Zinc ferrite as a magnetic sorbent for the dispersive micro solid-phase extraction of sulfonamides and their determination by HPLC

Novel phenazine-based microporous organic network for selective and sensitive determination of trace sulfonamides in milk samples

BACKGROUND

Sulfonamide (SA) residues in food of animal origin possess a potential threat to human health and environment. However, due to the polar and ionic characteristics and trace level of SAs and the complexity of food matrices, direct measurement of SAs in these samples is still very difficult. Development of efficient sample pretreatment method for sensitive and selective extraction of trace SAs is of great significance and urgently desired. Therefore, rational design and synthesizing advanced and selective extractants is quite important.

RESULTS

In this work, a novel phenazine-based microporous organic network (MON) named TEPM-DP is reasonably synthesized and employed as a packing material for selective solid phase extraction (SPE) and sensitive determination of four typical SAs in milk samples. Phenazine-based monomer with aromatic and heteroaromatic ring and numerous N atoms is chosen to construct TEPM-DP adsorbent to provide π-π, hydrogen bonding, hydrophobic, and electrostatic extraction sites for SAs. The proposed method owns wide linear ranges, low limits of detection, high enrichment factors, and good precisions and recoveries for SAs in complex milk samples. The recoveries of SAs on TEPM-DP are much higher than those of commercial C18 and activated carbon. The extraction mechanisms are also elucidated via FT-IR, XPS, and comparative experiments.

SIGNIFICANCE

This work reports the first example of design and synthesizing phenazine-based MON in SPE via a simple and rapid solvothermal method. The results reveal the great prospects of TEPM-DP for enriching polar and ionic SAs in complex samples and uncover the potency of phenazine-based MON in sample pretreatment, which will promote the development of MON.

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

BACKGROUND

Sulfonamides (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.

RESULTS

Herein, 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 NOVELTY

A 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.

Effective biodegradation of chlorophenols, sulfonamides, and their mixtures by bacterial laccase immobilized on chitin

Coexisting multi-pollutants like sulfonamides (SAs) and chlorophenols (CPs) in the ecological environment pose a potential risk to living organisms. The development of a strategy for the effective removal of multiple pollutants has become an urgent need. Herein, we systematically investigated the potential of immobilized bacterial laccase to remove chlorophenols (CPs), sulfonamides (SAs), and their mixtures. Laccase from Bacillus pumilus ZB1 was efficiently immobilized on chitin and its thermal stability, pH stability, and affinity to substrates were improved. Reusability assessment showed the immobilized laccase retained 75.5% of its initial activity after five cycles. The removal efficiency of CPs and SAs by immobilized laccase was significantly improved compared with that of free laccase. In particular, the removal of 2,4-dichlorophenol and 2,4,6-trichlorophenol reached 96.9% and 89.3% respectively within 8 h. The immobilized laccase could remove 63.70% of 2,4-dichlorophenol after four cycles. The degradation pathways of 2,4-dichlorophenol and sulfamethazine were proposed via LC/MS analysis. When the co-pollutants containing 2,4,6-trichlorophenol and sulfamethoxazole, immobilized laccase showed 100% removal of 2,4,6-trichlorophenol and 38.71% removal of sulfamethoxazole simultaneously. Cytotoxicity and phytotoxicity tests indicated that immobilized laccase can alleviate the toxicity of co-pollutants. The results demonstrate that chitin-based laccase immobilization can be an effective strategy for the removal of SAs, CPs, and their co-pollutants.

Construction of multifunctional NH2-UiO-66 metal organic framework: sensing and photocatalytic degradation of ketorolac tromethamine and tetracycline in aqueous medium

Existence of pharmaceutical residues in water has endangered environmental pollution worldwide, which makes it ineludible to develop prospective bifunctional materials which not only possess excellent fluorescence behaviour to monitor pharmaceuticals but also exhibit simultaneous photocatalytic removal efficiency. Strengthened by functionalized metal organic framework (MOF) materials, we present here an amine functionalized zirconium-based MOF NH₂-UiO-66 which has been successfully synthesized using solvothermal approach. The as prepared MOF was subjected to numerous structural, morphological and compositional characterizations. Interestingly, featured by the excellent fluorescent intensity of MOF modulated by LMCT effect, NH₂-UiO-66 was screened to detect pharmaceutical compounds with KTC and TC in aqueous solution. The prepared functionalized MOF showcased excellent sensing platform with magnificent response range (0‒3 µM), lower limit of detection (160 nM; KTC and 140 nM; TC), excellent selectivity and influential anti-interference capability. More importantly, the practical utility of the proposed sensor was further explored for the determination of pharmaceutical drugs in real water samples with suitable recoveries. Simultaneously, the synthesized MOF also exhibited high photocatalytic efficiency towards the removal of KTC and TC under solar light irradiation. The degradation efficiency for KTC and TC was found to be 68.3% and 71.8% within 60 and 280 min of solar light, respectively. Moreover, excellent recyclability was demonstrated by the current synthesized system over five cycles. Overall, this study presents a feasible route for the utilization of functionalized MOFs as potential dual functional materials towards the simultaneous detection and degradation of specific pharmaceuticals from aqueous medium.

Strategies for studying in vivo biochemical formation pathways and multilevel distributions of sulfanilamide metabolites in food (2012-2022)

Sulfonamide metabolites are a major source of food pollution worldwide. However, the formation of internal sulfanilamide metabolites has only been investigated for selected compounds. In this paper, the fragmentation mechanism and characteristic ions of sulfonamide metabolites are reviewed using density functional theory and Q-Orbitrap high-resolution mass spectrometry. The result of the protonation site, rearrangement and bond breaking induced fragmentations at C₆H₆NO₂S⁺m/z 156.01138, C₆H₆NO⁺m/z 108.04439, and C₆H₆N⁺m/z 92.04948. Mass shifts are calculated for derivative metabolites, including hydrogenation, acetylation, oxidation, glucosylation, glucosidation, sulfation, deamination, formylation, desulfonation and O-aminomethylation. Given their homologous series, it is demonstrated that similar metabolic reactions occur for all sulfonamides. The suspicious sulfonamide metabolites are confirmed by d-labelling experiments and reference standards. This is the first review of the latest advances in the field of sulfonamide metabolite prediction (2012-2022), and scheme design for metabolite multirresidue screening, as well as the challenges in the mass spectrometry evolution.

Molecular Imprinted ZnS Quantum Dots-Based Sensor for Selective Sulfanilamide Detection

Combining molecular imprinted polymers and water-soluble manganese-doped zinc sulfide quantum dots (Mn2+: ZnS QDs), a new molecule imprinted polymers-based fluorescence sensor was designed. The molecule imprinted quantum dots (MIP@QDs) were constructed by coating molecular imprinted polymers layer on the surface of ZnS: Mn2+ QDs using the surface molecular imprinting technology. The developed MIP@QDs-based sensor was used for rapid and selective fluorescence sensing of sulfanilamide in water samples. The binding experiments showed that the MIP@QDs has rapid fluorescent responses, which are highly selective of and sensitive to the detection of sulfanilamide. The respond time of the MIP@QDs was 5 min, and the imprinting factor was 14.8. Under optimal conditions, the developed MIP@QDs-based sensor shows a good linearity (R2 = 0.9916) over a sulfanilamide concentration range from 2.90 × 10-8 to 2.90 × 10-6 mol L-1, with a detection limit of 3.23 × 10-9 mol L-1. Furthermore, the proposed MIP@QDs-based sensor was applied to the determination of sulfanilamide in real samples, with recoveries of 96.80%-104.33%, exhibiting good recyclability and stability. Experimental results showed that the prepared MIP@QDs has the potential to serve as a selective and sensitive sensor for the fluorescence sensing of sulfonamides in water samples.

Development of a rapid efficient solid-phase microextraction: An overhead rotating flat surface sorbent based 3-D graphene oxide/ lanthanum nanoparticles @ Ni foam for separation and determination of sulfonamides in animal-based food products

In this study, an overhead rotating flat surface sorbent based solid-phase microextraction was developed as a rapid and efficient method for simultaneous separation and determination of sulfonamides in animal based-food products. 3D graphene oxide/ lanthanum nanoparticles @ Ni foam was introduced as a novel selective sorbent. SEM-EDX and FT-IR techniques were applied for characterization of the sorbent. At optimum conditions, the linear ranges of 0.4-700.0 (µg L^-1), 0.3-900.0 (µg L^-1), and 0.25-500 (µg L^-1) and the enrichment factors of 606.8, 604.3, 608.9 were obtained for SDZ, SMX, and SMZ, respectively. The LOD (S/N = 3) of 0.14, 0.11, 0.08 (µg L^-1) were achieved for SDZ, SMX, and SMZ, respectively. The intra-day and inter-day precision (%) (five days, n = 7) for the concentration of 100 µg L^-1 were less than 4.3 and 3.8, respectively. The recoveries over 90.0 % revealed high capability of the method for utilization in complex matrixes.

Preparation of molecularly imprinted resin/polydopamine nanofibers mat for the highly efficient extraction and determination of sulfonamides in environmental water

With polyacrylonitrile nanofibers mat (PAN NFsM) as a template, molecularly imprinted resin/polydopamine nanofibers mat (MIR/PDA NFsM) was synthesized for the extraction of sulfonamides (SAs) in water. The specific surface area and pore volume were increased obviously due to the functionalization of MIR. The adsorption efficiencies of MIR/PDA NFsM under optimized conditions for SAs were 92.3-99.3%. Possible adsorption mechanisms of imprinting recognition and hydrogen bond interactions were also put forward. Compared with MIR particles, the MIR/PDA NFsM exhibited much superior adsorption performance. Particularly, the outstanding mass transfer efficiency of MIR/PDA NFsM was much higher than the other reported adsorbents for SAs. Finally, a new method based on the solid-phase extraction (SPE) of MIR/PDA NFsM was successfully developed for the detection of five SAs in environmental water with HPLC-MS/MS and applied to the analysis of actual samples. Under the selected conditions, the enrichment factors of MIR/PDA NFsM of SCP, SMT, SMZ, SMR, and SMX were between 23.0 and 25.0. Low detection limits (0.26-0.76 ng L^-1), broad linear range (1.0 ng L^-1 to 10.0 μg L^-1), and satisfactory recoveries (82.8-115.6%) and precisions (RSDs < 7.2%) were obtained. Moreover, the excellent reusability properties and storage stability endowed MIR/PDA NFsM with great value for practical applications.

A nanocomposite adsorbent of metallic copper, polypyrrole, halloysite nanotubes and magnetite nanoparticles for the extraction and enrichment of sulfonamides in milk

A composite adsorbent composed of metallic copper (Cu), polypyrrole (PPy), halloysite nanotubes (HNTs) and magnetite nanoparticles (Fe₃O₄) was developed to extract and enrich sulfonamides by dispersive magnetic solid phase extraction. The composite could adsorb sulfonamides via hydrogen bonding and hydrophobic, π-π and π-electron-metal interactions. The extraction conditions were optimized and the developed composite adsorbent was characterized and provided a large surface area that enhanced extraction efficiency for sulfonamides. Coupled with high performance liquid chromatography, the adsorbent was used to quantitatively determine sulfonamides found in milk samples. The response of the developed method exhibited linearity from 5.0 to 150.0 μg kg^-1 for sulfathiazole, and from 2.5 to 100.0 μg kg^-1 for sulfamerazine, sulfamonomethoxine and sulfadimethoxine. Limits of detection were between 2.5 and 5.0 μg kg^-1. Recoveries of sulfonamides in milk samples ranged from 83.0 to 99.2% with RSDs lower than 6%. The developed composite adsorbent showed good reproducibility and reusability.

A sulfamethoxazole molecularly imprinted two-dimensional photonic crystal hydrogel sensor

In this paper, a molecularly imprinted two-dimensional photonic crystal hydrogel sensor (SMZ-MIPCH) for the sensitive and label-free recognition of sulfamethoxazole (SMZ) was prepared. The SMZ-MIPCH sensor response performance was investigated via measuring the diameter of the Debye ring (D). When the SMZ-MIPCH sensor recognized SMZ, the diameter of the Debye ring gradually decreased and the particle spacing (d) of the photonic crystals gradually increased. As the SMZ concentration increased from 0 to 10-4 mol L-1, the diameter decreased by 15.2 mm and the corresponding particle spacing increased by 131 nm. As the diffraction peak wavelength of the sensor gradually red-shifted, the color changed from blue to green and finally to orange-red. A good linear relationship was found between the variation of the particle spacing (Δd) and the value of the logarithm of the SMZ concentration (lg c) in the range from 10-16 mol L-1 to 10-10 mol L-1. The limit of detection of the SMZ-MIPCH sensor is 10-16 mol L-1. In the presence of analogues of SMZ, such as sulfisoxazole, sulfadiazine, and sulfamethazine, the diameter changed only slightly, indicating that the SMZ-MIPCH sensor had specific recognition abilities for SMZ. The SMZ-MIPCH sensor has the advantages of high sensitivity, specific recognition, and naked eye detection, and it can be used for the detection of SMZ in water samples.

[Research progress of solid phase extraction materials in the application of metal ion pretreatment]

Monitoring of trace heavy metal pollutants released during industrial and agricultural processes is essential because of their widespread distribution in the environment and health hazards. Several techniques, including inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma-optical emission spectrometry (ICP-OES), electrothermal atomic absorption (ETAAS), and flame atomic absorption spectrometry (FAAS), have been proposed for the determination of heavy metals in serum, plasma, whole blood, and food. All these techniques have earned robust recognition in the field of trace heavy metals and have many advantages such as multi-elemental analysis capability, large dynamic linear range, low detection limits, and high productivity. Nevertheless, most of the recommended techniques require digestion of the sample and extraction with an organic solvent for isolation of the metal ion from the sample solution prior to analysis. Despite improvements in the performance of modern analytical instruments, the direct determination of heavy metal ions in real samples is difficult because of their low concentration levels and matrix interference. Thus, extraction and clean-up steps are required for pre-concentration of the analyte, so that detection and elimination of the interfering matrix component are possible. Solid-phase extraction (SPE) is one of the popular metal ion pretreatment methods. The advantages of SPE include easy cartridge/column regeneration, high analytical frequency, and high preconcentration factors for sorbents with high adsorption capacities. On the other hand, when the analytes are extracted from a complex matrix such as serum and meat samples, large amounts of proteins from the samples can be retained on the sorbent surface, obstructing the binding sites on the sorbent and leading to poor precision and accuracy. The key to metal ion detection is the development of new SPE materials with high efficiency and enrichment factors as well as an effective pretreatment technology. Nanomaterials such as restricted-access carbon nanotubes, nanoadsorbents, nanoparticle carriers, and magnetic nanoparticles have shown great promise in advancing biomedical and environmental analysis because of the unique properties originating from their ultrafine dimensions. Nanomaterials can provide large specific surface areas and tunable functional groups to facilitate metal ion absorption. They could also possess superior optical properties and allow for high sensitivity in simple fluorescent or colorimetric detection methods. Owing to their excellent mechanical and chemical stability, polymer materials have been of great interest as adsorbents for the SPE of metal ions from solution. Moreover, a designed polymeric material can show triple functionality such as physical adsorption, chelate formation, and ion exchange for the target metal ions. A dual-functional nanomaterial-DNAzyme platform can simultaneously allow for the sensitive detection and effective removal of heavy metal ions in water. Thus, this platform can serve as a simple, cost-effective tool for rapid and accurate metal quantification in the determination of human metal exposure and inspection of environmental contamination. Furthermore, the new photocaged chelator can uncage and release the combined metal ions into an aqueous solution that is free of the other components of the matrix. In this manner, we can develop diagnostic tests for metal ions that are often difficult to detect using other methods. In this paper, the characteristics of new SPE materials, including nanomaterials, polymer materials, and functional materials as well as advances in their applications to the preparation of complex samples are summarized, and the direction for future development is proposed.

Determination of sulfonamide residues in animal foodstuffs by magnetic dispersive solid-phase extraction using magnetic carbon nanocomposites coupled with ion pair-dispersive liquid–liquid micro-extraction combined with HPLC-DAD

In this study, magnetic-dispersive solid-phase extraction coupled with ion pair-dispersive liquid–liquid micro-extraction (MSPE-i-DLLME) was used to the pre-concentration and extraction of five sulfonamides residues (sulfadiazine, sulfathiazole, sulfacetamide, sulfamethazine and sulfamethoxazole) in animal foodstuffs. The sulfonamides are extracted using magnetic carbon nanocomposite and then eluted with acetonitrile. In the DLLME step, the target analytes are collected in 1-octanol containing 10% Aliquat-336 (as extraction solvent). Finally, the compounds are quantified by HPLC with DAD detection. The extraction parameters optimized using the one at the time and central composite design methods. Under the optimized conditions: sample solution volume was 100 mL; initial pH: 12, amounts of MCNs: 30 mg; desorption solvent (ACN) volume, 1 mL; desorption condition, 10 min sonication at two step; extraction solvent (1-octanol + 10% aliquat) volume, 115 µL; pH of DLLME step, 3; salt effect, 24.6%, (w/v) NaCl; centrifuge, 5 min, 4000 rpm. In these extraction conditions, the proposed procedure represented good pre-concentration factors between 130 and 490; detection limits in the range from 0.01 to 5 μg kg−1 (at S/N = 3), and linear response in the 0.1–400 μg kg−1 concentration range. The method is successfully applied to the determination of sulfonamides residues in animal foodstuffs.

Greenness of magnetic nanomaterials in miniaturized extraction techniques: A review

Green analytical chemistry principles should be followed, as much as possible, and particularly during the development of analytical sample preparation methods. In the past few years, outstanding materials such as ionic liquids, metal-organic frameworks, carbonaceous materials, molecularly imprinted materials, and many others, have been introduced in a wide variety of miniaturized techniques in order to reduce the amount of solvents and sorbents required during the analytical sample preparation step while pursuing more efficient extraction methods. Among them, magnetic nanomaterials (MNMs) have gained special attention due to their versatile properties. Mainly, their ability to be separated from the sample matrix using an external magnetic field (thus enormously simplifying the entire process) and their easy combination with other materials, which implies the inclusion of a countless number of different functionalities, highly specific in some cases. Therefore, MNMs can be used as sorbents or as magnetic support for other materials which do not have magnetic properties, the latter permiting their combination with novel materials. The greenness of these magnetic sorbents in miniaturized extractions techniques is generally demonstrated in terms of their ease of separation and amount of sorbent required, while the nature of the material itself is left unnoticed. However, the synthesis of MNMs is not always as green as their applications, and the resulting MNMs are not always as safe as desired. Is the analytical sample preparation field ready for using green magnetic nanomaterials? This review offers an overview, from a green analytical chemistry perspective, of the current state of the use of MNMs as sorbents in microextraction strategies, their preparation, and the analytical performance offered, together with a critical discussion on where efforts should go.

Selective extraction and enhanced-sensitivity detection of fluoroquinolones in swine body fluids by liquid chromatography-high resolution mass spectrometry: Application in long-term monitoring in livestock

To ensure food safety in livestock industries, developing a non-lethal and cost-effective detection method for the long-term monitoring of veterinary antibiotics in animals will be beneficial to avoid unnecessary losses. In this study, a highly-selective extraction using dispersive micro solid-phase extraction method coupled with an enhanced-sensitivity detection by pre-column dilution injection and liquid chromatography-high resolution mass spectrometry was used to determine the restricted fluoroquinolones (FQs) in swine body fluids. The proposed method showed good linear coefficients higher than 0.999, and high sensitivity with the LODs and LOQs in the range of 0.02-0.03 μg/L and 0.06-0.1 μg/L in swine body fluids, respectively. For further evaluation, the adequate recoveries (85.3-112.8%), satisfactory repeatability (intra-day and inter-day precisions of 2.1%-8.2% and 3.8%-13.7%, respectively), and acceptable matrix effect (0.92-1.12) of the FQs were achieved. It has been successfully applied for analysis of the FQs in body fluids without sacrificing animals in the future.