Simultaneous Determination of Multiclass Pesticides and Antibiotics in Honey Samples Based on Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry

Effects of acephate and glyphosate-based agrochemicals on the survival and flight of Plebeia lucii Moure, 2004 (Apidae: Meliponini)

The conservation of terrestrial ecosystems depends largely on the preservation of pollinators, mainly bees. Stingless bees are among the main pollinators of native plants and crops in tropical regions, where they can be exposed to agrochemicals while foraging on contaminated flowers. In the present study, we investigated the effects on stingless bees of both a commonly used insecticide and herbicide in Brazil. Plebeia lucii Moure, 2004 (Apidae: Meliponini) foragers were orally chronically exposed to food contaminated with different concentrations of commercial formulations of the insecticide acephate or the herbicide glyphosate. Bee mortality increased with increasing agrochemical concentrations. Depending on its concentration, the acephate-based formulation reduced the lifespan and impaired the flight ability of bees. The glyphosate-based formulation was toxic only under unrealistic concentrations. Our results demonstrate that realistic concentrations of acephate-based insecticides harm the survival and alter the mobility of stingless bees. The ingestion of glyphosate-based herbicides was safe for forager bees under realistic concentrations.

A Review on Pretreatment and Analysis Methods of Polyether Antibiotics in Complex Samples

Polyether antibiotics (PAs) are the anti-coccidiosis drugs used for treating and preventing coccidiosis. Studies show the residues of these antibiotics in food cause adversities and threaten human health. PAs thus need robust, rugged, and accurate methods for their analysis. This review encompasses pretreatment and detection methods of PAs in diverse matrices since 2010. Both conventional and developed methods are part of the pretreatments, such as dispersive liquid-liquid microextraction, solid-phase extraction, solid-phase microextraction, solvent front position extraction, QuEChERS (Quick Easy Cheap Effective Rugged and Safe), supercritical fluid extraction, and others. The analysis methods involve liquid chromatography coupled with detectors, sensors, etc. The pros and cons of various techniques for PAs have been discussed and future tendencies are proposed.

Carbon Nanotube-Supported Dummy Template Molecularly Imprinted Polymers for Selective Adsorption of Amide Herbicides in Aquatic Products

In this study, a carbon nanotube (CNTs)-supported dummy template molecularly imprinted polymer (DMIPs) material was synthesized and utilized for the detection of amide herbicides in aquatic products via matrix solid-phase dispersion technology (MSPD). The DMIPs material was characterized, and its adsorption kinetics and isotherm were determined, the adsorption model was established, and the selective adsorption coefficient was calculated. The extract parameters of the method were optimized and successfully employed for the separation, analysis and detection of real samples, with satisfactory detection limits and linear ranges obtained. By comparing with other methods, the CNTs@DMIPs combined with MSPD technology established in our study can effectively solve false negative problems caused by insufficient destructive force, using dummy template molecules can also address the issue of false positives caused by template molecule leakage in molecular imprinting. Overall, the method is appropriate for the separation and detection of endogenous substances from highly viscous and poorly dispersed samples and is used as a routine detection tool in the aquaculture industry.

Tetracycline, Sulfonamide, and Erythromycin Residues in Beef, Eggs, and Honey Sold as "Antibiotic-Free" Products in East Tennessee (USA) Farmers' Markets

Foods that contain antibiotic residues have potential adverse health effects on consumers and provide selective pressure for the threat of antimicrobial resistance (AMR). This study's objective was to measure tetracycline, sulfonamide, and erythromycin residues in beef, eggs, and honey sold as "antibiotic-free" at farmers' markets in East Tennessee (East TN) in the United States (U.S.). Between July and September 2020, 36 "antibiotic-free" food products (9 beef, 18 egg, and 9 honey products) were purchased from East TN farmers' markets and tested for tetracycline, sulfonamide, and erythromycin residues using competitive enzyme-linked immunosorbent assays (cELISA). All beef, egg, and honey products had tetracycline residue; the median concentrations were 51.75, 30.25, and 77.86 µg/kg, respectively. Sulfonamide residue was present in every sample of beef. Of 18 eggs, 11 eggs had detectable sulfonamide residue; the median concentrations were 3.50 and 1.22 µg/kg in beef and eggs, respectively. Each sample of beef and honey contained erythromycin residue; the median concentrations were 3.67 and 0.68 µg/kg, respectively. Overall, the median concentrations of tetracycline, sulfonamide, and erythromycin residues were below the maximum residue levels (MRLs) set in the U.S. for beef and eggs. Thus, the beef and eggs sold as "antibiotic-free" in East TN farmers' markets can be considered safe for consumption. Safety determination for honey could not be made because MRLs have not been set for honey in the U.S. Because these residues should not be expected in "antibiotic-free" food products, it is important to further investigate the potential sources of these residues in these products.

Systemic assessment of the chiral insecticide pyriproxyfen in a citrus nectar source system: Stereoselective degradation, biological effect and exposure risk

BACKGROUND

Balancing the safety and efficiency of chiral pesticides can help protect pollinators. We evaluated the stereoselective behavior, bioactivity, toxicity and exposure risk of the chiral insecticide pyriproxyfen in a citrus nectar system.

RESULTS

Density functional theory (DFT) and ultra-performance liquid chromatography tandem mass spectroscopy (UPLC-MS/MS) were applied for absolute configuration appraisal and chiral analysis validation, respectively. The recoveries ranged from 72.3% to 100.5% with an relative standard deviation (RSD) ranging from 1.2% to 9.7%. In a field trial, we determined insecticide half-lives in citrus leaves and flowers, which were 7.0 and 8.6 days for R-(+)-pyriproxyfen, and 11.7 and 14.7 days for S-(-)-pyriproxyfen, respectively. We found that the bioactivity of R-(+)-pyriproxyfen was 3.39 and 2.37 times higher than S-(-)-pyriproxyfen against Unaspis yanonensis and Diaphorina citri nymphs, respectively. S-(-)-pyriproxyfen had 3.8 times higher acute toxicity than R-(+)-pyriproxyfen on Apis mellifera L., and its exposure risk was moderate based on the hazard quotient.

CONCLUSION

The phenomenon of stereoselective degradation and biological effect demonstrated that the high-risk stereoisomer of S-(-)-pyriproxyfen degraded more slowly than R-(+)-pyriproxyfen, but R-(+)-pyriproxyfen with better efficiency for target. Therefore, an increased duration of R-(+)-pyriproxyfen activity on citrus was beneficial for efficacy. Our results could guide the scientific application and evaluation of chiral pesticides on nectar plants. © 2022 Society of Chemical Industry.

Detection of nitrofurans residues in honey using surface-enhanced Raman spectroscopy

Residues of veterinary antibiotics in honey may be damaging to human health. Surface-enhanced Raman scattering spectroscopy (SERS) is an emerging technology widely applied in food safety. SERS has advantages of enabling fingerprint identification and fast detection, as well as does not require complex pretreatment. Considering the overuse of nitrofurans in honeybee breeding, SERS combined with spectral preprocessing was used to detect nitrofurantoin in honey. By using standardized experimental procedures and improved spectral correction methods, the lowest detection limit of nitrofurantoin was 0.1321 mg/kg. A good linear relationship in the partial least squares regression model was found among spiked samples, which allowed prediction of nitrofurantoin content in honey sample ( R C 2 $R_C^2$ =  0.9744; R P 2 $R_P^2$ =  0.976; RMSECV = 1.0353 mg/kg; RMSEP  =  0.9987 mg/kg). Collectively, these results reliably demonstrated that quantification is more accurate when spectral preprocessing is better controlled. Therefore, this study indicates that SERS could be further implemented in fast and onsite detection of nitrofurantoin in honey for improved food safety. PRACTICAL APPLICATION: This article presents a novel SERS-based method for the rapid detection of nitrofurantoin residues in honey. The original spectra were corrected by multiple linear regression based on the fitting baseline. This study aims to develop a rapid onsite detection method for toxic hazardous substance residues in food.

Antibiotic Use in Livestock and Residues in Food-A Public Health Threat: A Review

The usage of antibiotics has been, and remains, a topic of utmost importance; on the one hand, for animal breeders, and on the other hand, for food safety. Although many countries have established strict rules for using antibiotics in animal husbandry for the food industry, their misuse and irregularities in compliance with withdrawal periods are still identified. In addition to animal-origin foods that may cause antibiotic residue problems, more and more non-animal-origin foods with this type of non-compliance are identified. In this context, we aim to summarize the available information regarding the presence of antibiotic residues in food products, obtained in various parts of the world, as well as the impact of consumption of food with antibiotic residues on consumer health. We also aim to present the methods of analysis that are currently used to determine antibiotic residues in food, as well as methods that are characterized by the speed of obtaining results or by the possibility of identifying very small amounts of residues.

Application of a Validated Method for the Identification and Quantification of Mycotoxins in Wines Using UPLC-MS/MS

The aim of the present study was to develop a rapid, simple and reliable method for the identification and quantification of six mycotoxins in wine using liquid chromatography with electrospray ionization tandem mass spectrometry. The analytical method was fully validated, and calibration curves were made with correlation coefficients >0.9970. A short analysis time and acceptable extraction efficiency were achieved by a direct extraction method of analytes (ochratoxin A, aflatoxin B1, B2, G1, G2 and Zearalenone) with acetonitrile. LOD values were from 0.03 to 0.27 μg kg−1, and LOQ values were from 0.08 to 0.81 μg kg−1, with recoveries at various values from 77 to 108%. The expanded uncertainty was 5–21% expressed at a coverage level of k = 2, at a confidence level of approximately 95%. The performance criteria of the method were fully met according to European legislation (EC) 401/2006. The method was successfully applied to wine samples from Cyprus. The method was simple, low cost, quick, accurate, and sensitive.

Detection of Antibiotic Residues in Blossom Honeys from Different Regions in Turkey by LC-MS/MS Method

In the present study, a total of 80 commercial blossom honey samples were obtained from local markets in Ankara, Turkey. These honeys were analyzed for 35 important and risky antibiotics (sulfonamide, tetracycline, macrolide, cephalosporin, aminoglycoside, quinolone, nitrofuran, chloramphenicol, and anthelmintic groups) by the LC-MS/MS multi-antibiotic method. In addition to these analyses, pH measure, moisture, and electrical conductivity were determined in these honey samples. Finally, seven out of 35 antibiotic residues investigated in the honeys were positive. The most frequently detected antibiotics in the analyzed samples were dihydrostreptomycin, streptomycin, erythromycin, sulfadimidine (sulfamethazine), and enrofloxacin as 58.75%, 22.5%, 13.75%, 10%, and 2.5%, respectively. Tetracycline and doxycycline were detected in only one sample. The pH, moisture, and electrical conductivity values of the honey samples were determined as between pH 3.78 and 5.41, 17.48 and 18.03%, and 0.25 and 0.47 mS/cm, respectively. In terms of food safety and human health, it is very important to monitor the residues of these pharmacologically active substances with analytical methods.

Honey on Basketball Players' Physical Recovery and Nutritional Supplement

Sports injury is a subject that every athlete will face, and it is the easiest to happen in training and competition, especially for basketball players. Moreover, the excessive fatigue caused by sports not only reduces the person's ability to play sports, but also it reduces the person's participation in normal training and competition. Sugar and fat play a dominant role in energy metabolism, while protein only plays an auxiliary role. For competitive sports, sugar is the most important energy, and the main components of honey are glucose and fructose. Therefore, this paper attempts to explore the effect of honey on the physical recovery and nutritional supplement of basketball players. In this paper, 10 basketball players in our city were selected as the experimental objects and the data of their physiological and biochemical indexes were analyzed. The results showed that the average hemoglobin of the experimental group decreased from 14.45 g·100 ml-1 in the first week to 13.23 g·100 ml-1 in the second week, increased to 14.25·100 ml-1 in the third week, and increased to 15.79.100 ml-1 in the fourth week. Adding honey can improve the content of HB and CK of basketball players in higher vocational colleges and reduce the increase of BUN, to slow down fatigue and accelerate the speed of physical recovery.

Comparison of the Biological Potential and Chemical Composition of Brazilian and Mexican Propolis

Propolis is a resinous substance collected by bees from plants and its natural product is available as a safe therapeutic option easily administered orally and readily available as a natural supplement and functional food. In this work, we review the most recent scientific evidence involving propolis from two countries (Brazil and Mexico) located in different hemispheres and with varied biomes. Brazil has a scientifically well documented classification of different types of propolis. Although propolis from Brazil and Mexico present varied compositions, they share compounds with recognized biological activities in different extraction processes. Gram-negative bacteria growth is inhibited with lower concentrations of different types of propolis extracts, regardless of origin. Prominent biological activities against cancer cells and fungi were verified in the different types of extracts evaluated. Antiprotozoal activity needs to be further evaluated for propolis of both origins. Regarding the contamination of propolis (e.g., pesticides, toxic metals), few studies have been carried out. However, there is evidence of chemical contamination in propolis by anthropological action. Studies demonstrate the versatility of using propolis in its different forms (extracts, products, etc.), but several potential applications that might improve the value of Brazilian and Mexican propolis should still be investigated.

Determination of Avermectins Residues in Soybean, Bean, and Maize Using a QuEChERS-Based Method and Ultra-High-Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry

Soybean, maize, and bean are crops of great economic importance, but in recent years have suffered with infestations of the caterpillar Helicoverpa armigera, with the main reason being the resistance of this pest to most pesticides. Avermectin emamectin benzoate was recently released to control this pest. Other avermectins, like abamectin, doramectin, eprinomectin, and ivermectin are used in large scale because they potent acaricidal, anthelmintic, and insecticidal activities. Thus, a simple and fast method for the determination of avermectins in these crops based on a quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction procedure and ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) analysis was developed and validated. For extraction, water followed by acetonitrile:isopropanol and a partition step with salts was stablished. With the clean-up step using activated EMR-Lipid, limits of detection of 1.2 μg kg−1 for abamectin, doramectin, emamectin benzoate, and ivermectin, and of 2.4 μg kg−1 for eprinomectin were achieved. The validation showed satisfactory results and the method was successfully applied to commercial samples, indicating that it is suitable for routine analysis.

Meliponinae and Apis mellifera honey in southern Brazil: Physicochemical characterization and determination of pesticides

This study evaluated the physicochemical parameters and the occurrence of pesticides in multi-flower honey produced by six species of Meliponinae and Apis mellifera and collected in different seasons, floral species and sites in southern Brazil. Meliponinae honey were found to exhibit higher moisture, free acidity and sucrose concentration and lower concentration of reducing sugars than the standard of Apis mellifera honey in Brazil. Regarding Apis mellifera honey, reducing sugars and sucrose did not comply with the legislation. The Principal Component Analysis (PCA) showed that most of the composition variability was defined by free acidity, moisture, soluble solids, fructose, glucose, and reducing sugars. Determination of pesticides was carried out by the citrate QuEChERS method and gas chromatography tandem mass spectrometry (GC-MS/MS). However, no pesticide residues at concentrations above the limit of quantification were found in the twenty honey samples. Results show that this region has the potential to produce honey.

Comparison of Sin-QuEChERS Nano and d-SPE Methods for Pesticide Multi-Residues in Lettuce and Chinese Chives

In this study, a new rapid cleanup method was developed for the analysis of 111 pesticide multi-residues in lettuce and Chinese chives by GC-MS/MS and LC-MS/MS. QuEChERS (quick, easy, cheap, effective, rugged and safe)-based sample extraction was used to obtain the extracts, and the cleanup procedure was carried out using a Sin-QuEChERS nano cartridge. Comparison of the cleanup effects, limits of quantification and limits of detection, recoveries, precision and matrix effects (MEs) between the Sin-QuEChERS nano method and the classical dispersive solid phase extraction (d-SPE) method were performed. When spiked at 10 and 100 μg/kg, the number of pesticides with recoveries between 90% to 110% and relative standard deviations < 15% were greater when using the Sin-QuEChERS nano method. The MEs of Sin-QuEChERS nano and d-SPE methods ranged between 0.72 to 3.41 and 0.63 to 3.56, respectively. The results verified that the Sin-QuEChERS nano method was significantly more effective at removing pigments and more convenient than the d-SPE method. The developed method with the Sin-QuEChERS nano cleanup procedure was applied successfully to determine pesticide residues in market samples.

Effective methods for the determination of triphenyltin residues in surface water and soil samples by high-performance liquid chromatography with tandem mass spectrometry

Monitoring of triphenyltin (TPhT) in the environment, particularly to control its misuse in agriculture, is of great importance because of its high toxicity. In this work, methods for determination of TPhT residues in surface water and soil samples by liquid chromatography with tandem mass spectrometry (LC-MS/MS) were developed and validated. Different sample volumes and pH and elution solvent types and volumes were evaluated for solid phase extraction (SPE) of TPhT in surface water samples. The optimized conditions were 500 mg sorbent Strata C18-E, 100 mL of the sample, pH adjusted to 9.0 and 1 mL of methanol containing acetic acid as the eluent. For a 10 g soil sample, the extraction was established using a modified QuEChERS method with 10 mL of acidified acetonitrile followed by a clean-up step by dispersive solid phase extraction (dSPE) with C18. A full factorial 23 design of experiments was applied to optimize the sample preparation method for soil samples. Practical method limits of quantification were 0.1 μg L-1 and 10 μg kg-1 for surface water and soil samples, respectively. Satisfactory accuracy, with recoveries from 86 to 107% for surface water and 72 to 87% for soil samples, as well as good precision, with an overall relative standard deviation (RSD) from 3 to 8% was observed. The validated methods were applied to real samples and some residues of TPhT were found, especially in soil samples (30 to 190 mg kg-1), indicating the suitability for routine analysis.

Response Surface Optimization of an Extraction Method for the Simultaneous Detection of Sulfamethoxazole and 17β-Estradiol in Soil

Antibiotics and hormones widely exist in fertilizers and manures, which are excessively used in agriculture and animal husbandry. Considering their potential harm to the environment and human health, the detection of antibiotics and hormones has become a necessity. However, current methods find it difficult to simultaneously extract and detect antibiotics and hormones in soil and to maintain a high level of accuracy and a low cost. In this study, a straightforward, convenient, and simultaneous extraction and detection method of a representative antibiotic (sulfamethoxazole, SMZ) and hormone (17β-Estradiol, E2) in soil has been established. Ultrasound-assisted extraction (UAE) was used in the pretreatment process and high-performance liquid chromatography with the ultraviolet detector (HPLC-UV) method was then chosen in the detection process. By means of single factors and response surface experiments, optimal extraction conditions were a 41-mL buffer solution (pH 4.27) mixed with 1 g of soil sample, an ultrasonication time of 36 min, an ultrasonication temperature of 25 °C, and two extraction cycles. The detection limits of 0.3–10 μg/kg and quantification limits of 1–30 μg/kg have been obtained. Finally, the optimized simultaneous extraction and detection method was validated by three different real soil samples with recoveries ranging from 79.49% to 86.47%.

Comprehensive tropane alkaloids analysis and retrospective screening of contaminants in honey samples using liquid chromatography-high resolution mass spectrometry (Orbitrap)

A wide-scope analytical method was developed and validated for the determination of tropane alkaloids (TAs) in honey samples. A simple and fast extraction procedure, using a mixture of methanol/water/formic acid (75/25/0.4, v/v/v) as extraction solvent, followed by a clean-up with graphitized black carbon (GBC) and magnesium sulphate was optimized, and compounds were analysed by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS-Orbitrap). Validation of the proposed method provided adequate linearity (R² > 0.99), trueness (recoveries 71-120%) and precision (relative standard deviation, RSD ≤ 20.1%), with limits of quantitation (LOQs) at 20 µg/kg (except anisodamine and scopolamine at 40 µg/kg) and a significant matrix effect (≤-50%). Nineteen honey samples were analysed, but only one was positive, containing 27 µg/kg of scopolamine. Additionally, a post-targeted screening was performed, and 47% of samples were contaminated with different herbicides, insecticides and veterinary drugs. Therefore, the proposed analytical method is a powerful tool for both targeted TAs and post-targeted contaminant analyses.

Overview of Analytical Methods for the Determination of Neonicotinoid Pesticides in Honeybee Products and Honeybee

Neonicotinoid pesticides are widely applied for controlling pests in a variety of agriculture crops. Due to the systemic distribution in plants, neonicotinoid pesticides have been found in nectar and pollen, which are the main source of food for the important pollinator honeybee. The risk of neonicotinoid residues in honeybee products and honeybee has caused great attention since their impacts on the environment, ecology, and food safety issues. These concerns require the accurate and sensitive determination of neonicotinoids and their metabolites in the honeybee products and honeybee. Since the trace residue level of neonicotinoid and the complexity of the samples, analysis of neonicotinoid targets in these important matrices is still a great challenge. The present review provides general overview of analytical methods for the determination of neonicotinoid pesticides and their metabolites in honeybee products and honeybee.

Epigallocatechin gallate prevents senescence by alleviating oxidative stress and inflammation in WI-38 human embryonic fibroblasts

Increased levels of oxidative stress and inflammation are the underlying mechanisms behind the aging process and age-related diseases. The purpose of our research is to explore whether epigallocatechin gallate (EGCG) can extend replicative life span by preventing the oxidative stress and inflammatory effects of WI-38 fibroblasts and the involved mechanisms in vitro. WI-38 cells were treated with different concentrations of EGCG (0, 25, 50 and 100 μM) at population doubling (PD) 25. At late-stage cells, we determined the age-associated genes with signaling through transcriptome sequencing. The expression profile of the targets in WI-38 fibroblasts was confirmed by bioinformatics analysis, qPCR and western blot. We found that EGCG markedly decreased reactive oxygen species (ROS), and inflammation factors, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and significantly increased cell proliferation at PD 35 and 45. EGCG treatments significantly decreased p53 and retinoblastoma (Rb) expressions, markedly increased p-Rb and E2F2 expressions as well as antioxidant enzymes and superoxide dismutase (SOD) 1 and SOD2 content, and obviously decreased the expressions of inflammation factors IL-32, TNF-α expressions at PD 45 WI-38 cells. Moreover, the effects were changed by EGCG treatment by p53 siRNA or overexpression. These findings in our studies reveal that EGCG treatments improved senescence and enhanced the replicative life span through alleviating oxidative stress and inflammation in WI-38 fibroblasts.

Matrix-Induced Sugaring-Out: A Simple and Rapid Sample Preparation Method for the Determination of Neonicotinoid Pesticides in Honey

In the present work, we developed a simple and rapid sample preparation method for the determination of neonicotinoid pesticides in honey based on the matrix-induced sugaring-out. Since there is a high concentration of sugars in the honey matrix, the honey samples were mixed directly with acetonitrile (ACN)-water mixture to trigger the phase separation. Analytes were extracted into the upper ACN phase without additional phase separation agents and injected into the HPLC system for the analysis. Parameters of this matrix-induced sugaring-out method were systematically investigated. The optimal protocol involves 2 g honey mixed with 4 mL ACN-water mixture (v/v, 60:40). In addition, this simple sample preparation method was compared with two other ACN-water-based homogenous liquid-liquid extraction methods, including salting-out assisted liquid-liquid extraction and subzero-temperature assisted liquid-liquid extraction. The present method was fully validated, the obtained limits of detection (LODs) and limits of quantification (LOQs) were from 21 to 27 and 70 to 90 μg/kg, respectively. Average recoveries at three spiked levels were in the range of 91.49% to 97.73%. Precision expressed as relative standard deviations (RSDs) in the inter-day and intra-day analysis were all lower than 5%. Finally, the developed method was applied for the analysis of eight honey samples, results showed that none of the target neonicotinoid residues were detected.

Optimization of the Data Treatment Steps of a Non-targeted LC-MS-Based Workflow for the Identification of Trace Chemical Residues in Honey

Non-targeted screening (e.g., suspected-target) is emerging as an attractive tool to investigate the occurrence of contaminants in food. The sample preparation and instrument analysis steps are known to influence the identification of analytes with non-targeted workflows, especially for complex matrices. However, for methods based on mass spectrometry, the impact of the post-analysis data treatment (e.g., feature extraction) on the capacity to correctly identify a contaminant at trace level is currently not well understood. The aim of the study was to investigate the influence of seven post-analysis data treatment parameters on the non-targeted identification of trace contaminants in honey using high-performance liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS). Seven compounds reported as veterinary drugs for honeybees were applied as model compounds. Among the parameters studied, the expansion window for chromatogram extraction and the average scans included in the spectra influenced significantly the identification process results. The optimized data treatment was applied to the non-targeted screening of veterinary drugs, pesticides, and other contaminants in 55 honey samples as a proof of concept. Among the 43 compounds included in a library of honey-related compounds that was used for screening, eight compounds were tentatively identified in at least one honey sample. The tentative identity of two of these compounds (tylosin A and hydroxymethylfurfural) was further confirmed with analytical standards. Graphical Abstract.

Comprehensive analysis of insecticides in melliferous weeds and agricultural crops using a modified QuEChERS/LC-MS/MS protocol and of their potential risk to honey bees (Apis mellifera L.)

The risk of exposure of honey bees to the presence of insecticides in melliferous plants is higher than previously reported. Therefore, monitoring insecticide residues in these plants is of great importance to honey bee safety. A novelty of the present research was the development of an innovative procedure for determination of residues of 142 insecticides in weeds and agricultural crops among melliferous plants. Phacelia, buckwheat, rape, common dandelion, cornflower and clover were selected for testing. Samples were extracted via QuEChERS. Two single sorbents (Z-Sep and Chitosan) and two combinations of sorbents (PSA/C18/ENVI-Carb/MgSO₄, PSA/GCB/MgSO₄) were tested. The matrix effect was applied as the main criterion for assessment of the method's effectiveness. The best sorbent for preparation of: (i) common dandelion samples was PSA/GCB/MgSO₄, (ii) rape, cornflower and clover samples - PSA/C18/ENVI-Carb/MgSO₄ sorbent and (iii) phacelia and buckwheat samples - Z-Sep sorbent. The developed procedure was applied for quantification of insecticide residues in 41 melliferous plant samples to estimate exposure of honey bees to pesticides through calculation of the hazard quotient (HQ). In total, 12 different insecticides were detected. The presence of neonicotinoid insecticides was found 7 times. The residues most frequently identified in melliferous plants were deltamethrin, dimethoate, and its metabolite, omethoate. An increased insecticide risk to honey bees was found for 4.9% and 9.8% of samples, for the oral and contact dose, respectively. This is why the hazard of melliferous plant residues was considered elevated for honey bees. The results clearly demonstrated that the approach developed provides reliable, simple and rapid determination of insecticides in melliferous plants, which is of great importance to honey bee safety.

Direct injection high performance liquid chromatography coupled to data independent acquisition mass spectrometry for the screening of antibiotics in honey

The targeted analysis of veterinary drug residues in honey traditionally involves a series of extraction and purification steps prior to quantification with high performance liquid chromatography coupled to high resolution or tandem mass spectrometry. These steps, designed to separate the target analytes from interferences, are generally time-consuming and costly. In addition, traditional cleanup steps are likely to eliminate other compounds whose analysis could prove decisive in current or future assessment of the honey sample. Alternatively, direct injection without complex sample preparation steps has been introduced for the fast analysis of trace compounds in environmental and food matrices. The aim of this study was to develop a rapid method for the targeted analysis of 7 key veterinary drug residues in honey based on direct injection high performance liquid chromatography coupled to quadrupole time-of-flight, while simultaneously recording data-independent MS/MS (e.g. All Ions MS/MS data) for future re-examination of the data for other purposes. The new method allowed for the detection of the target residues at levels approximately 20-100 times lower than current regulatory limits, for a total analysis time of about 45 min. The recoveries (103-119%), the linearity (R ≥ 0.996) and the repeatability (RSD ≤ 7%) were satisfactory. The method was then applied to 35 honey samples from the Canadian market. Residues of tylosin A, tylosin B, sulfamethazine and sulfadimethoxine were detected in 6, 9, 6 and 23% of the samples respectively, at levels below the regulatory limits in Canada. The possibility of adding a hydrolysis step to study sulfonamides in honey was tested, which provided good results for this family of compounds but lead to degradation of some of the other analytes. Finally, the non-targeted identification of several compounds was demonstrated as a proof of concept of future re-examination of All Ions MS/MS data. This paper illustrates the capacity of this novel method to combine targeted and non-targeted screening of chemical residues in honey.

A spherical metal-organic coordination polymer for the microextraction of neonicotinoid insecticides prior to their determination by HPLC

The authors describe a new spherical metal-organic coordination polymer (MOCP) for use as an adsorbent in solid-phase microextraction (SPME). By applying the ions Co(II), Fe(II), Cu(II), and Zn(II) in these polymers, MOCP with different morphology were obtained. The respective coatings for SPME display different extraction efficiency towards neonicotinoid insecticides (neo-nics). The Co(II)@MOCP coating displays an improved extraction capability for neo-nics when compared to the four commercially available coatings studied. Following extraction with the Co(II)@MOCP-coated fiber, the neo-nics were eluted using 1 mL of trifluoroacetic acid/acetonitrile solution and quantified by high performance liquid chromatography. The method, when applied to spiked honey samples, has good linearity (0.5-600 μg kg^-1) and a low limit of detection (0.05-0.15 μg kg^-1). The precision (n = 6) for a single fiber was in the range of 3.6-8.3%. The reproducibility (for n = 5) from fiber-to-fiber ranges between 5.4 and 8.8%. The Co(II)@MOCP-coated fiber can be reused more than 80 times without any apparent reduction in its performance. In addition, the relative recoveries from spiked honey samples are very good (91.5%-103.5%). Graphical abstract A spherical metal-organic coordination polymer (MOCP) was synthesized under the regulation of Co(II) and used for the solid-phase microextraction (SPME) of neonicotinoid insecticides found in honey.

Sulfonamide Residues: Honey Quality in the Czech Market

In this study, we determined four sulfonamide compounds (sulfadiazine, sulfadoxine, sulfamethoxazole, and sulfathiazole) in honey marketed in the Czech Republic (Brno). The content of these compounds was monitored in 50 honeys with different botanical and geographical origin. Preanalytical treatment included acidic hydrolysis with 10% trichloroacetic acid (TCA) and double extraction with acetonitrile and dichloromethane. Chromatographic analysis was performed by ultraperformance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) using a triple quadrupole (QqQ) in positive ionization mode (ESI+). For separation, the mobile phase was a 0.05% aqueous solution of formic acid (A) and 0.05% formic acid in methanol (B) with a gradient elution of 0–3 minutes: 10% B; 3–3.6 min: 90% B; and 3.6–5 min: 10% B, flow rate 0.30 ml/min. Three positive samples (6%) were found containing sulfadiazine (232.88 and 618.87 μg/kg) and sulfamethoxazole (62.64 μg/kg). According to the country of origin, two of these honeys were from European Union (EU) countries, and one was labeled as a blend of honey from EU and non-EU countries.

Dissipation behaviour and dietary risk assessment of boscalid, triflumizole and its metabolite (FM-6-1) in open-field cucumber based on QuEChERS using HPLC-MS/MS technique

BACKGROUND

To resist plant diseases, boscalid and triflumizole have been applied to cucumbers frequently. However, the residue and dietary risk assessment of these fungicides in cucumber should be given attention for food safety.

RESULTS

An effective and highly sensitive method based on the liquid chromatography-tandem mass spectrometry technique for simultaneous multidetermination of boscalid, triflumizole and its metabolite (FM-6-1) in a cucumber ecosystem was established and validated. Field experiments were conducted in three different locations, where boscalid and triflumizole (35% suspension concentration) were applied at 253 g of active ingredient (a.i.) per hectare (the recommended high dosage) and 379.5 g a.i. ha^-1 (1.5 times the recommended high dosage) in each location. The limits of quantification and the limits of detection of the proposed method ranged from 0.01 to 0.05 mg kg^-1 and 3.9 × 10^-5 to 7.5 × 10^-4 mg L^-1 respectively. The mean recoveries and relative standard deviations of these compounds were 80-105% and 1.0-6.1% respectively. The dissipation dynamics of compounds followed pseudo-first-order kinetic models remarkably, with a half-value period of 2.3-40.8 days. The residues of boscalid and triflumizole in cucumber at harvest were below 0.66 mg kg^-1 and 0.07 mg kg^-1 respectively. The results of the dietary risk assessments have shown a low dietary risk of compounds in cucumber with hazard ratios <1 and hazard index <1.

CONCLUSION

These results from the experiments are the most important for putting a guide on reasonable usage of these fungicides under the open-field conditions in China. © 2018 Society of Chemical Industry.

Chemiluminescence determination of furazolidone in poultry tissues and water samples after selective solid phase microextraction using magnetic molecularly imprinted polymers

For the first time, a selective extraction method combined with chemiluminescence was developed for the determination of FZD in various samples.

TD-M06-2X insights into the absorption and emission spectra of dichlorvos and its molecularly imprinted recognition by methacrylic acid

The absorption and emission spectra of dichlorvos and the dichlorvos-MAA complex in methanol, water, and chloroform in the molecularly imprinted recognition were investigated systematically. The M06-2X results revealed that: 1) the hydroxyl groups in polar solvents such as methanol and water may markedly influence the weak interactions, and then alter the adsorption and emission spectra; 2) the electronic excitation in absorption spectra of dichlorvos is dominated by the configuration HOMO → LUMO, but in the most stable dichlorvos-MAA it becomes the ππ* excitation of HOMO → LUMO + 1; 3) Mulliken charges reveal that dichlorvos almost dissociates to Cl^- and a cation in its S₁ excitation state; 4) the phosphorescence spectra of dichlorvos-MAA are relatively weak. Graphical Abstract The absorption and emission spectra of dichlorvos and the dichlorvos-MAA complex in the molecularly imprinted recognition of dichlorvos were investigated systematically in methanol, water, and chloroform as solvents.