Determination of multiple antibiotics in leafy vegetables using QuEChERS-UHPLC-MS/MS

Distribution pattern analysis of multiple antibiotics in the soil-rice system using a QuEChERS extraction method

Antibiotics are commonly released into paddy fields as mixtures via human activities. However, the simultaneous extraction and detection of these chemicals from multiple media are technically challenging due to their different physicochemical properties, resulting in unclear patterns of their transport in the soil-rice system. In this study, a "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) method was developed for the simultaneous analysis of 4 tetracyclines (TCs) and 4 fluoroquinolones (FQs) in the soil and rice tissues from a local poultry farm, and thereby the distribution patterns of the target antibiotics in the soil-rice system and their risk levels to the soil were analyzed. After parameter optimization, the calibration range used for the target antibiotics was 0.1-50 μg/L and each calibration curve was linear with a coefficient of determination (R2 > 0.995); The QuEChERS method achieved satisfactory recovery rates (70.3-124.6%) along with sensitive detection limits (0.005-0.21 ng/g) for TCs and FQs in the soil, root, stem, leaf, and grain. Among the 8 antibiotics, enrofloxacin (ENX), ciprofloxacin (CIP), oxytetracycline (OTC), and doxycycline (DOX) were detected around a poultry farm. The four antibiotics in the collected paddy soils around the poultry farm ranged from 7.1 ng/g to 395.5 ng/g. Notably, ENX and DOX had higher ecological risks (risk quotient values >1) than CIP and OTC in soil. ENX, CIP, and DOX were highly enriched in rice roots with concentrations up to 471.9, 857.3, and 547.4 ng/g, respectively, which were also detected in rice aboveground tissues. The findings may provide both technical and practical guidance for the understanding of antibiotic environmental behavior and risks.

Multiclass Analysis for the Determination of Pharmaceuticals and Their Main Metabolites in Leafy and Root Vegetables

The irrigation of soils with reclaimed contaminated wastewater or its amendment with sewage sludge contributes to the uptake of pharmaceuticals by vegetables growing in the soil. A multiresidue method has been devised to determine five pharmaceuticals and nine of their main metabolites in leafy and root vegetables. The method employs ultrasound-assisted extraction, clean-up via dispersive solid-phase extraction, and analysis through liquid chromatography-tandem mass spectrometry. Box-Behnken design was used to refine variables such as extraction solvent volume, time of extraction, number of extraction cycles, and the type and amount of d-SPE sorbent. The method achieved linearity (R2) greater than 0.994, precision (relative standard deviation) under 16% for most compounds, and detection limits ranging from 0.007 to 2.25 ng g-1 dry weight. This method was applied to a leafy vegetable (lettuce) and to a root vegetable (carrot) sourced from a local market. Parent compounds were detected at higher concentrations than their metabolites, with the exception of carbamazepine-10,11-epoxide.

Multitarget and suspect-screening of antimicrobials in vegetables samples: Uptake experiments and identification of transformation products

This work provided an accurate analytical method to perform a multitarget analysis of a variety of antimicrobials (AMs) including sulfonamides, tetracyclines, macrolides, fluoroquinolones and quinolones, one imidazole and one nitroimidazole, one triazole, one diaminopyridine and one derivative of Penicillium stoloniferum in vegetables. The analysis is performed using liquid-chromatography coupled to a low-resolution triple quadrupole mass spectrometer (UHPLC-MS/MS) to detect the target analytesor coupled to a high-resolution q-Orbitrap (HRMS) to monitor the formed transformation products (TPs). Both instruments were compared in terms of limits of quantification and matrix effect at the detection. The method was applied to determine the presence of AMs in organic and non-organic vegetables, where sulfadiazine and mycophenolic acid were detected. On the other hand, the transference of four AMs (trimethoprim, sulfamethazine, enrofloxacin, and chlortetracycline) from soils to lettuces was evaluated through controlled uptake experiments. The choice of AMs was based on the classification into different families, and on the fact that those AM families are the most frequently detected in the environment. In this case, each of the AMs with which the soils were contaminated were found in the exposed lettuces. Moreover, in both studies, specific TPs of the AMs were identified, posing the necessity of assessing their effects in relation to food and human safety.

Optimization and validation of multiresidual extraction methods for pharmaceuticals in Soil, Lettuce, and Earthworms

The presence of human and veterinary pharmaceuticals (PhACs) in the environment poses potential risks. To comprehensively assess these risks, robust multiresidual analytical methods are essential for determining a broad spectrum of PhAC classes in various environmental compartments (soil, plants, and soil organisms). This study optimized extraction methods for analyzing over 40 PhACs from various matrices, including soil, lettuce, and earthworms. A four-step ultrasonic extraction method with varying extraction conditions and subsequent solid phase extraction was developed for soil samples. QuEChERS methods were optimized for extracting PhACs from lettuce and earthworm samples, addressing a literature gap in these less-studied matrices. The quantification of PhACs in soil, lettuce, and earthworm extracts was performed using a single LC-MS/MS method. Following thorough method validation, earthworms and lettuce were exposed to a mixture of 27 pharmaceuticals in a soil environment. The method validation results demonstrated the robustness of these methods for a broad spectrum of PhACs. Specifically, 29 out of 42 PhACs were extracted with an average efficiency > 50% and RSD < 30% from the soil; 40 out of 42 PhACs exhibited average efficiency > 50% and %RSD < 30% from the earthworms, while 39 out of 42 PhACs showed average efficiency > 50% and RSD < 30% from the lettuce. Exposure experiments confirmed the viability of these methods for quantifying a diverse range of PhACs in different environmental compartments. This study presents three thoroughly validated methods for determining more than 40 PhACs in diverse matrices, enabling a comprehensive assessment of PhAC dissemination in the environment.

A Suitable HPLC-MS/MS Methodology for the Detection of Oxytetracycline, Enrofloxacin, and Sulfachloropyridazine Residues in Lettuce Plants

Oxytetracycline (OTC), enrofloxacin (EFX), and sulfachloropyridazine (SCP) are critically important antimicrobials (AMs) in both human and veterinary medicine, where they are widely used in farm animals. Lettuce has become a matrix of choice for studying the presence of residues of these AMs in plants, as the concentrations of residues detected in lettuce can range from ng to mg. While several analytical methodologies have been developed for the purpose of detecting AMs in lettuce, these currently do not detect both the parent compound and its active metabolites or epimers, such as in the case of ciprofloxacin (CFX) and 4-epi-oxitetracycline (4-epi-OTC), which also pose a risk to public health and the environment due to their AM activity. In light of this situation, this work proposes an analytical method that was developed specifically to allow for the detection of OTC, 4-epi-OTC, EFX, CFX, and SCP in a lettuce matrix. This method uses acetonitrile, methanol, 0.5% formic acid, and McIlvaine-EDTA buffer as extraction solvents, and dispersive solid-phase extraction (dSPE) for the clean-up. The analytes were detected using a liquid chromatography technique coupled to mass spectrometry (HPLC-MS/MS). Parameters such as the specificity, linearity, recovery, precision, limit of detection, and limit (LOD) of quantification (LOQ) were calculated according to the recommendations established in the European Union decision 2021/808/EC and VICH GL2: Validation of analytical procedures. The LOQ for the analytes OTC, 4-epi-OTC, CFX, and SCP was 1 μg·kg-1, whereas for EFX, it was 5 μg·kg-1 dry weight. All calibration curves showed a coefficient of determination (R2) of >0.99. The recovery levels ranged from 93.0 to 110.5% and the precision met the acceptance criteria, with a coefficient of variation of ≤14.02%. Therefore, this methodology allows for the precise and reliable detection and quantification of these analytes. The analysis of commercial samples confirmed the suitability of this method.

Validation of modified QuECHERS extraction method for quantitative enrichment of seven multiclass antibiotic residues from vegetables followed by RP-LC-UV analysis

A modified rapid, simple quick, cheap, effective, robust and safe (QuEChERS) extraction method was developed for the simultaneous extraction and purification of seven antibiotic residues in lettuce, carrot and tomato using liquid chromatography UV detector. The method was validated for linearity, sensitivity, accuracy, repeatability, and reproducibility at six concentration levels for all matrices, according to the guidelines of UNODC. A matrix-matched calibration method was used for the quantitative analysis. Linear range of 0.01-250 μg kg^-1 for target compounds with correlation coefficient (R²) 0.9978-0.9995 was obtained. The limits of detections (LODs) and quantifications (LOQs) were 0.02-2.48 μg kg^-1 were 0.06-7.52 μg kg^-1, respectively. The average recoveries of the seven antibiotics ranged from 74.5 to 105.9%, with relative standard deviation RSD (%) < 11, for all matrices and matrix effects were less than 20% for most of compounds. This comprehensive simple QuEChERS extraction method can be used for the investigation of multi-residue drugs belonging to different chemical families in vegetables.

Comparison of conventional and dispersive solid phase extraction clean-up approaches for the simultaneous analysis of tetracyclines and sulfonamides in a variety of fresh vegetables

The extensive use of antibiotics in agriculture has led to the occurrence of residual drugs in different vegetables frequently consumed by humans. This could pose a potential threat to human health, not only because of the possible effects after ingestion but also because the transmission of antibiotic-resistant genes could occur. In this work, two accurate sample preparation procedures were developed and validated for the simultaneous analysis of sulfonamides (SAs) and tetracyclines (TCs) in four of the most widely consumed vegetables (lettuce, onion, tomato, and carrot) in Europe. The evaluated protocols were based on QuECHERS for extraction and subsequent clean-up by SPE (solid phase extraction) or dispersive SPE. Parameters affecting both extraction and clean-up were carefully evaluated and selected for accuracy of results and minimal matrix effect. Overall, apparent recoveries were above 70% for most of the target analytes with both analytical procedures, and adequate precision (RSD<30%) was obtained for all the matrices. The procedural limits of quantification (LOQPRO) values for SPE clean-up remained below 4.4 μg kg-1 for TCs in all vegetables except for chlortetracycline (CTC) in lettuce (11.3 μg kg-1) and 3.0 μg kg-1 for SAs, with the exception of sulfadiazine (SDZ) in onion (3.9 μg kg-1) and sulfathiazole (STZ) in carrot (5.0 μg kg-1). Lower LOQPRO values (0.1-3.7 μg kg-1) were obtained, in general, when dSPE clean-up was employed. Both methods were applied to twenty-five market vegetable samples from ecological and conventional agriculture and only sulfamethazine (SMZ) and sulfapyridine (SPD) were detected in lettuce at 1.2 μg kg-1 and 0.5 μg kg-1, respectively.

Occurrence and risk assessment of antibiotics in feces of elderly individuals in Shenzhen

The occurrence of antibiotics in the feces of elderly individuals in Shenzhen, China, was investigated by monitoring 78 compounds to understand the adverse effects and its association with antibiotic residues in animal products collected from local markets. In total, 18 compounds belonging to 5 classes of antibiotics were identified in 74 of 140 fecal samples. Furthermore, 17.9% of the fecal samples contained at least two antibiotics, and 14.3% of the samples showed antibiotic concentrations higher than 100 μg/kg. Cephalothin exhibited the highest detection frequency (22.1%), followed by azithromycin (15.7%) and tilmicosin (12.9%). Oxytetracycline, norfloxacin, and azithromycin showed extremely high concentrations (> 1000 μg/kg). Eight antibiotics were detected in the animal products, with detection frequencies ranging from 4.8 to 40.0%. Five antibiotics exhibited similar detection frequencies and strong correlations between the human fecal and animal product samples. Health risk assessment based on hazard quotients showed that ciprofloxacin in animal products and human feces posed a medium and high risk, respectively. The hazard quotients of oxytetracycline, norfloxacin, and azithromycin in the feces were greater than 1, indicating a high health risk. These findings suggest that the elderly individuals were frequently exposed to antibiotics via the food chain and faced health risks posed by these antibiotics.

Green and Efficient Determination of Fluoroquinolone Residues in Edible Green Fruits and Leafy Vegetables by Ultrasound-Assisted Extraction Followed by HPLC-MS/MS

In this work, a simple, quick and efficient analytical method for determination of human and veterinary fluoroquinolone antimicrobial residues in lettuce, cucumber and spinach is developed. The procedure entails a 6 min ultrasound-assisted extraction (UAE, 3 × 2 min) in an alkaline (2% v/v NH₃) aqueous solution containing Mg²⁺ ions (3 × 6 mL), with no need for organic solvents. The extract is submitted to cleanup on the HLB™ cartridge and the fluoroquinolones are separated and quantified by HPLC-MS/MS in a 10 min chromatographic run, using a small amount of acetonitrile in the mobile phase. The method, entirely developed in real matrices, is validated according to the updated analytical guidelines and provided suitable recoveries in the range of 67–116% and precision (RSD ≤ 20%, n = 3) at different concentrations (15, 70 and 150 ng g⁻¹), with method quantification limits of 2–10 ng g⁻¹. Fluoroquinolones were detected and quantified at concentrations from few to hundreds of nanograms per gram in vegetables from supermarkets, demonstrating the applicability of the method for monitoring residues of these pharmaceuticals.

Self-synthesized TiO2 nanoparticles-pH-mediated dispersive solid phase extraction coupled with high performance liquid chromatography for the determination of quinolones in biological matrices

A simple and efficient pH-mediated dispersive solid phase extraction (dSPE) based on terbium doped titanium dioxide nanoparticles (TiO₂-Tb NPs) combined with high performance liquid chromatography (HPLC) has been firstly developed for the determination of quinolones (QNs) in various biological samples. The adsorption kinetics and isotherms were investigated to indicate that the kinetic and equilibrium adsorption were well-described by pseudo-second order kinetic and Henry, Langmuir isotherm model, respectively. The parameters influencing the extraction performance were systematically investigated. The QNs are transferred into TiO₂-Tb NPs in the first step at pH = 6.0 and eluted into acidic aqueous phase at pH = 2.5 in the second step. Under the optimum extraction and determination conditions, a linearity range with the coefficient of determination (R²) from 0.9977 to 0.9991 were obtained in a range of 10-10,000 ng mL^-1. The limits of detection (LODs) based on a signal-to-noise ratio of 3 were 3.3 ng mL^-1. The recoveries of the three QNs in human urine, rabbit plasma and serum samples ranged from 69.3% to 117.6%, with standard deviations ranging from 2.4% to 9.9%. Therefore, this pH-mediated dSPE-HPLC method exhibited the advantages of remarkable sensitivity, ease of operation, rapidity, low cost and environmental friendliness.

The Safety of Consuming Water Dropwort Used to Purify Livestock Wastewater Considering Accumulated Antibiotics and Antibiotic Resistance Genes

Research is lacking on the health risks of antibiotics and antibiotic resistance genes (ARGs) in water dropwort grown in livestock wastewater. Our results showed that antibiotics from livestock wastewater were absorbed and bioaccumulated by water dropwort. The concentration of antibiotics was higher in the roots than in the stems and leaves. The health-risk coefficients of antibiotics in water dropwort were below the threshold (<0.1), indicating that in this case study, the consumption of water dropwort used to purify livestock wastewater was safe for humans considering accumulated antibiotics. ARGs were closely correlated between livestock wastewater and water dropwort, with the results showing that all 13 ARGs detected in the livestock wastewater were also found in the water dropwort. Tetracycline resistance genes were more abundant than the other ARGs in both the livestock wastewater and water dropwort. The estimated daily intake of ARGs in water dropwort for humans ranged from 2.06 × 106 to 7.75 × 1012 copies g−1, suggesting the potential risk of intaking ARGs in water dropwort cannot be ignored. Although the safety of consuming water dropwort used to purify livestock wastewater, considering accumulated antibiotics and ARGs, was assessed in this study, more studies should be conducted to ensure we fully understand the health risks.

The mechanism of uptake and translocation of antibiotics by pak choi (Brassica rapa subsp. chinensis)

Antibiotic uptake by vegetables from the environment is one pathway in which humans are exposed to antibiotics through the food chain and can pose potential risks to human health. Therefore, understanding the mechanism of how antibiotics enter vegetables will contribute to developing effective measures to reduce antibiotic contamination in crops. In this study, a series of hydroponic experiments were conducted to investigate the uptake and translocation of six antibiotics in pak choi. The results showed the accumulation capacity of fluoroquinolones was significantly higher than that of tetracycline and sulfamethoxypyridazine. The antibiotic uptake kinetics in roots were well described by the Michaelis-Menten equation. The results for the metabolic inhibitor, aquaporin inhibitor, and transpiration inhibitor showed that the uptake processes for ofloxacin, norfloxacin, and enrofloxacin were energy-dependent, those for sulfamethoxypyridazine and ciprofloxacin were aquaporin-dependent, and that for tetracycline was energy- and aquaporin-dependent. Antibiotic translocation was associated with water transport through xylem vessels, which could be controlled by aquaporin activities and transpiration. Roots were the main accumulator of antibiotics, and the degradation percentages of tetracycline, norfloxacin, enrofloxacin, and ofloxacin by Pak choi were 0-14.48% within 72 h. Overall, our findings provide a better understanding of the transfer of antibiotics from the environment to vegetables, which will be of great significance for developing optimal management practices to mitigate antibiotic contamination in vegetables and ensuring food safety.

A contrasting alteration of sulfamethoxazole bioaccessibility in two different soils amended with polyethylene microplastic: In-situ measurement using diffusive gradients in thin films

Microplastics and veterinary antibiotics are both emerging environmental contaminants that could be co-occurrence in agricultural soils. However, it's still unclear how the microplastics affect the bioaccessibility of antibiotics in a real soil environment. An in-situ measurement using diffusive gradients in thin-films devices suitable for polar organic compounds (o-DGT) coupled with soil moisture sampling were used to reveal such effects. Sulfamethoxazole (SMX) that was selected as a representative antibiotic and polyethylene (PE) microplastic with an average diameter of 35 μm were amended to the paddy soil and saline soil for the study. The result indicated that SMX degradation in the paddy soil was higher than that in the saline soil, meanwhile, PE microplastic addition promoted SMX degradation in both soils. In the paddy soil, PE microplastic addition enhanced release of SMX from soil solid to soil solution but no effects on the bioaccessibile SMX. However, in the saline soil, the PE microplastic addition reduced both SMX in soil solution and bioaccessibile SMX significantly (p < 0.05). The potential resupply ability of the labile SMX from soil solid to soil solution which was expressed as R value enhanced significantly in saline soil, while such a change was negligible in the paddy soil. This implied that long-term release risk of SMX in the PE microplastic contaminated saline soil could not be neglected. Therefore, co-occurrence of PE microplastic and SMX in the soils might increase uptake of SMX by biotas and such effects depended on soil properties.

Room temperature fabrication of magnetic covalent organic frameworks for analyzing sulfonamide residues in animal-derived foods

A magnetic solid phase extraction method based on magnetic covalent organic frameworks (TpBD@Fe₃ O₄ ) combined with high performance liquid chromatography has been developed to detect the sulfonamides including sulfadiazine, sulfamerazine, sulfamethazine and sulfamethoxazole in milk and meat. TpBD@Fe₃ O₄ were synthesized at room temperature under mild reaction conditions with a simple and rapid operation. The TpBD@Fe₃ O₄ exhibited higher extraction efficiency because of the π-π and electrostatic interactions between the benzene ring structure of the TpBD and the SA molecules. The extraction conditions including the dosage of adsorbents, the type and dosage of eluent, the elution time and the pH of the sample solution were fully optimized. The detection results showed good linearity over a wide range (50-5×10⁴ ng/mL) and low detection limits (3.39-5.77 ng/mL) for the SA targets. The practicability of this MSPE-HPLC method was further evaluated by analyzing milk and meat samples, with recoveries of the targets of 71.6%-110.8% in milk and 71.9%-109.7% in pork. The successful detection of SAs residues has demonstrated the TpBD@Fe₃ O₄ excellent practical potential for analyzing pharmaceutical residues in animal-derived foods. This article is protected by copyright. All rights reserved.

Determination of 18 Intact Glucosinolates in Brassicaceae Vegetables by UHPLC-MS/MS: Comparing Tissue Disruption Methods for Sample Preparation

Glucosinolates (GSLs) are important precursor compounds with anticancer activities in Brassicaceae vegetables and are readily hydrolyzed by myrosinase. Given the diversity of these species, establishing an accurate and universal method to quantify intact GSLs in different plant tissues is necessary. Here, we compared and optimized three tissue disruption methods for sample preparation. After microwave treatment for 90 s, 13 GSLs in homogenized Chinese cabbage samples were recovered at 73–124%. However, a limitation of this method was that different tissues could not be processed under the same microwave conditions. Regarding universality, GSLs in Brassicaceae vegetables could be extracted from freeze-dried sample powder with 70% methanol (v/v) or frozen-fresh sample powder with 80% methanol (v/v). Moreover, heating extraction is necessary for GSLs extracted from frozen-fresh sample powder. Average recoveries of the two optimized methods were 74–119% with relative standard deviations ≤ 15%, with the limits of quantification 5.72–17.40 nmol/g dry weight and 0.80–1.43 nmol/g fresh weight, respectively. Notably, the method for analyzing intact GSLs was more efficient than that for desulfo-GSLs regarding operational complexity, detection speed and quantification accuracy. The developed method was applied to identify the characteristic GSLs in 15 Brassicaceae vegetables, providing a foundation for further research on GSLs.

Antibiotics in urine of the general population: Exposure, health risk assessment, and food factors

Diet is known to be one of the main sources from which human intake many environmental contaminants, for example, antibiotics. To determine the effect of dietary factors on antibiotic intake, we identified the levels of antibiotics present in the urine of the general population from two regions of Shanghai. Moreover, we assessed the amount of exposure to these substances and the health risks they posed. There were a total of 18 antibiotics, which were sorted into five categories. Based on the above, we used the Food Frequency Questionnaire (FFQ) and demographic data to evaluate the effects of food consumption and demographic factors on levels of the antibiotics in urine. The results found that food sourced from animals had a direct relation to the level of veterinary antibiotics or preferred veterinary antibiotics (VAs/PVAs) detected in urine. Those who regularly consumed, for example, meat, milk and eggs, had considerably more VAs/PVAs in their urine compared to those who didn't. These results demonstrated that animal-derived foods are the main causes of unintentional exposure to antibiotics in human. Our study, therefore, evidenced that more attention must be paid to the residues of unneeded VAs/PVAs derived from animal-sourced food.

Determination of multiple antibiotics in agricultural soil using a quick, easy, cheap, effective, rugged, and safe method coupled with ultra-high performance liquid chromatography-tandem mass spectrometry

In this study, we combined ultra-high performance liquid chromatography with tandem mass spectrometry to establish a quick, easy, cheap, effective, rugged, and safe method of detecting 21 target antibiotics in agricultural soil samples. Antibiotics were extracted with mixed solvents consisting of ethylenediaminetetraacetic acid disodium salt dihydrate and phosphoric acid citric acid buffer and acetonitrile which were purified with octadecylsilyl as an adsorbent and anhydrous sodium sulfate as a desiccant. This method was able to effectively extract all of the target antibiotics from agricultural soils, with recovery efficiencies ranging from 55 to 108% and limits of detection between 0.09-0.68 μg/kg. We also validated this new method for selectivity, sensitivity, and reliability of detecting multiple antibiotics in 12 samples. Considering the potential environmental and public health effects of antibiotics in agricultural soils, our new method can help analyze the degree of antibiotic contamination and provide valuable information for soil quality and risk assessment.

Synthesis of molecularly imprinted polymers for extraction of fluoroquinolones in environmental, food and biological samples

In recent years, fluoroquinolones have been found present in important water resources and food sources which compromises the food quality and availability, thereby, causing risks to the consumer. Despite the recent advancement in the development of analytical instrumentation for routine monitoring of fluoroquinolones in water, food, and biological samples, sample pre-treatment is still a major bottleneck of the analytical methods. Therefore, fast, selective, sensitive, and cost-effective sample preparation methods prior to instrumental analysis for fluoroquinolones residues in environmental, food and biological samples are increasingly important. Solid-phase extraction using different adsorbents is one of the most widely used pre-concentration/clean-up techniques for analysis of fluoroquinolones. Molecularly imprinted polymers (MIPs) serve as excellent effective adsorbent materials for selective extraction, separation, clean-up and preconcentration of various pollutants in different complex matrices. Therefore, synthesis of MIPs remains crucial for their applications in sample preparation as this offers much-needed selectivity in the extraction of compounds in complex samples. In this study, the progress made in the synthesis of MIPs for fluoroquinolones and their applications in water, food and biological samples were reviewed. The present review discusses the selection of all the elements of molecular imprinting for fluoroquinolones, polymerization processes and molecular recognition mechanisms. In conclusion, the related challenges and gaps are given to offer ideas for future research focussing on MIPs for fluoroquinolones.

The pesticide residue analysis in commodities with high content of chlorophyll based on the quick, easy, cheap, effective, rugged, and safe method: A review

In multiresidue analysis, the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) is one of the most popular techniques routinely used by researchers during pesticide analysis of food and vegetable samples. Originally, the QuEChERS method was developed for analysis of pesticide residues from fruits and vegetables, but rapidly gained popularity in the extraction of analytes from different matrices. This analytical approach shows several advantages over traditional extraction techniques: it requires lower sample and solvent amounts while shortening the time of sample preparation. However, it presents some limitations for complex matrices such as those containing high amounts of chlorophyll. To overcome the problem of strong matrix effect and influence of interferences, different approaches are applied. Most are concerning modifications of the cleanup step, that is, sorbent type and its amount. Optimization of other parameters, such as sample size, hydration level, extraction solvent, and buffering, also has an impact on overall performance. Combining proper sample preparation with modern highly sensitive and selective detection techniques enables receiving desired limits of quantification. This article presents an overview of strategies employed by researchers for analysis of green, high chlorophyll content commodities and results obtained in their studies.

Review on the fate of antimicrobials, antimicrobial resistance genes, and other micropollutants in manure during enhanced anaerobic digestion and composting

While manure has been used as nutrient-rich fertilizer for centuries, anaerobic digestion (AD) of manure has only been recognized recently as a promising renewable energy source for producing methane-rich biogas. Various forms of AD have been evaluated for the removal of manure contaminants, such as antimicrobials, antimicrobial resistance genes (ARGs), hormones, and pesticides that pose risks to human health and the environment. Increasing demand for cleaner energy prompts examination of the fate of manure contaminants in conventional and advanced AD techniques. This review reveals that removal of contaminants differs based on type (e.g. antimicrobials vs hormones) or class (e.g. tetracyclines vs sulfonamides) of chemicals being treated. Increasingly, pre-treatment techniques are incorporated into AD systems to enhance biogas production and degrade manure contaminants. For instance, activated carbon with microwave pretreatment removed 87-95% of ARGs. Advanced anaerobic digestion and solid-state anaerobic digestion reduced various ARGs associated with sulfonamides, macrolides, and tetracyclines. Further, total hormone reduction improved using high-temperature pretreatment prior to mesophilic AD. Finally, several studies revealed partial removal of antimicrobials and ARGs during managed composting. Although AD can independently decrease manure contaminants prior to use as fertilizer, augmenting AD with composting and other physical treatment processes can further enhance their removal.

Trace analysis of 28 antibiotics in plant tissues (root, stem, leaf and seed) by optimized QuEChERS pretreatment with UHPLC-MS/MS detection

Phytoremediation has proven to be an effective in-situ treatment technique for antibiotic contamination. Due to the immature methods of extracting multi-antibiotics in different plant tissues, the antibiotic absorption and transportation mechanism in the phytoremediation process has yet to be resolved. Therefore, an improved Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) pretreatment with ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) detection method for 28 antibiotics in different plant tissues (root, stem, leaf and seed) was developed in this study. The optimized method showed satisfactory performance with recoveries for most antibiotics ranging from 70% to 130% (except sulfadoxine with 138 ± 8.84% in root, sulfameter with 68.9 ± 1.87% and sulfadoxine with 141 ± 10.0% in seed). The limits of detection (LODs) of the target compounds in root, stem, leaf and seed were 0.04 ± 0.02 ~ 2.50 ± 1.14 ng/g, 0.05 ± 0.02 ~ 1.78 ± 0.42 ng/g, 0.06 ± 0.01 ~ 2.50 ± 0.14 ng/g and 0.13 ± 0.10 ~ 3.64 ± 0.74 ng/g, respectively. This developed method was successfully applied to the determination of antibiotics in different tissues of hydroponic wetland plants exposed to antibiotics-spiked water for one-month. Sixteen of 28 spiked antibiotics were detected in plant tissue samples. Overall, of these 16 antibiotics, all were detected in root samples (from < LOQ to 1478 ± 353 ng/g), eleven in stem samples (from < LOQ to 425 ± 47.0 ng/g), and nine in leaf samples (from < LOQ to 429 ± 84.5 ng/g). This developed analytical method provided a robust tool for the simultaneous screening and determination of antibiotics in different plant tissues.

Comparison of high resolution mrm and sequential window acquisition of all theoretical fragment-ion acquisition modes for the quantitation of 48 wastewater-borne pollutants in lettuce

Screening of a large number of chemicals of emerging concern is highly desirable for the control of crops irrigated with reclaimed water since it is considered an alternative water source of great value. This study describes a high resolution mass spectrometry approach for developing methods for quantification in lettuce leaves of 48 different wastewater-borne pollutants (including analgesics and anti-inflammatories, anti-hypertensives, antifungal agents, lipid regulators, psychiatric drugs and stimulants, β-blockers, antibiotics, antimycotics, and sweeteners) frequently found in water resources. In this respect, a simple and fast QuEChERS-based method for the determination of contaminants in lettuce has been developed. During extraction, the use of formic acid was adopted to further improve the results of some problematic compounds (e.g., fenofibrate, furosemide, metronidazole, oxcarbazepine, sulfanilamide). High resolution multiple reaction monitoring (MRMHR) and SWATH acquisition were compared in term of accuracy, repeatability, sensitivity, linearity and matrix effect. Both methods provided similar recoveries between 80 and 120% in lettuce leaves, although sulfanilamide, ciprofloxacin, and sulfamethazine presenting values of 26.8, 27.8, and 28.4% in MRMHR and 25, 33.9, and 35% in SWATH, respectively. The effectiveness of a two-step cleanup on analyte recovery was also assessed and matrix effects were also taken into consideration during the method validation. The developed method allows the simultaneous quantitative analysis of 48 compounds (drug residues and metabolites) in lettuce leaves irrigated with treated wastewater for human consumption. Application of the present method to lettuce crops growth in controlled conditions showed the presence of 14 out 48 studied compounds with similar concentrations in both acquisition modes ranging from 3.3 and 1.3 ng g - 1 for climbazole (for MRMHR and SWATH, respectively) to 33.2 and 17.7 ng g - 1 for sulfamethazine. Drug residues such as carbamazepine (6.0 and 8.5 ng g - 1), and its metabolite carbamazepine epoxide (18.1 and 16.5 ng g - 1), frequently found in wastewater effluents, were also detected.

Au nanoparticle preconcentration coupled with CE-electrochemiluminescence detection for sensitive analysis of fluoroquinolones in European eel (Anguilla anguilla)

In this work, a novel method based on gold nanoparticle preconcentration coupled with CE for electrochemiluminescence detection of ciprofloxacin, enrofloxacin, ofloxacin, and norfloxacin in European eels was developed. The addition of gold nanoparticles induced the rapid enrichment of fluoroquinolones, which was simpler than the conventional enrichment approaches such as solid phase extraction and solid-phase microextraction. More than 100 times enrichment was observed after gold nanoparticle aggregation-based preconcentration. The CE-electrochemiluminescence parameters that affected the separation and detection were optimized. Under the optimized conditions, the linear ranges for the four fluoroquinolones were 0.090-8.0 μmol L-1 with the detection limits between 0.020 and 0.050 μmol L-1. The proposed approach showed the advantages of high sensitivity, high selectivity, a wide linear range, and a low detection limit. It was used to analyze fluoroquinolones in European eel, and the results showed that the developed method can satisfy the detection requirements for fluoroquinolone determination in aquatic products set by China and the European Union.

Trends in sensitive detection and rapid removal of sulfonamides: A review

Sulfonamides in environmental water, food, and feed are a major concern for both aquatic ecosystems and public health, because they may lead to the health risk of drug resistance. Thus, numerous sensitive detection and rapid removal methodologies have been established. This review summarizes the sample preparation techniques and instrumental methods used for sensitive detection of sulfonamides. Additionally, adsorption and photocatalysis for the rapid removal of sulfonamides are also discussed. This review provides a comprehensive perspective on future sulfonamide analyses that have good performance, and on the basic methods for the rapid removal of sulfonamides.

Occurrence and distribution of clinical and veterinary antibiotics in the faeces of a Chinese population

Antibiotics ingested in the human gut may create selective pressure to change the composition of the gut microbiota, which could adversely effect the immune system of the host. However, the occurrence and distribution of antibiotics in the human gut remains unclear. A total population of 180 individuals, across three Chinses regions with different economic development levels, including children, adults, and elders, were sampled in 2017. A total of 19 representative antibiotics, including both clinical and veterinary antibiotics, were investigated in human faeces. While clinical use and prescriptions were the main exposure pathways for children, environmental media were the exposure pathway to adults. In addition, significant differences (P < 0.05) in antibiotic residues in human faeces were observed amongst various economic development levels, where human faeces from underdeveloped areas were mostly associated with higher levels of antibiotics. This study first to investigate the occurrence and distribution of typical antibiotics in the faeces of a Chinese population and thereby provide a reference for the intensive study of the effects and mechanisms of antibiotics on human gut microbiota.

Investigating the biodegradation of sulfadiazine in soil using Enterobacter cloacae T2 immobilized on bagasse

The application of the antibiotic sulfadiazine (SD) in veterinary medicine has created serious environmental issues due to its high mobility and non-degradability. A novel immobilized cell system has been developed and showed significant SD biodegradation potential in soil.

The accumulation and distribution of five antibiotics from soil in 12 cultivars of pak choi

There is a lack of understanding about the potential accumulation of antibiotics in plants exposed to low-dose contaminated soil. 12 Brassica rapa subsp. chinensis cultivars were used to investigate the different accumulation capacities of sulfamethoxypyridazine, tetracycline, ofloxacin, norfloxacin and difloxacin from the soil. The results showed a significant variation (p < 0.05) among the 12 cultivars in the accumulation of antibiotics. Cultivars Y1 and Y2 had the highest accumulation capacity with average concentrations of 3.26 and 3.00 μg kg^-1, respectively, while cultivars Y4 and Y9 had the lowest accumulation capacity with average concentrations of 0.83 and 0.89 μg kg^-1. The average antibiotic concentration in all edible part samples (2.74 μg kg^-1) of the treatment group was about 3.0-fold of that of the control group (0.93 μg kg^-1). The average bioconcentration factors of sulfamethoxypyridazine, tetracycline, ofloxacin, norfloxacin and difloxacin were 0.051, 0.031, 0.017, 0.036 and 0.034, respectively, indicating a higher uptake of sulfamethoxypyridazine compared to ofloxacin. And the mobility of antibiotics in soil is a main factor affecting the bioavailability for plants. The average concentration of antibiotics in edible parts of cultivar Y12 on the 25th and 45th day were 1.52 and 1.73 μg kg^-1 and that of the roots were 3.73 and 6.61 μg kg^-1, respectively. The concentrations of tetracycline and difloxacin in the edible parts and roots significantly increased with growing time, while the concentration of sulfamethoxypyridazine and ofloxacin changed little throughout the growing period. The potential risks of antibiotics in vegetables on human health cannot be ignored. Overall, attention should be paid to the translocation of antibiotics from soil to plants.

Antibiotic Residues in Food: Extraction, Analysis, and Human Health Concerns

The abundant use of antibiotics leads to antibiotic residues in frequently consumed foods. Residual antibiotics in food may have adverse effects on humans by directly causing disease via low-dose exposure and indirect harm via antibiotic resistance. However, the current methods for antibiotic extraction and analysis in food have not yet formed a uniform standard, and only a few data exist regarding the residual antibiotic condition in various types of foods. Hence, we review the literature since 2008 to summarize analytical methods and residue status of antibiotics in food. Then, we discuss the causes of antibiotic residues in food and the possible hazards to human health. We hope that the joint efforts of the scientific community and political circles will lead to the formation of a unified standard for the extraction and analysis of antibiotics in food, to allow for comprehensive monitoring of residual antibiotics and ensure human health.

Carbon and Tin-Based Polyacrylonitrile Hybrid Architecture Solid Phase Microextraction Fiber for the Detection and Quantification of Antibiotic Compounds in Aqueous Environmental Systems

In this study, the detection and quantification of multiple classes of antibiotics in water matrices are proposed using a lab-made solid phase microextraction (SPME) fiber coupled with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The lab-made fiber was prepared using a graphene oxide (G), carbon nanotubes (C), and titanium dioxide (T) composite, namely GCT, with polyacrylonitrile (PAN) as supporting material. The detected antibiotics were enrofloxacin, sulfathiazole, erythromycin, and trimethoprim. The custom-made fiber was found to be superior compared with a commercial C18 fiber. The excellent reproducibility and lower intra-fiber relative standard deviations (RSDs 1.8% to 6.8%) and inter-fiber RSDs (4.5% to 8.8%) made it an ideal candidate for the detection of traces of antibiotics in real environmental samples. The proposed validated method provides a satisfactory limit of detection and good linear ranges with higher (>0.99) coefficient of determination in the aqueous system. Application of the method was made in different real water systems such as river, pond and tap water using the standard spiking method. Excellent sensitivity, reproducibility, lower amount of sample detection and higher recovery was found in a real water sample. Therefore, the extraction method was successfully applied to the detection and quantification of multiple classes of antibiotics in different aqueous systems with satisfactory results.

A Simple, Sensitive, and Reliable Method for the Simultaneous Determination of Multiple Antibiotics in Vegetables through SPE-HPLC-MS/MS

Antibiotics, widely used in livestock breeding, enter the environment through animal manure because of incomplete absorption in animals, especially the farmland ecosystem. Therefore, antibiotics may be adsorbed by plants and even become hazardous to human health through the food chain. In this study, a simple, sensitive, and reliable method was developed for the simultaneous determination of eleven antibiotics, including four sulfonamides, two tetracyclines, three fluoroquinolones, tylosin, and chloramphenicol in different vegetable samples using SPE-HPLC-MS/MS. Vegetable samples were extracted by acetonitrile added with hydrochloric acid (125:4, v/v). The extracts were enriched by circumrotating evaporation, and then cleaned through SPE on a hydrophilic-lipophilic balance (HLB) cartridge. All compounds were determined on a C₁₈ reverse phase column through HPLC-MS/MS. The mean recoveries of 11 antibiotics from spiked samples of vegetables ranged from 71.4% to 104.0%. The limits of detection and quantification were 0.06⁻1.88 μg/kg and 0.20⁻6.25 μg/kg, respectively. The applicability of this technique demonstrated its good selectivity, high efficiency, and convenience by the analysis of 35 vegetable samples available from a vegetable greenhouse. Antibiotic residues in vegetables have aroused wide concern from the public. Therefore, standards should be established for antibiotic residues in vegetables to ensure food safety and human health.