid-based chitosan was used as sorbent. For the optimization of the ultrasonic assisted-dispersive micro-solid phase extraction, parameters such as sample pH, sorbent amount, extraction time, extraction temperature, salt effect, type and volume of elution solution and elution time were examined. The proposed method had wide linearity (3–1000 μg L-1, R2 ≥ 0.9982), low limit of detection (0.93–1.21 μg L-1) and low limit of quantification (3.11–4.02 μg L-1). The intra-day and inter-day repeatability were found to be 2.22–5.84% and 3.13–6.02% with 5 μg L-1 and 25 μg L-1, respectively. The suggested method was successfully implemented to extract and analyze sulfonamides in milk and egg samples.

Dispersive Liquid - Liquid Micro extraction Technique Coupled with High Performance Liquid Chromatography Diode Array Detector for the Determination of Sulfonamides in Water Samples

A dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with diode array detection (DLLME-HPLC-DAD) has been developed for the determination of 15 sulfonamides in water samples. The effects of experimental parameters on the performance of the method such as the type and volume of extraction and disperser solvents, pH of the solution, effect of salt, and centrifugation time were evaluated, and optimum conditions were established. Under these optimum conditions, linearity was found in the range of 2 - 1 000 μg L-1 with regression coefficients better than 0.9990. The limit of detection (LOD) and limit of quantification (LOQ) values were in the range of 0.6 - 7.8 μg L-1 and 1.5 - 8.3 µg L-1, respectively. Intra-day and inter-day precision ranged from 1.5 - 9.7% and from 3.1 - 9.9%, respectively. The accuracy of the method were also evaluated in samples from three different sources of water (river water, groundwater, and tap water) were found to range from 70.5 to 103.9% with %RSD values ranging from 0.5 to 9.8%, with the exception of sulfaguanidine in river water and groundwater where the percentage recovery ranged from 54.3 - 84.9% at the two higher concentration levels (100 and 400 µg L-1).Furthermore, the effect of sample matrix on the extraction of target compounds was evaluated using the relative recovery (%RR) of the samples from three different water sources relative to the ultrahigh purity (UHP) water sample spiked with target analytes, and found in the range of 70.3 - 106.1%.The proposed method was successfully applied to wastewater treatment plant samples and Sulfisoxazole (SSO) was detected in the influent samples in the range of 14.8 - 17.8 µg L-1 with corresponding %RSD, (n = 5) value of 1.6% to 1.9%.The results indicated that the proposed method is effective for the extraction and determination of the sulfonamides in water samples.

Dispersive liquid-liquid microextraction utilizing menthol-based deep eutectic solvent for simultaneous determination of sulfonamides residues in powdered milk-based infant formulas

An eco-friendly, fast, sensitive dispersive liquid–liquid microextraction (DLLME) method followed by UPLC-MS/MS was developed and validated for multi-residue determination of sulfonamides in milk-based infant and young children formulas. In this study, a natural deep eutectic solvent was synthesized using menthol and octanoic acid at a molar ratio of 1:2 for the extraction of seven sulfonamides in infant formulas. Different extraction parameters including volume of deep eutectic solvent, vortex time, centrifugation time, sample volume and pH were investigated and optimized. Under the optimum conditions, determination coefficients of ≥ 0.9993 were obtained for all studied analytes. The limits of detection ranged from 0.5 to 1.5 µg Kg−1. The extraction recoveries were in the range of 82.6–100.1% with RSDs %≤ 7.5. To investigate the applicability of the proposed method, it was applied to determination of the studied sulfonamides in thirty milk-based infant formulas of different brands. The environmental impact of the presented method was evaluated using three assessment tools namely: Eco-Scale Assessment (ESA), Green Analytical Procedure Index (GAPI) and Analytical GREEnness metric (AGREE). The characteristic performance of the developed DLLME-UPLC-MS/MS method was also compared with other reported methods.

Automated centrifugation-less milk deproteinization and homogenous liquid-liquid extraction of sulfonamides for online liquid chromatography

A novel approach to the determination of sulfonamides in milk based on the Lab-In-Syringe technique is presented. The method involves automated salting-out liquid-liquid extraction of the analytes, allowing simultaneous sample deproteination without requiring centrifugation or manual sample handling. The procedural parameters, including salt type, solvent-to-sample ratio, and salt solution volume, were studied. The extracts obtained were diluted in situ and transferred to online coupled liquid chromatography for analyte separation carried out in parallel to the subsequent extraction. In this way, a sample throughput of approximately 6 h−1 was achieved. The detection limits ranged from 25 to 32 μg L−1 using a 500 μL milk sample and spectrophotometric detection. The applicability of the developed method to sample analysis was proven by recovery values ranging from 73.2% to 94.1% (86.3% on average) for milk samples of different fat content spiked at 3 μg mL−1 level. Straightforward automation of one of the most laborious preparation steps in food analysis, i.e., deproteination, was demonstrated.

Novel and simple analytical method for simultaneous determination of sulfonamide, quinolone, tetracycline, macrolide, and chloramphenicol antibiotics in soil.

The multiclass determination of antibiotic residues in the soil is challenging because of its complex physicochemical properties. In this study, a simple analytical method was developed to simultaneously extract and determine 58 antibiotics from the soil. A novel acidity-regulated extraction-partition-concentration protocol was established for the simultaneous extraction of five classes (23 sulfonamides, 18 quinolones, five tetracyclines, eight macrolides, and four chloramphenicols) of antibiotics from the soil. Compared to traditional methods, the sample preparation efficiency was significantly improved by four times (45 min vs. 230 min) by optimizing the extraction method and omitting the time-consuming solid-phase extraction (SPE) procedure. The ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was optimized to determine the 58 antibiotics in a single run by applying positive/negative switching acquisition mode in less than 10 min with the baseline separation of sulfameter and sulfamethoxypyridazine. Suitable recoveries, ranging between 60 and 120%, were obtained for most antibiotics, with RSD <20%. The limits of quantification (LOQ) of the method were 2 μg/kg and 5 μg/kg. Thus, this study provides a simple, reliable, and economical method for accurately and rapidly determining a multiclass of antibiotics in the soil.

Production of a Natural Dihydropteroate Synthase and Development of a Signal-Amplified Pseudo-Immunoassay for the Determination of Sulfonamides in Pork.

In this study, a type of magnetic photoaffinity-labeled activity-based protein profiling probe for sulfonamide drugs was first synthesized for the purpose of capturing the natural dihydropteroate synthase of Escherichia coli by using simple incubation and magnetic separation. After characterization of its identity with LC-ESI-MS/MS, this enzyme was used as a recognition reagent to develop a direct competitive pseudo-ELISA for the determination of the residues of 40 sulfonamides in pork. Because of the use of streptavidin-horseradish peroxidase and biotinylated horseradish peroxidase as a signal-amplified system, the limits of detection for the 40 drugs were in the range of 0.001-0.016 ng/mL. Compared to the steps in a conventional assay formation, the operation steps were the same, but the sensitivities increased 32-88-fold. Furthermore, the assay performances were better than the previously reported immunoassays performances for sulfonamides. Therefore, this method could be used as a practical tool for multiscreening the trace levels of sulfonamides residues in food samples.

Preparation of boronate-modified larger mesoporous polymer microspheres with fumed silica nanoparticle and toluene as synergistic porogen for selective separation of sulfonamides

Larger mesopores can effectively reduce the diffusion resistance of target molecules in microspheres. Therefore, the photoinitiated suspension polymerization was used to fabricate a novel mesoporous polymer microsphere (MPM), in which large macropores resulted from the synergy of fumed silica nanoparticle as solid porogen and toluene as auxiliary porogen. The spherical MPM had 35.9 nm of larger mesopores and was suitable for solid phase extraction (SPE) adsorbent. To improve the selectivity and adsorption capacity, the MPM was first grafted with polyethyleneimine as amplifier, and further modified with boronic acid moieties. The successful synthesis of the boronate-modified MPM (BMPM) was confirmed by detailed characterization. Due to the combination of B-N coordination and hydrophobic (or π-π) interaction, the resultant BMPM exhibited excellent adsorption performance for nitrogen-containing sulfonamides, which was successfully fitted with Langmuir, pseudo-first-order and pseudo-second-order kinetic models, respectively. Therefore, the BMPM as SPE adsorbent was used for enrichment and separation of sulfonamides. The BMPM-based SPE process was optimized in detail, and combined with high performance liquid chromatography (HPLC) analysis for simultaneous determination of sulfonamides from real aqueous samples. The proposed BMPM-based SPE combined with HPLC strategy showed low limit of detection ranged from 0.81 to 2.50 ng mL−1. The recoveries of sulfonamides at three spiked levels ranged from 90.2% to 105.5%, 80.9% to 104.7% and 81.0% to 104.5% for tap, lake and river water, respectively. The intra- and inter-day relative standard deviations (n = 5) were no more than 5.0% and 6.7%, respectively. These results indicated that the BMPM was very promising adsorbent for selective capture of other nitrogen-containing substances and the MPM could be performed functionalization by various affinity units.

Recent Developments in the Electrochemical Determination of Sulfonamides

Background:Sulfonamides are the anti-bacterial and anti-inflammatory drugs synthesized, which are widely used as medical and veterinary antibiotics. However, the excess dosage of sulfonamides can harm human health. Drug residues in animal products also can harm human health through the food chain. The long-term consumption of animal food containing drug residues will cause some toxicity and side effects on human body functions, which will seriously threaten human health.Methods:Electroanalytical methods are attracting much attention because of their advantage over conventional methods, as they are quick, low-cost, high sensitivity, and portable. This review examines the progress made in the selective electrochemical determination of sulfonamides in the last 20 years.Results:In this review, we describe the development of electrochemical methods for sulfonamides determination. Then, we pay special attention to the detection of sulfonamides using molecular imprinting technology. The linear detection range with the limit of detection has been listed for comparison.Conclusion:Electrochemical determination of sulfonamides is a fast, simple, sensitive, and cost-effective approach. The surface modification of commercial electrodes can significantly improve the sensing performance.

Recent Developments in the Electrochemical Determination of Sulfonamides

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Recognition and Determination of Sulfonamides by Near-IR Fluorimetry Using Their Effect on the Rate of the Catalytic Oxidation of a Carbocyanine Dye by Hydrogen Peroxide

Recognition and Determination of Sulfonamides by Near-IR Fluorimetry Using Their Effect on the Rate of the Catalytic Oxidation of a Carbocyanine Dye by Hydrogen Peroxide

Determination of sulfonamides in milk and egg samples by HPLC with mesoporous polymelamine-formaldehyde as magnetic solid-phase extraction adsorbent.

In this work, magnetic mesoporous polymelamine-formaldehyde composites were synthesized via a facile Schiff base reaction. The magnetic mesoporous polymelamine-formaldehyde composites combined both the properties of mesoporous polymelamine-formaldehyde and the magnetism of NH2 -SiO2 @Fe3 O4 nanoparticles, possessing high specific surface area (150.66 m2 g-1 ) and good magnetism (24.50 emu g-1 ). The magnetic mesoporous polymelamine-formaldehyde composites were employed as magnetic adsorbent for the extraction of sulfonamides. Under optimal conditions, good linearities with correlation coefficients higher than 0.9984 were obtained between peak area and sulfonamides concentration (2-200 μg L-1 ) with limits of detection in the range of 0.33-0.58 μg L-1 . The established method was successfully applied for the determination of sulfonamides in egg and milk samples. The adsorption mechanisms demonstrated that the adsorption of magnetic mesoporous polymelamine-formaldehyde composites toward sulfonamides was a multilayer process, and adsorption kinetics followed the pseudo-second-order model.