Comprehensive qualitative and quantitative determination of pesticides and veterinary drugs in honey using liquid chromatography-Orbitrap high resolution mass spectrometry

Fungicide Metabolite MS2 Spectral Libraries for Comprehensive Human Biomonitoring

Fungicides undergo rapid metabolism and are excreted in the urine. There are few methods for screening these ubiquitous compounds, which have a high potential for human exposure. High-resolution mass spectrometry (HRMS) is a suitable technique to assess fungicide exposures; however, there is a lack of spectral libraries for fungicide annotation and in particular for downstream metabolites. We created spectral libraries for 32 fungicides for suspect screening. Fungicide standards were administered to mice, and 24-h urine was analyzed using hydrophilic interaction and reversed-phase chromatography coupled to hybrid quadrupole-orbitrap mass spectrometry. Suspect metabolite MS2 spectra for library creation were selected based on the ratio of exposed-to-control mouse urine. MS2 libraries were applied to urine collected from female university students (n = 73). Several tetraconazole and tebuconazole metabolites were detected in 3% (2/73) of the samples. The creation of comprehensive suspect screening MS2 libraries is a useful tool to detect fungicide exposure for human biomonitoring.

Mass Spectrometry Characterization of Honeydew Honey: A Critical Review

Honeydew honey is produced by bees (Apis mellifera) foraging and collecting secretions produced by certain types of aphids on various parts of plants. In addition to exhibiting organoleptic characteristics that distinguish them from nectar honey, these honeys are known for their functional properties, such as strong antioxidant and anti-inflammatory activities. Despite their importance, they remain poorly characterized in comparison with flower honeys, as most studies on this subject are not only carried out on too few samples but also still focused on traditional chemical-physical parameters, such as specific rotation, major sugars, or melissopalynological information. Since mass spectrometry has consistently been a primary tool for the characterization and authentication of honeys, this review will focus on the application of these methods to the characterization of the minor fraction of honeydew honey. More specifically, this review will attempt to highlight what progress has been made so far in identifying markers of the authenticity of the botanical and/or geographical origin of honeydew honeys by mass spectrometry-based approaches. Furthermore, strategies devoted to the determination of contaminants and toxins in honeydew honeys will be addressed. Such analyses represent a valuable tool for establishing the level of food safety associated with these products. A critical analysis of the presented studies will identify their limitations and critical issues, thereby describing the current state of research on the topic.

Developing a novel magnetic organic polymer for selective extraction and determination of 16 macrolides in water and honey samples

A novel magnetic organic polymer Fe3O4@SiO2@Tb-PDAN was designed and synthesized, which was used as an adsorbent for magnetic solid-phase extraction (MSPE) of 16 macrolides (MALs) in water and honey. The synthesized adsorbent was characterized using techniques including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Then several parameters of the extraction process were further optimized. Under the optimized conditions, an MSPE-LC-MS/MS method was established for extraction and determination of 16 MALs, which showed good linearity (r ≥ 0.999), low limits of detection (0.001-0.012 μg L-1 for water and 0.001-0.367 μg kg-1 for honey) and satisfactory recoveries (70.02-118.91%) with the relative standard deviations (RSDs) lower than 10.0%. This established method was then successfully applied to detect MALs in real samples, which suggested that Fe3O4@SiO2@Tb-PDAN was a potential magnetic adsorbent for efficient extraction and analysis of MALs.

Targeted Analysis of Veterinary Drugs in Food Samples by Developing a High-Resolution Tandem Mass Spectral Library

Veterinary drug residues present in foods can pose severe health threats to the population. The present study aims to develop a high-resolution mass spectral library of 158 veterinary drugs of 16 different classes for their rapid identification in food samples through liquid chromatography-high-resolution electrospray ionization-tandem mass spectrometry (LC-HR-ESI-MS/MS). Standard drugs were pooled according to their log P values and exact masses before analysis. Spectra were collected at system automated collision energy, i.e., of 25-60 eV and four predetermined collision energies (10, 20, 30, and 40 eV) for each compound using a schedule precursor list of [M + H]+, [M + Na]+, and [M + NH4]+ ions. The utility of the developed database was checked by analyzing food samples. A total of 17 veterinary drugs based on the reference standard retention times (RTs), HR-MS spectra, and MS/MS spectra were identified in the analyzed samples. Moreover, five veterinary drugs were selected for quantitative analysis, including doxycycline hyclate, lincomycin, sulfasalazine, moxifloxacin, and diphenoxylate, using liquid chromatography-ion trap mass-spectrometry (LC-IT-MS). Concentrations of the drug were obtained to vary from 0.0805 to 0.9731 mg/kg in food samples and were found to be exceeded in most of the cases as per the maximum residue levels described by Food and Agriculture Organization (FAO)/World Health Organization (WHO). The MS data were submitted to the MetaboLights online database (MTBLS2914). This study will help in the high-throughput screening of multiclass veterinary drugs in foodstuffs.

Optimisation and implementation of QuEChERS-based sample preparation for identification and semi-quantification of 694 targeted contaminants in honey, jam, jelly, and syrup by UHPLC-Q/ToF high-resolution mass spectrometry

A screening and semi-quantitative method was developed for the analysis of 694 various contaminants in honey, jam, jelly and syrup samples by ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry. Sample preparation, which was optimised using split factorial design, was based on acetate-buffered version of QuEChERS, followed by a clean-up step and a concentration step to enhance sensitivity of analytes. The method was validated according to SANTE/11312/2021 guidelines. The screening detection and limits of identification were established as being less than or equal to 0.05 mg.kg^-1 for 89% and 74% of the contaminants, respectively. The validated screening method was applied to 50 concentrated sugary products. Overall, 46% of the samples were positive to pesticide residues. Most of the positive samples (78%) contained mixtures of pesticide residues. Three time-and-cost saving convenient strategies suitable for high-throughput analysis were proposed for the targeted semi-quantification of the previously contaminants identified in samples.

Self-templating hydrothermal synthesis of carbon-confined double-shelled Ni/NiO hollow microspheres for diphenylamine detection in fruit samples

Toxic substances, such as heavy metals, toxins, pesticides, pathogens, and veterinary drug residues in food are hazardous to consumer health. The variety and quantity of food consumption have increased owing to developments in the agricultural and food industries. Food safety has a substantial socioeconomic impact, and an increasing number of consumers have become aware of its importance. Therefore, simple and cost-effective analytical methods are required to quantify the safety of preservatives. Herein, we report an electrochemical method using double-shelled carbon-confined Ni/NiO (C@Ni/NiO) hollow microspheres to detect diphenylamine (DPA). The microspheres were synthesized by a self-templating hydrothermal method followed by calcination. The hydrothermal temperature and precursor ratio were optimized systematically to prepare double-shelled C@Ni/NiO hollow microspheres. The excellent electrocatalytic activity and electron transport properties of a C@Ni/NiO-modified glassy carbon electrode (GCE) were exploited in the electrochemical oxidation of DPA. Interestingly, the engineered C@Ni/NiO/GCE has a wide dynamic linear range (0.02-473 μM) and a DPA detection limit of 0.007 μM. In addition, the DPA sensor exhibited good selectivity, reproducibility, repeatability, and stability. The practical feasibility of the DPA sensor was evaluated in fruit samples (sweet tomatoes, apples, and red grapes), with considerable recovery.

Evaluation of an alternative sorbent for passive sampling of the herbicides 2,4-D and Dicamba in the air

The present study aimed to evaluate the Strata-X^® sorbent, commonly used in cartridges, through analysis by high-performance liquid chromatography coupled with mass spectrometry. Due to the different physical-chemical characteristics of the compounds, different conditions of chromatography and mass analysis were necessary. The developed methods were validated in terms of selectivity, linear range, linearity (coefficient of determination, r²), the limit of detection (LOD), the limit of quantification (LOQ), accuracy (recovery, %), and precision (RSD, %). The results allowed us to select efficient extraction methods, using methanol acidified to pH 2 with formic acid, to elute the herbicides 2,4-D and dicamba in both sorbent materials. Besides, the Strata-X^® sorbent was efficient in the sorption of analytes; thus, we indicate it for potential use in air sampling as an alternative to XAD-2.

Fast and simultaneous analysis of carbamate pesticides and anticoagulant rodenticides used in suspected cases of animal poisoning

Carbamate pesticides (CBs) are reported as one of the main causes of intentional or accidental poisoning of animals. Anticoagulant rodenticides (ARs) form the main class of poisons implicated in analyzed poisoned baits. These two groups of pesticide compounds include multiple substances, and thus, the development of a simple and rapid multiclass/multiresidue analytical method for simultaneous identification of both toxicant classes should be a useful strategy for analytical laboratories to reduce analysis time and cost. The present study aimed to elaborate and validate a rapid method to simultaneously determine 11 CBs and 8 ARs in samples of real matrices (bait, stomach content, and liver) from suspected animal poisoning cases. QuEChERS sample treatment and liquid chromatography coupled to hybrid high resolution mass spectrometry were used. The method resulted in good linearity (R2 ≥ 0.98) for all compounds, recovery was between 70% and 120% for CBs and 40-90% for ARs, and precision was ≤ 20% for all compounds. The method was successfully applied to the analysis of 871 real samples originating from suspected cases of animal poisoning, collected from April 2019 to October 2020. Furthermore, full scan dependent data acquisition allowed qualitative retrospective data analysis of an additional 15 compounds outside the scope of the method to be performed; these compounds could potentially be involved in unresolved poisoning cases.

Magnetic molecularly imprinted polymer nanoparticles for the extraction and clean-up of thiamethoxam and thiacloprid in light and dark honey

In this work, new selective and sensitive dual-template molecularly imprinted polymer nanoparticles (MIPs) were synthesized and characterized. Sorbent MIPs were investigated for simultaneous extraction and clean-up of thiamethoxam and thiacloprid from light and dark honey samples. In this study, ultra-high-performance liquid chromatography-tandem mass spectrometry triple-quadrupole (UHPLC-MS/MS) (QQQ) was used to detect and quantify the pesticides. The kinetic model with adsorption kinetics of sorbent was investigated. The optimal adsorption conditions were 80 mg of polymer MIPs, a 30-min extraction time, and a pH of 7. The detection limit (LOD) and the quantification limit (LOQ) varied from 0.045 to 0.070 µg kg^-1 and from 0.07 to 0.10 µg kg^-1, respectively. The intra-day and inter-day precision (RSD, %) ranged from 1.3 to 2.0% and from 8.2 to 12.0%, respectively. The recovery of thiamethoxam and thiacloprid ranged from 96.8 to 106.5% and 95.3 to 104.4%, respectively, in light and dark honey samples.

Suitability of High-Resolution Mass Spectrometry for Routine Analysis of Small Molecules in Food, Feed and Water for Safety and Authenticity Purposes: A Review

During the last decade, food, feed and environmental analysis using high-resolution mass spectrometry became increasingly popular. Recent accessibility and technological improvements of this system make it a potential tool for routine laboratory work. However, this kind of instrument is still often considered a research tool. The wide range of potential contaminants and residues that must be monitored, including pesticides, veterinary drugs and natural toxins, is steadily increasing. Thanks to full-scan analysis and the theoretically unlimited number of compounds that can be screened in a single analysis, high-resolution mass spectrometry is particularly well-suited for food, feed and water analysis. This review aims, through a series of relevant selected studies and developed methods dedicated to the different classes of contaminants and residues, to demonstrate that high-resolution mass spectrometry can reach detection levels in compliance with current legislation and is a versatile and appropriate tool for routine testing.

Quality, composition and health-protective properties of citrus honey: A review

Citrus honey is one of the most important monofloral honeys produced and consumed worldwide. This honey has pleasant sensorial characteristics, which include light color and typical aroma and flavor. Besides that, several constituents such as minerals, phenolic and volatile compounds, amino acids, sugars, enzymes, vitamins, methylglyoxal and organic acids are found in citrus honey. Moreover, potential biological properties have been associated with citrus honey. All these factors make it highly desired by consumers, increasing its market value, which can stimulates the practice of fraud. Also, citrus honey is susceptible to contamination and to inadequate processing. All these factors can compromise the quality, safety and authenticity of citrus honey. In this sense, this review aims to update and to discuss, for the first time, the data available in the literature about the physicochemical and the sensorial characteristics, composition, health properties, contamination, authenticity and adulteration of citrus honey. With this background, we aim to provide data that can guide future researches related to this honey.

Recent development of antibiotic detection in food and environment: the combination of sensors and nanomaterials

In recent years, the abuse of antibiotics has led to the pollution of soil and water environment, not only poultry husbandry and food manufacturing will be influenced to different degree, but also the human body will produce antibody. The detection of antibiotic content in production and life is imperative. In this review, we provide comprehensive information about chemical sensors and biosensors for antibiotic detection. We classify the currently reported antibiotic detection technologies into chromatography, mass spectrometry, capillary electrophoresis, optical detection, and electrochemistry, introduce some representative examples for each technology, and conclude the advantages and limitations. In particular, the optical and electrochemical methods based on nanomaterials are discussed and evaluated in detail. In addition, the latest research in the detection of antibiotics by photosensitive materials is discussed. Finally, we summarize the pros and cons of various antibiotic detection methods and present a discussion and outlook on the expansion of cross-scientific areas. The synthesis and application of optoelectronic nanomaterials and aptamer screening are discussed and prospected, and the future trends and potential impact of biosensors in antibiotic detection are outlined.Graphical abstract.

Challenges and future directions in LC-MS-based multiclass method development for the quantification of food contaminants

Monitoring of food contaminants and residues has undergone a significant improvement in recent years and is now performed in an intensive manner. Achievements in the area of chromatography-mass spectrometry coupling techniques enabled the development of quantitative multi-target approaches covering several hundred analytes. Although the majority of methods are focusing on the analysis of one specific group of substances, such as pesticides, mycotoxins, or veterinary drugs, current trends are going towards the simultaneous determination of multiclass compounds from several families of contaminants and residues. This work provides an overview of relevant multiclass concepts based on LC-MS/MS and LC-HRMS instruments. Merits and shortcomings will be critically discussed based on current performance characteristics of the EU legislation system. In addition, the discussion of a recently developed multiclass approach covering >1000 substances is presented as a case study to illustrate the current developments in this area.

Untargeted multi-residue method for the simultaneous determination of 141 veterinary drugs and their metabolites in pork by high-performance liquid chromatography time-of-flight mass spectrometry

A rapid, simple and generic analytical method has been developed for the analysis of veterinary drugs in pork by a quadrupole time-of-flight mass spectrometry (Q-TOF MS). This method allows for the simultaneous identification, screening and quantitation of 141 veterinary drug residues and metabolites from eighteen different classes. After extraction with acetonitrile/water and clean-up with C₁₈ cartridges, the samples were analyzed by HPLC-Q-TOF MS. Validation of this method consisted of confirmation of identity, selectivity, linearity, limit of detection (LOD), lowest limit of quantification (LLOQ), matrix effect, recovery, precision and applicability of the method. Identification of the analytes was based on accurate mass measurements. The characteristic fragments were obtained by collisional experiments for a more reliable identification. The procedure was then applied to real pork samples. Sulfamethazine was detected in one sample and its metabolites were successfully found in one single run. This approach proved to be satisfactory for routine analysis.

A review of pretreatment and analysis of macrolides in food (Update Since 2010)

Macrolides are versatile broad-spectrum antibiotics whose activity stems from the presence of a macrolide ring. They are widely used in veterinary medicine to prevent and treat disease. However, because of their improper use and the absence of effective regulation, these compounds pose a threat to human health and the environment. Consequently, simple, quick, economical, and effective techniques are required to analyze macrolides in animal-derived foods, biological samples, and environmental samples. This paper presents a comprehensive overview of the pretreatment and analytical methods used for macrolides in various sample matrices, focusing on the developments since 2010. Pretreatment methods mainly include liquid-liquid extraction, solid-phase extraction, matrix solid-phase dispersion, and microextraction methods. Detection and quantification methods mainly include liquid chromatography (coupled to mass spectrometry or other detectors), electrochemical methods, capillary electrophoresis, and immunoassays. Furthermore, a comparison between the pros and cons of these methods and prospects for future developments are also discussed.

The use of UHPLC, IMS, and HRMS in multiresidue analytical methods: A critical review

Residue chemists who analyse pesticides in vegetables or veterinary drugs in animal-based food are currently facing a situation where there is a requirement to detect more and more compounds at lower and lower concentrations. Conventional tandem quadrupole instruments provide sufficient sensitivity, but speed and selectivity appear as future limitations. This will become an even larger issue when there is a need to not only detect active compounds but also their degradation products and metabolites. This will likely lead to a situation in which the conventional targeted approach must be expanded or augmented by a certain non-targeted strategy. High-resolution mass spectrometry provides such capabilities, but it frequently requires an additional degree of selectivity for the unequivocal confirmation of analytes present at trace levels in highly complex and variable food matrices. The hyphenation of ultrahigh performance liquid chromatography with ion mobility and high-resolution mass spectrometry provides analytical chemists with a new tool for performing such a demanding multiresidue analysis. The objective of this paper is to investigate the benefits of the added ion mobility dimension as well as to critically discuss the current limitations of this commercially available technology.

High-resolution mass spectrometry for bioanalytical applications: Is this the new gold standard?

Liquid chromatography coupled to quadrupole-based tandem mass spectrometry (QqQ) is termed the "gold standard" for bioanalytical applications because of its unpreceded selectivity, sensitivity, and the ruggedness of the technology. More recently, however, high-resolution mass spectrometry (HRMS) has become increasingly popular for bioanalytical applications. Nonetheless, this technique is still viewed, either as a screening technology or as a research tool. Although HRMS is actively discussed during scientific conferences, it is yet to be widely utilised in routine laboratory settings and there remains a reluctance to use HRMS for quantitative measurements in regulated environments. This paper does not aim to comprehensively describe the potential of the latest HRMS technology, but rather, it focuses on what results can be obtained and outlines the author's experiences over a period of many years of the routine application of various forms of HRMS instrumentation. Fifteen years ago, some nine different QqQ methods were used in the author's laboratory to analyse a variety of different veterinary drug resides. Today, many more analytes are quantified by seven HRMS methods and just three QqQ methods remain in use for the analysis of a small set of compounds yet to be upgraded to HRMS analysis. This continual upgrading and migration of analytical methods were accompanied by regularly participating in laboratory proficiency tests (PTs). The PT reports (covering a range of analytes and analytical methods) were used to compare the accuracy of HRMS- versus QqQ-based measurements. In the second part of this paper, the particular strengths and limitations of HRMS for both method development and routine measurements are critically discussed. This also includes some anecdotal experiences encountered when replacing QqQ assays with HRMS methods.

Analytical methods for mixed organic chemical residues and contaminants in food

Developing methods that can analyze multiple categories of organic chemical residues such as pesticides, veterinary drugs, mycotoxins, human drugs, and environmental contaminants in food with a single analytical procedure is a growing trend. These methods for mixed organic chemical residues and contaminants focus on the chemical properties of these analytes rather than how they are used and adulterate the food supply. This paper highlights recently published methods for mixed residue and contaminant methods in food including advances in technology (instrumental hardware, data processing programs, and sample cleanup) that allow for a larger number of compounds to be monitored simultaneously. The factors that determine the scope, or number and type of analytes in a given method, including needs for specific food commodities, complexity of the analytical procedure, and the intended purpose (qualitative vs quantitative analysis) will be examined. Although there are clear advantages to expanding the number of unwanted chemicals being monitored in the global food supply, challenges to developing and implementing mixed organic residue and contaminant methods will also be discussed. Going forward, it will be important to implement these methods to more thoroughly protect the food supply for a wide variety of targeted and non-targeted chemical residues and contaminants while also having the regulatory framework in place to effectively manage the results of these comprehensive analyses. Graphical abstract.

Stability of antibacterial and coccidiostat drugs on chicken meat burgers upon cooking and in vitro digestion

The impact of culinary practices - oven or microwave cooking combined with herbs and/or beer - on antibacterial and coccidiostat drugs stability and bioaccessibility in chicken meat was evaluated. Fourteen compounds from 6 classes (β-lactams, tetracyclines, sulfonamides, fluoroquinolones, macrolides, and coccidiostats) were monitored after cooking and in vitro digestion (INFOGEST protocol) at two fortification levels. Depending on their reduction, the presence of transformation products derived from cooking or digestion was investigated. In general, compounds were stable during cooking except amoxicillin, chlortetracycline and tylosin (reductions > 50%). Molecular rearrangement and dechlorination reactions are the most probable transformations derived from cooking. Adding herbs/beer does not benefit their reductions. During in vitro digestion, maximum bioaccessibilities of 60% were observed for all quantified compounds. As drugs and bile salts interact, increasing the absorption of lipophilic drugs, their bioaccessibility predictions must not be based only on the determination of their free form using LC-MS/MS.

Development and validation of a new method for the simultaneous determination of spinetoram J and L in honey from different botanical origins employing solid-phase extraction with a polymeric sorbent and liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

The objective of this study was to propose a novel method to determine residues of the bio-insecticide spinetoram, which is a mixture of two components (spinetoram J and L), in honey from multifloral, rosemary and heather botanical origins; liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was the technique employed. An efficient sample treatment (recoveries between 82% and 95%) involving a solid-phase extraction with a polymeric sorbent has been recommended, and no matrix effect was observed. Chromatographic analysis (4 min) was performed in reverse phase mode by using a fused-core column (Kinetex® EVO C₁₈) with acetonitrile and ammonium formate as the mobile phase components, which was applied in isocratic elution mode. Method was validated according to the current European legislation. Not only was it selective, but it also displayed a wide linear range, good precision (relative standard deviation values lower than 9%) and sensitivity (low limits of detection (spinetoram J, 0.1-0.3 μg/kg; spinetoram L, 0.1-0.2 μg/kg) and quantification (spinetoram J, 0.3-1.2 μg/kg; spinetoram L, 0.4-0.7 μg/kg)). Several honey samples were analyzed with this method and no spinetoram residues were found above the limits of detection.

Determination of pesticide levels in wastewater from an agro-food industry: Target, suspect and transformation product analysis

Agriculture is considered as the main source of water contamination by pesticides. However, food packaging or processing industries are also recognised as relevant point sources of contamination by these compounds, not yet investigated in depth. The objective of this work has been to improve current knowledge about the presence and concentration of pesticides in the effluent of a food processing industry, as well as to investigate their main transformation products (TPs). An analytical strategy combining target and suspect analysis has been applied to provide an evaluation of the effluents. The methodology involves solid-phase extraction (SPE) of wastewater samples followed by (i) liquid chromatography quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS) for quantitative target analysis and (ii) liquid chromatography coupled to quadrupole-time-of-flight high resolution mass spectrometry (LC-QTOF-HRMS) to identify non-target pesticides and possible TPs. The results revealed the presence of 17 of the target pesticides analysed and 3 additional ones as a result of the suspect screening performed by HRMS. The TPs were investigated for the pesticides found at the highest concentrations: imazalil (7038-19802 ng/L), pyrimethanil (744-9591 ng/L) and thiabendazole (341-926 ng/L). Up to 14 TPs could be tentatively identified, demonstrating the relevance of this type of studies. These data provide a better understanding of the occurrence of pesticides and their TPs in agro-food industrial effluents.

Development of a screening analytical method for the determination of non-dioxin-like polychlorinated biphenyls in chicken eggs by gaschromatography and electron capture detection

A sensitive and reproducible screening analytical method is here proposed for the determination of six non dioxin-like polychlorinated biphenyls (NDL-PCBs, congener 28, 52, 101, 138, 153, 180) in chicken eggs based on accelerated solvent extraction (ASE) procedure for the fat extraction and determination, a solid phase extraction (SPE) sample clean-up process, and a gas chromatography - electron capture detection (GC-ECD) analysis. The optimized chromatographic separation, in less than 25 min, returned good responses for the six NDL-PCBs in the range of 2.5-60.0 µg L^-1, with correlation coefficients always higher than 0.9995. Instrumental limits of detection were between 0.08-0.35 µg L^-1, corresponding to 0.05 and 0.23 ng g^-1 fat in the matrix, while method detection limits, calculated on spiked egg samples, ranged from 1.6 to 3.5 ng g^-1 fat. The method has been extensively validated in terms of selectivity, sensitivity, recovery, precision, ruggedness and measurement uncertainty, following the European Directives.

Simultaneous determination of pesticides and mycotoxins in wine by direct injection and liquid chromatography-tandem mass spectrometry analysis

A simple and rapid method for simultaneous determination of pesticides and mycotoxins in red wine is presented. Sample preparation approach, called direct injection, consists of a sequence of only three steps: centrifugation, dilution and filtration. The analysis of extracts were performed by UPLC-MS/MS for determination of pesticides and mycotoxins. The method was assessed for linearity, limits of detection and quantification, matrix effects, selectivity, accuracy and precision. For recovery experiments, mycotoxins were divided in two groups according to their sensitivity in the UPLC-MS/MS system. More than 80% of the mycotoxins were reliably quantified at the lowest spike level studied (1 μg kg^-1 for group 1 and 50 μg kg^-1 for group 2). From the 185 evaluated pesticides, 144 showed acceptable results at 10 μg kg^-1, the lowest spiked level. Matrix effects were, in most of the cases, negative, and that was observed for both pesticides and mycotoxins.

Functionalization of amino terminated carbon nanotubes with isocyanates for magnetic solid phase extraction of sulfonamides from milk and their subsequent determination by liquid chromatography-high resolution mass spectrometry

A simple modification method was developed for the functionalization of amino terminated carbon nanotubes (CNT-NH₂) by using isocyanates as modifiers via the nucleophilic addition reaction. Two types of functionalized magnetic carbon nanotubes (MCNT) were prepared through deposition of magnetic nanoparticles on CNT-NH₂ and modification with different isocyanates. p-Tolyl-functionalized MCNT (Tol-MCNT) with better adsorption performance were selected as adsorbent for magnetic solid phase extraction (MSPE), which could extract sulfonamides (SAs) from various milk samples with a enrichment factor of about 30 after optimization. By combining the MSPE with liquid chromatography-high resolution mass spectrometry (LC-HRMS), a new method was developed. Both skimmed and whole milk samples of three brands were analyzed with this method, and 4 SAs including sulfadiazine, sulfisomidine, sulfamethazine and sulfameter were detected with the concentration from unquantifiable to 72 ng/L, which were all well below the maximum residue limits in milk according to the regulations of China and EU.

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.

An Electrochemical Sensor for Diphenylamine Detection Based on Reduced Graphene Oxide/Fe₃O₄-Molecularly Imprinted Polymer with 1,4-Butanediyl-3,3'-bis-l-vinylimidazolium Dihexafluorophosphate Ionic Liquid as Cross-Linker

In this paper, we report a new composite of reduced graphene oxide/Fe₃O₄-ionic liquid based molecularly imprinted polymer (RGO/Fe₃O₄-IL-MIP) fabricated for diphenylamine (DPA) detection. RGO/Fe₃O₄-IL-MIP was prepared with RGO/Fe₃O₄ as supporter, ionic liquid 1-vinyl-3-butylimidazolium hexafluorophosphate ([VC₄mim][PF₆]) as functional monomer, ionic liquid 1,4-butanediyl-3,3'-bis-l-vinylimidazolium dihexafluorophosphate ([V₂C₄(mim)₂][(PF₆)₂]) as cross-linker, and diphenylamine (DPA) as template molecule. Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy, and vibrating sample magnetometer were employed to characterize the RGO/Fe₃O₄-IL-MIP composite. RGO/Fe₃O₄-IL-MIP was then drop-cast onto a glassy carbon electrode to construct an electrochemical sensor for DPA. The differential pulse voltammetry (DPV) peak current response for 20 μM DPA of RGO/Fe₃O₄-IL-MIP modified glassy carbon electrode (GCE) was 3.24 and 1.68 times that of RGO/Fe₃O₄-IL-NIP and RGO/Fe₃O₄-EGDMA-MIP modified GCEs, respectively, indicating the advantage of RGO/Fe₃O₄-IL-MIP based on ionic liquid (IL) as a cross-linker. The RGO/Fe₃O₄-IL-MIP sensor demonstrated good recognition for DPA. Under the optimized conditions, the RGO/Fe₃O₄-IL-MIP sensor exhibited a DPA detection limit of 0.05 μM (S/N = 3) with a linear range of 0.1⁻30 μM. Moreover, the new RGO/Fe₃O₄-IL-MIP based sensor detected DPA in real samples with satisfactory results.

Distribution of POPs, pesticides and antibiotic residues in organic honeys from different production areas

Demand for honey is increasing, especially if it is organic and if its nutritional properties are linked to untreated environments in order to guarantee quality for health. Sources of contamination of honey can be divided into environmental and apicultural. Therefore, the distribution of persistent organic pollutants, pesticides and antibiotic residues from geographical areas with different contamination sources (high anthropic impact, intensive farming, husbandry and low anthropic impact) was investigated in order to confirm the potential transfer of xenobiotics into the supply chain and to give beekeepers tools for the selection of areas dedicated to organic production. The presence of polychlorinated biphenyls, polybrominated diphenyl ether and polycyclic aromatic hydrocarbons was confirmed, not only in proximity to highly urbanised centres, where the concentrations were higher, but in all environment contexts, confirming their ubiquity. No antibiotics or neonicotinoids were detected in 95 organic honeys, demonstrating the absence of apicultural treatments and consequently the good quality of honey of different areas. These results are important due to the undefined regulatory European situation on honey antibiotic limits.

Screening of veterinary drug residues in food by LC-MS/MS. Background and challenges

Regulatory agencies and government authorities have established maximum residue limits (MRL) in various food matrices of animal origin for supporting governments and food operators in the monitoring of veterinary drug residues in the food chain, and ultimately in the consumer's plate. Today, about 200 veterinary drug residues from several families, mainly with antibiotic, antiparasitic or antiinflammatory activities, are regulated in a variety of food matrices such as milk, meat or egg. This article provides a review of the regulatory framework in milk and muscle including data from Codex Alimentarius, Europe, the U.S.A., Canada and China for about 220 veterinary drugs. The article also provides a comprehensive overview of the challenge for food control, and emphasizes the pivotal role of liquid chromatography-mass spectrometry (LC-MS), either in tandem with quadrupoles (LC-MS/MS) or high resolution MS (LC-HRMS), for ensuring an adequate consumer protection combined with an affordable cost. The capability of a streamlined LC-MS/MS platform for screening 152 veterinary drug residues in a broad range of raw materials and finished products is highlighted in a production line perspective. The rationale for a suite of four methods intended to achieve appropriate performance in terms of scope and sensitivity is presented. Overall, the platform encompasses one stream for the determination of 105 compounds in a run (based on acidic QuEChERS-like), plus two streams for 23 β-lactams (alkaline QuEChERS-like) and 10 tetracyclines (low-temperature partitioning), respectively, and a dedicated stream for 14 aminoglycosides (molecularly-imprinted polymer).

MS-Based Analytical Techniques: Advances in Spray-Based Methods and EI-LC-MS Applications

Mass spectrometry is the most powerful technique for the detection and identification of organic compounds. It can provide molecular weight information and a wealth of structural details that give a unique fingerprint for each analyte. Due to these characteristics, mass spectrometry-based analytical methods are showing an increasing interest in the scientific community, especially in food safety, environmental, and forensic investigation areas where the simultaneous detection of targeted and nontargeted compounds represents a key factor. In addition, safety risks can be identified at the early stage through online and real-time analytical methodologies. In this context, several efforts have been made to achieve analytical instrumentation able to perform real-time analysis in the native environment of samples and to generate highly informative spectra. This review article provides a survey of some instrumental innovations and their applications with particular attention to spray-based MS methods and food analysis issues. The survey will attempt to cover the state of the art from 2012 up to 2017.

Degradation studies of quizalofop-p and related compounds in soils using liquid chromatography coupled to low and high resolution mass analyzers

A comprehensive degradation study of quizalofop-p, quizalofop-p-ethyl, quizalofop-p-tefuryl and propaquizafop in soil samples have been firstly performed using ultra high performance liquid chromatography coupled to Orbitrap mass spectrometry (UHPLC-Orbitrap-MS). Thus, metabolites or degradation products, such as CHHQ (dihydroxychloroquinoxalin), CHQ (6-chloroquinoxalin-2-ol), PPA ((R)-2-(4-hydroxyphenoxy)propionic acid) and 2,3-dihydroxyquinoxaline were also monitored. An extraction procedure based on QuEChERS procedure was used. Acidified water (0.1M hydrochloric acid) and acidified acetonitrile (1% acetic acid, (v/v)) were used as extraction solvents, and magnesium sulfate and sodium chloride were used as salts. Dispersive solid phase extraction with C₁₈ as sorbent, was needed as a clean-up step. Several commercial products (Panarex®, Master-D® and Dixon®) were used to evaluate the degradation of the target compounds into their metabolites. The concentration of the main active substances (quizalofop-p-tefuryl, quizalofop-p-ethyl and propaquizafop) decreased during the degradation studies, whereas the concentration of quizalofop-p increased. Dissipation rates of half-live of quizalofop-p were also evaluated, and it was observed that this compound is easily degraded, obtaining values lower than 1day. Taking into account that quizalofop-p is the R enantiomer of quizalofop, a chiral separation was performed by liquid chromatography coupled to tandem mass spectrometry, concluding that in samples containing quizalofop-p-tefuryl, there was a 15% contribution from the S enantiomer and a 85% contribution from the R enantiomer. Metabolites such as PPA, CHHQ and CHQ were detected in soil samples after 15days of application commercial product at concentrations between the limits of detection (LOD) and the limits of quantification (LOQ). CHQ and CHHQ were detected at concentrations higher than the LOQ in samples after 50 and 80days of application, with their concentration increasing during this time up to 500%.

Multiresidue Method for the Rapid Determination of Pesticide Residues in Tea Using Ultra Performance Liquid Chromatography Orbitrap High Resolution Mass Spectrometry and In-Syringe Dispersive Solid Phase Extraction

A method based on in-syringe dispersive solid phase extraction (IS-D-SPE) and ultra performance liquid chromatography Orbitrap high resolution mass spectrometry for the multiresidue analysis of 117 pesticides in tea was developed. Full scan mode was acquired over an m/z range of 100-800 with Orbitrap resolution at 70000, followed by full scan/dd-MS² mode for confirmation. The identification criteria of retention time and mass accuracy tolerance was ±0.20 min and ±5.0 ppm, respectively. MS/MS fragment ions obtained dd-MS² were necessary to identify the pesticides with the same molecular mass weight. The IS-D-SPE technique involved a mixture of 200 mg PSA, 100 mg C18, and 15 mg multiwalled carbon nanotubes for the cleanup of tea matrix. Good linearity (R² > 0.99) for 117 pesticides was obtained. Satisfactory recoveries in the range of 70-120% were obtained for 105 pesticides, while intraday and interday precisions were below 20%. Limits of quantification were generally 10 μg kg^-1. Finally, this method was employed to analyze 117 pesticides in 70 tea samples.

Quantification of 16 β-lactams in chicken muscle by QuEChERS extraction and UPLC-Q-Orbitrap-MS with parallel reaction monitoring

A method is described for the analysis of 16 β-lactams in chicken muscle by UPLC-quadrupole(Q)-Orbitrap-MS with parallel reaction monitoring (PRM). QuEChERS approach includes clean-up step by sorbent of primary-secondary amine (PSA) and C18 was adopted for sample preparation. Q-Orbitrap with PRM showed high sensitivity with limits of detection (LODs) ranged from 0.01μgkg^-1 to 0.35μgkg^-1. The method was further validated by intra- and inter-day test with spiking levels less than MRLs (maximum residue limits, the European Union). Recovery (83-112%) and precision values (RSDs <15%) for all studied analytes were obtained. The result indicates that UPLC-Q-Orbitrap coupled with QuEChERS preparation can serve as a routine quantification method for β-lactam residues in chicken muscles.

The exposure of honey bees (Apis mellifera; Hymenoptera: Apidae) to pesticides: Room for improvement in research

Losses of honey bees have been repeatedly reported from many places worldwide. The widespread use of synthetic pesticides has led to concerns regarding their environmental fate and their effects on pollinators. Based on a standardised review, we report the use of a wide variety of honey bee matrices and sampling methods in the scientific papers studying pesticide exposure. Matrices such as beeswax and beebread were very little analysed despite their capacities for long-term pesticide storage. Moreover, bioavailability and transfer between in-hive matrices were poorly understood and explored. Many pesticides were studied but interactions between molecules or with other stressors were lacking. Sampling methods, targeted matrices and units of measure should have been, to some extent, standardised between publications to ease comparison and cross checking. Data on honey bee exposure to pesticides would have also benefit from the use of commercial formulations in experiments instead of active ingredients, with a special assessment of co-formulants (quantitative exposure and effects). Finally, the air matrix within the colony must be explored in order to complete current knowledge on honey bee pesticide exposure.