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Background Pesticide quantitation in foods relies on the availability of matrix reference materials, which, however, are scarce because of the general instability of pesticides. In particular, no avocado reference material has been developed. Objective This research aimed to develop a reference material to support the determination of pesticide residues in avocado. Method Avocado was spiked with 11 selected pesticides at levels of 0.01–0.35 mg/kg. The production process included the assessment of between-unit heterogeneity, stability during dispatch, and best storage conditions according to ISO 17034. Reference values were estimated through an interlaboratory comparison study involving laboratories of demonstrated competence and adhering to ISO/IEC 17025. The corresponding expanded uncertainties were calculated as 4–19% in compliance with the Guide to the Expression of Uncertainty in Measurement. Results The reference material was sufficiently homogeneous and stable at 4°C during the entire study period (365 days) for most of the pesticides, and at 40°C during 10 days, but it was unstable at 50 and 60°C during 10 days. Four pesticides showed downward trends; however, this behavior was considered in the uncertainty budget. As this material complied with all requirements of proficiency testing, it was used in an interlaboratory proficiency test designed to investigate analytical performance and assist laboratories in improving the quality of measurement results. Conclusions The presented material can be used for the development of novel analytical methods or in-house reference materials and adds to the scarce supply of reference materials for the determination of pesticides in vegetable matrixes with high oil contents and intermediate water contents. Highlights A novel reference material has been developed for the reliable and accurate quantitation of multiple pesticides in avocado, allowing researchers to avoid the preparation of in-house reference materials for this purpose.

There is an increasing concern about the use of synthetic acaricides to fight the ectoparasitic mite Varroa destructor. Natural products such as formic acid (FA) and oxalic acid (OA) have emerged as a possible alternative control strategy. However, given the difficulty of analysing these highly polar compounds and the lack of robust and reliable methods, there are very few studies of the concentration and distribution of these natural acaricides in the beehive compartments. We present a reliable and simple analytical methodology, based on sample extraction with modified quick polar pesticide (QuPPe) methods followed by ion chromatography coupled to a quadrupole Orbitrap mass analyser for the analysis of FA and OA in honeybees, honey, beeswax, and beebread. The developed methods have been used in a field study for the evaluation of the presence and distribution of FA and OA in the beehive products, as well as in adult bees and bee brood samples, before, during, and up to 3 months after the application of the treatments by the beekeeper. Beebread and honey samples presented the highest concentration levels of OA and FA, respectively, mainly due to their natural presence. As expected, the organic acids showed low persistence in wax after the treatments. The natural acaricides were found in adult and developing bees at concentration levels below the reported LD50 in all the cases; however, residue levels of OA in larvae during the treatment application were very close to the reported LD50. Graphical abstract

Graphical abstract Abundant studies have been published evaluating different parameters of reverse-phase liquid chromatography (LC) and supercritical fluid chromatography (SFC), both coupled to electrospray (ESI)/mass spectrometry (MS) for pesticide residue analysis. However, there is a lack of a comprehensive comparative study that facilitates deep knowledge about the benefits of using each technique. In the present study, the same mass spectrometer was used coupled to both liquid and supercritical fluid chromatographies with a multiresidue method of 215 compounds, for the analysis of pesticide residues in food samples. Through the injection of the spiked extracts, separate experiments were conducted. A study of the optimum ion source temperature using the different chromatography modes was performed. The results were evaluated in terms of sensitivity with tomato, leek, onion, and orange as representative fruit and vegetable matrices. The compounds which reported the highest area values in each chromatography were evaluated through their substance groups and polarity values. The impact of matrix effects obtained in tomato matrix was similar for both cases; however, SFC clearly showed better results in analyzing matrices with a higher number of natural co-extracted compounds. This can be explained by the combination of two effects: (i) chromatography separation and (ii) ion source efficiency. The chromatographic elution presented different profiles of matrix components, which had diverse impact on the coelution with the analytes, being more beneficial when SFC was used in the matrices studied. The data showed that the best results obtained in SFC are also related to a higher ionization efficiency even when the ESI emitter tip was not optimized for SFC flow. In the present study a comprehensive evaluation of the benefits and drawbacks of these chromatography modes for routine pesticide residue analysis related to target compounds/commodities is provided. Supplementary Information The online version contains supplementary material available at 10.1007/s00216-021-03565-4.

In this study, we aimed to validate and apply a quick and easy extraction method for the simultaneous determination of 27 pesticide residues at trace levels in agricultural samples (soil, fruit, and leaf) to monitor the presence of these contaminants released from reclaimed water. The procedure was based on a salting-out extraction method with acidified acetonitrile, followed by a dispersive solid-phase extraction (d-SPE) clean-up step applying the C18 sorbent. Ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry (LC-MS/MS) was used for identification and quantification of the target analytes. This methodology provided recovery values higher than 70%, for all pesticides and matrices evaluated in the study, except for propamocarb in soil samples (35%). Repeatability and reproducibility results, calculated as relative standard deviations (RSD, %), ranged between 1% and 18% in both cases. No remarkable matrix effects were observed for vegetable samples, except for thiamethoxam in red cabbage, and hexythiazox in carrot and leaves (between 30 and 40%). Soil samples showed a moderate matrix effect (between 21 and 35%) for more than 80% of the compounds. Monitoring pesticide residues found in agricultural samples irrigated with contaminated reclaimed water under controlled conditions revealed the efficacy of the proposed method. Three common vegetables were grown to evaluate the different migration and distribution rates in crops and soil. Pesticide accumulation in the different parts of the crop (soil, fruit, and leaves) and the potential human exposure to pesticides through daily intake were also discussed.

Anthraquinone has been linked to potential adverse effects on human health and the environment. The most commonly employed methods for the analysis of coffee and tea cause the extraction of matrix interferents such as the methylxanthines caffeine and theobromine, which hinder the analysis of anthraquinone. A new manual extraction method – using ethyl acetate as the extraction solvent with a dispersive solid-phase extraction clean-up step based on primary–secondary amines – has been developed. The new developed method allows for the quantitation of anthraquinone at 5 μg kg−1 concentration levels, four times lower than the current maximum residue limit for coffee and tea in the European Union (20 μg kg−1). Alongside, a new automated extraction method has also been developed. Finally, a pilot monitoring programme of 90 coffee and tea samples from several countries within the European Union has been performed, in which anthraquinone has been detected in a concentration range of 5.1–18.8 μg kg−1 in 32% of the monitored samples, below the current 20 μg kg−1 maximum residue limit, and in 48% of the monitored tea samples, revealing the need for including anthraquinone in a more extensive monitoring programme of tea.

11 Pág. Centro de Investigación en Sanidad Animal (CISA), This nationwide monitoring aimed to investigate the prevalence of residues of plant protection products (PPPs) and veterinary medicine products (VMPs) based on random selection of apiaries of Apis mellifera. For a three-year period (2012, 2013 and 2016), this study targeted 306 PPPs, VMPs and other active substances in 442 samples of bee bread honeycomb (BBHC) and 89 samples of honeybees collected from up to 177 apiaries. The results indicate that honeybees were most often exposed to residues of coumaphos, tau-fluvalinate, chlorfenvinphos, and acrinathrin, with a prevalence from a maximum of 98.8% to 49.4% in BBHC samples. Residues of coumaphos, tau-fluvalinate, amitraz (DMF + DMPF), carbendazim and orthophenylphenol were also frequently detected, from a maximum of 55.1% to 13.5% of the honeybee samples. Neonicotinoid residues, namely clothianidin and thiamethoxam, whose outdoor uses in crops are completely banned in EU, were not detected. Imidacloprid was found in 3.4% to 13.3% of samples during 2013 and 2016, respectively. Imidacloprid exceeded its acute toxicity (LD50) value for honey bees in two samples of BBHC. Fipronil was detected in 0.5% of the samples during 2013. The diversity of active substances found (% of different residues analyzed) ranged from 33.9% to 37.2% in BBHC from 2012, 2013 to 2016, and was of 26.5% in honeybees in 2016. In at least 54% of the samples, the total residue load was in the range of 200 to 1500 μg·kg-1. Up to 50% of BBHC samples were positive for one or two residues. No toxic residues for honeybees were detected in up to 88.8% of bee samples. This systematic surveillance of active substances assisted the evaluation of which target pesticides to look for and provided support to the competent authorities in the bee health decision-making., The authors acknowledge the voluntary participation of all the beekeepers involved in the program, the work carried out by the official veterinary services of all the participating Autonomous Communities and their bee inspectors in taking samples. Special mention to the work team of the Ministry of Agriculture, Fisheries and Food in the coordination of the surveillance program integrated by the General Subdirectorate of Animal Health and Hygiene and Traceability, the Department of Bee and Fish Diseases of the Central Veterinary Laboratory of Algete and the Agroalimentary Arbitration Laboratory of Aravaca.

Thymol has been considered as an organic varroacide with less toxicity than synthetic chemicals such as amitraz, coumaphos or tau-fluvalinate. The present study evaluates the presence, persistence and distribution of thymol during a five-month sampling period; before, during and after the application of thymol treatment in field conditions. Moreover, its impact on the development of bee brood was also studied at different development stages which consist of larvae, prepupae, pupae and adult honeybee. Samples of beebread (processed pollen), honey, beeswax, adult bees, pupae, prepupae and larvae were analysed by gas chromatography coupled to time of flight mass spectrometry for an accurate identification. Adult bees were the samples with the highest concentration level of thymol during treatment application (Thymovar® strips, 30 gr of thymol per hive) by the beekeeper, however they showed 69% of thymol dissipation three months after treatment. Regarding the bee brood, concentrations of thymol decreased significantly (89-97% of disappearance) in a period of three months, though about 42 µg/kg of thymol persisted in larvae. Thymol was found to accumulate in honey and beeswax at a level of 882 μg/kg and 1305 μg/kg respectively, in the studied period. As the main issue of thymol residues in honey is related to the modification of organoleptic properties, more than toxicology, the levels found in this study indicate that the taste of honey may be affected during and up to three months after the treatment application. In addition, we did not find adverse effects on the evolution of the colonies due to the applied treatment.

Two high-resolution instruments (a QToF and a QOrbitrap) were used to evaluate a segmented non-target MS2 (SWATH/vDIA) acquisition for pesticide residue analysis. Three matrices (tomato, orange, and leek) and 163 pesticides were used for this study. Samples were analysed by use of 1, 5, 8, and 20 mass windows and the last one was used only in the QToF. The objectives of the evaluation were: the number of detected fragment ions, mass accuracy, ion ratio, and sensitivity. Obtained results showed a positive influence of the mass windows on the detection of the fragment ions, ion ratio stability and mass accuracy with no effect on the sensitivity of the analysis. The experiments revealed the importance of the size of the mass windows selected. Therefore, the use of variable mass windows optimizing the size is necessary in case of limitations of the scan speed. Nevertheless, the contemporary instrumentation still cannot achieve a high number of very narrow mass windows (

This review is focused on the application of Orbitrap™ mass spectrometry for pesticide residue analysis. The importance of mass accuracy and resolution is explained. Also, the most typical acquisition modes available in QOrbitrap™ are discussed.

Most widely developed approaches for pesticide residues analysis in spices and herbs present serious limitations; this is because of the high number of interferences that they typically contain, which makes it difficult to identify/quantify compounds in a considerable percentage of cases. Different strategies are applied to overcome these difficulties including extensive clean-up steps, dilution of the extracts, more selective detection techniques and other effective methods. However, there is a strong matrix effect present with the most complex matrices. Recent advances with new clean-up sorbents and the greater sensitivity and selectivity provided by modern mass spectrometers facilitates the determination of pesticide residues in these complex matrices at the desired limits of quantification. This review summarizes the main sample extraction and clean-up procedures for pesticide residues in spices and herbs published between 2008 and 2018, evaluating both their strengths and limitations. In addition, the high-end mass spectrometry detection methods are critically discussed.

This study describes a comprehensive comparison between supercritical fluid chromatography (SFC) and gas chromatography (GC) coupled to mass spectrometry for the analysis of pyrethroids in vegetable matrices. The ionization process used was electrospray ionization (ESI) in SFC and electron ionization in GC. In general, liquid chromatography coupled to mass spectrometry with ESI sources provides poor results for pyrethroid detection, as described in previous literature. A total of 14 pyrethroids were selected, together with 6 representative matrices. The differences in chromatographic separation and ionization process were assessed. Similar results were obtained in terms of sensitivity (limits of quantification close to 2 μg/kg, injecting the same amount of sample), matrix effect, and linearity. A total of 17 real samples were analyzed by both systems, obtaining similar results. These data suggest that SFC offers a suitable alternative to GC in the analysis of pyrethroids and allows for their inclusion in a wider multiresidue method.

Due to their extensive use in both agricultural and non-agricultural applications, pesticides are a major source of environmental contamination. Honey bee colonies are proven sentinels of these and other contaminants, as they come into contact with them during their foraging activities. However, active sampling strategies involve a negative impact on these organisms and, in most cases, the need of analyzing multiple heterogeneous matrices. Conversely, the APIStrip-based passive sampling is innocuous for the bees and allows for long-term monitorings using the same colony. The versatility of the sorbent Tenax, included in the APIStrip composition, ensures that comprehensive information regarding the contaminants inside the beehive will be obtained in one single matrix. In the present study, 180 APIStrips were placed in nine apiaries distributed in Denmark throughout a six-month sampling period (10 subsequent samplings, April to September 2020). Seventy-five pesticide residues were detected (out of a 428-pesticide scope), boscalid and azoxystrobin being the most frequently detected compounds. There were significant variations in the findings of the sampling sites in terms of number of detections, pesticide diversity and average concentration. A relative indicator of the potential risk of pesticide exposure for the honey bees was calculated for each sampling site. The evolution of pesticide detections over the sampling periods, as well as the individual tendencies of selected pesticides, is herein described. The findings of this large-scale monitoring were compared to the ones obtained in a previous Danish, APIStrip-based pilot monitoring program in 2019. Samples of honey and wax were also analyzed and compared to the APIStrip findings.

The active substances coumaphos, tau-fluvalinate and amitraz are among the most commonly employed synthetic miticides to control varroa infestations in apiculture. These compounds can persist inside the beehive matrices and can be detected long time after their application. The present study describes the application of a new passive sampling methodology to assess the dissipation of these miticides as well as the cross-contamination in neighboring beehives. The APIStrips are a recently developed sampling device based on the sorbent Tenax, which shows a remarkable versatility for the sorption of molecules onto its surface. This avoids the need of actively sampling apicultural matrices such as living bees, wax or reserves (honey and pollen), therefore allowing to obtain representative information of the contamination in the beehive environment in one single matrix. The results show that the amitraz-based treatments have the fastest dissipation rate (half-life of 11-14 days), whereas tau-fluvalinate and coumaphos remain inside the beehive environment for longer time periods, with a half-life up to 39 days. In the present study, tau-fluvalinate originated an intense cross-contamination, as opposed to coumaphos and amitraz. This study also demonstrates the contribution of drifting forager bees in the pesticide cross-contamination phenomena. Moreover, the sampling of adult living bees has been compared to the APIStrip-based sampling, and the experimental results show that the latter is more effective and consistent than traditional active sampling strategies. The active substances included in this study do not migrate to the honey from the treated colonies in significant amounts.

In this study, we aimed to develop and validate a quick, easy, and robust extraction method for the simultaneous determination of 30 organic contaminants of emerging concern (CECs) including some transformation products in soil samples. Three different extraction methods based on an ultrasonic cylindrical probe (UAE), a pressurized liquid extraction (PLE), and a QuEChERS method were compared. Ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry (LC-MS/MS) was used for identification and quantification of the target analytes. A modified QuEChERS method showed the best results in terms of extractability and accuracy. The extraction procedure developed provided adequate extraction performances (70% of the target analytes were recovered within a 70-99% range), with good repeatability and reproducibility (variations below 20%) and great sensitivity (LOQ0.1 ng/g in most cases). No matrix effects were observed for 70% of the compounds. Finally, the analytical methodology was applied in a pilot study where agricultural soil was irrigated with reclaimed water spiked with the contaminants under study. Of the 25 CECs added in irrigation water, a total of 13 pesticides and 5 pharmaceutical products were detected at concentration ranges from 0.1 to 1.2 ng/g (d.w) and from 0.1 to 2.0 ng/g (d.w), respectively.

The use of high-resolution mass spectrometry (HRMS) for the simultaneous target and non-target analysis of pesticide residues in food control is a subject that has been studied over the last decade. However, proving its efficacy compared to the more established triple quadrupole mass spectrometers (QQQ-MS2) is challenging. Various HRMS platforms have been evaluated, seemingly showing this approach not to be as effective as QQQ-MS2 for quantitative analysis, especially in routine food testing laboratories. The two main reasons are (i) the lower sensitivity especially in the case of the fragment ions produced and (ii) the lack of familiarity and an understanding of the most appropriate combination of HRMS acquisition modes to use. In fact, the number of different acquisition modes can appear as a puzzle to inexperienced users. This work was therefore focused on obtaining experimental data to gain a better understanding of the extended acquisition capabilities of a new Q-Orbitrap platform. Experimental data were obtained for 244 pesticides and their degradation products in commodities of varying matrix complexity (tomato, onion, avocado, and orange) using various combinations of acquisition modes. The best results for targeted analysis were obtained with a combination of full scan (FS), all-ions fragmentation (AIF) and target MS2 (tMS2) modes, and for non-target analysis using full scan (FS) and data-dependent MS2 (ddMS2) modes. All these acquisition modes (FS, AIF, tMS2, and ddMS2) could be applied simultaneously with cycle times ≤ 1 s. The tMS2 especially, proved to be a very powerful approach to increase sensitivity for MS2 fragments and identification rates. Overall, the results for the various pesticide-commodity combinations were fully satisfactory in terms of limit of quantitation (LOQ) repeatability and identification when considered against the SANTE EU Guideline criteria. In addition, the screening capabilities were evaluated for a non-target survey with the use of spectral libraries, the presence of non-target compounds was detected, thus proving the efficacy of the proposed approach. Another issue often overlooked is the optimization of use of spectral libraries, but in our experiments the compounds present in these libraries were not blindly sought in the screening analyses. To minimize the potential for false positives detects in our study, the extractability of the compounds present in the libraries, was also taken into account. The extractability of compounds using a QuEChERS acetonitrile procedure was estimated based on the physicochemical properties of target compounds. By removing compounds that will not be extracted, reduces the occurrences of false detects, reducing the time required for data processing and thus improving the efficiency of the overall screening workflow.

Nontarget data acquisition for target analysis (nDATA) workflows using liquid chromatography-high-resolution accurate mass (LC-HRAM) spectrometry, spectral screening software, and a compound database have generated interest because of their potential for screening of pesticides in foods. However, these procedures and particularly the instrument processing software need to be thoroughly evaluated before implementation in routine analysis. In this work, 25 laboratories participated in a collaborative study to evaluate an nDATA workflow on high moisture produce (apple, banana, broccoli, carrot, grape, lettuce, orange, potato, strawberry, and tomato). Samples were extracted in each laboratory by quick, easy, cheap, effective, rugged, and safe (QuEChERS), and data were acquired by ultrahigh-performance liquid chromatography (UHPLC) coupled to a high-resolution quadrupole Orbitrap (QOrbitrap) or quadrupole time-of-flight (QTOF) mass spectrometer operating in full-scan mass spectrometry (MS) data-independent tandem mass spectrometry (LC-FS MS/DIA MS/MS) acquisition mode. The nDATA workflow was evaluated using a restricted compound database with 51 pesticides and vendor processing software. Pesticide identifications were determined by retention time (tR, ±0.5 min relative to the reference retention times used in the compound database) and mass errors (δM) of the precursor (RTP, δM ≤ ±5 ppm) and product ions (RTPI, δM ≤ ±10 ppm). The elution profiles of all 51 pesticides were within ±0.5 min among 24 of the participating laboratories. Successful screening was determined by false positive and false negative rates of

9 Pág., Despite the restriction of the use of neonicotinoids in the EU, including thiamethoxam and clothianidin, the debate over their risk on honey bees has not been fully settled. This study presents results of a three-year study working with 180 honey bee colonies in ten replicates. Colonies were sorted into three treatments (60 colonies per treatment) exposed to sunflower blooms grown from seeds treated with thiamethoxam, clothianidin and a non-treated control. Each colony was assessed at six moments: one before to exposition to sunflower, two during the exposition (short-time risk), two after exposition (medium-time risk) and one after wintering (long-time risk). The health and development of the colonies were assessed by monitoring adult bee population, brood development, status of the queen, food reserves and survival. No significant difference among treatments when raw data was considered. However, when evolution from initial status of the colony was evaluated, a significant difference was observed from the first week of exposure to sunflower blooms. In this period, the number of adult bees and the amount of brood were slightly lower in the bee hives exposed to neonicotinoids, although such differences disappeared in subsequent evaluations. The concentration of residues in samples of beebread and adult bees was at the level of ng·g-1. Magnitude of the effect of the treatment factor on the variability of colony health and development related parameters was low. The most important factor was the hive, followed by the replicate and year, and to a lesser extent the initial strength of the colonies., This study has been carried out in line with the framework of the project RTA2013-00042-C10.

Highly polar pesticides are frequently used in agriculture. However, their physicochemical properties make very difficult the analysis of these compounds following common procedures. Polar pesticides show poor retention and peak shapes in the common stationary phases used for multiresidue methods of pesticides. For this reason, multiple columns with different stationary phases have been developed to perform the analysis of these particular compounds. The column evaluated in this method uses a new hybrid stationary phase with a mixed-mode between hydrophilic interaction liquid chromatography (HILIC) and ion exchange interactions. The retention modes are dependant on mobile phase conditions and can be easily switched. The aim of this study can be summarized in the next bullet points: • Performance evaluation of 10 anionic compounds in different column sizes of the hybrid stationary phase. • Validation of the method in terms of sensitivity, linearity, and matrix effects in four different matrices: tomato, orange, onion and quince. • Improvement of the retention time robustness, Graphical abstract Image, graphical abstract

Using reclaimed water to irrigate crops can be an important route for organic contaminants of emerging concern (CECs) to be introduced into agricultural production and thus find their way into the food chain. This work aims to establish accumulation models for the different parts of a crop (fruit/leaves/roots) and the soil of some of the most commonly detected CECs in reclaimed water, through field trials in greenhouses. For this, tomato plants were permanently irrigated under realistic agricultural conditions with a mixture of the selected compounds at approx. 1 μg/L. A total of 30 contaminants were analyzed belonging to different compound categories. A modified QuEChERS extraction method followed by liquid chromatography coupled to tandem mass spectrometry was the procedure used. The study revealed the presence of 21 target contaminants in the tomatoes, and 18 CECs in the leaves, roots, and soil. The average total concentration of pesticides detected in the tomatoes was 3 μg/kg f.w., whereas the average total load of pharmaceuticals was 5.8 μg/kg f.w. after three months, at the time of crop harvesting. The levels of pharmaceutical products and pesticides in the non-edible tissues were up to 3.5 and 2.1 μg/kg f.w., respectively, in the leaves and up to 89.3 and 31.3 μg/kg f.w., respectively, in the roots. In the case of the soil samples, the pesticide concentration found after crop harvesting was below 11.4 μg/kg d.w., and less than 3.0 μg/kg d.w. for pharmaceuticals. Overall, the concentration levels of CECs detected in the tomatoes, which were permanently irrigated with contaminated reclaimed water, do not pose a risk to human health via dietary intake., This work was supported by the Spanish Ministry of Science, Innovation and Universities (MICINN) as part of Project “ROUSSEAU” (CTM2017-89767-C3-3-R). M. García-Valverde acknowledges the pre-doctoral fellowship associated to the project (PRE2018-087072). Dr. María del Mar Gómez Ramos acknowledges funding obtained for a research contract from the European Social Fund 2014–2020 and the Ministry of Health, Andalusian Regional Government.

Microplastics are ubiquitous and their sampling is a difficult task. Honeybees interact with the environment inside their foraging range and take pollutants with them. In this work, we demonstrated for the first time that worker bees can act as active samplers of microplastics. We collected honeybees from apiaries located in the centre of Copenhagen and from nearby semiurban and rural areas. We showed the presence of microplastics in all sampled locations mostly in the form of fragments (52%) and fibres (38%) with average equivalent diameter of 64 ± 39 μm for fibres and 234 ± 156 μm for fragments. The highest load corresponded to urban apiaries, but comparable number of microplastics was found in hives from suburban and rural areas, which can be explained by the presence of urban settlements inside the foraging range of worker bees and to the easy dispersion of small microplastics by wind. Micro-FTIR analysis confirmed the presence of thirteen synthetic polymers, the most frequently of which was polyester followed by polyethylene and polyvinyl chloride. Our results demonstrated the presence of microplastics attached to the body of the honeybees and opens a new research pathway to their use as active biosamplers for anthropogenic pollution, The authors acknowledge the financial support provided by the Spanish Government: CTM2016-74927-C2-1-R/2-R, and the Thematic Network of Micro- and Nanoplastics in the Environment (RED2018-102345-T, EnviroPlaNet Network). CE thanks the Spanish Ministry of Science, Innovation and Universities for the award of a pre-doctoral grant (FPI)

Identification and quantitative determination of analytes released from food contact materials (FCMs) is still an analytical challenge for scientists since neither chemical nor spectral databases nor analytical standards are available. Gas and liquid chromatography hyphenated to a variety of accurate mass analyzers based on the use of high-resolution have been used for this purpose. In this review, we present an overview of current approaches based on high resolution accurate mass spectrometry (HRAMS) analysis, particularly based on software tools for data acquisition and data processing used for the identification of unknown migrants coming from plastic FCMs. The main advantages and disadvantages of identification strategies have been put into evidence. A summary of the different intentionally and non-intentionally added substances identified or tentatively identified in plastic FCMs using HRAMS analysis has also been presented. Finally, we discuss the main current risk assessment strategies for food packaging migration studies found in the literature.

EU legislation requires that chemicals migrating from food packaging into food do not endanger human health. A proper safety assessment must go further than simply testing for known ingredients used to make the packaging materials. The identification of all potential migrants, including non-intentionally added substances (NIAS), is required to assess the safety of these materials. In this study, the benefits of using LC-ESI-Q-TOF-MS equipment combined with the data-independent acquisition method SWATH (Sequential Windowed Acquisition of All THeoretical MS) have been evaluated for the identification of unexpected migrants from multilayer plastic packaging materials. Identification of non-target peaks followed by filtering strategies facilitated the comprehensive identification procedure of unexpected migrants present in the food simulants. MS and MS/MS data from the most abundant ions in the samples were processed using formula finding and searched against open chemical and spectral databases, such as ChemSpider and METLIN, combined with bibliographic search. This approach has allowed the identification of 26 potential migrants, of which 23 were NIAS. Cyclic oligomers, possibly coming from polyurethane adhesives, were the main migrants in the studied materials. Evaluation of the toxicity of the tentatively identified migrants was carried out, showing that most of them were classified in the higher toxicity class according to Cramer rules. Most of the compounds detected in this study were previously reported in other studies of NIAS migration from plastic packaging materials, except for five of the tentatively identified oligomers that were found for the first time in this study. This study shows the high potential of non-targeted approaches using high resolution accurate mass spectrometry (HRAMS) with SWATH acquisition for the characterization of food packaging materials aimed at food safety evaluation.

Two straightforward methods for glyphosate and AMPA analysis in honey through ion chromatography coupled to Q-Orbitrap accurate high-resolution mass spectrometry as well as their application to real samples are presented. The sample preparation step is accomplished through dilution with methanol–water or water. No pH adjustment is necessary. Recoveries were in the range 80 to 110% with RSDs < 20%. The LOQ of glyphosate was 0.005 mg kg−1, far below the allowed EU-MRL (0.05 mg kg−1) in honey, showing a linear range of 0.005–0.5 mg kg−1 and medium matrix effect. LOQ of AMPA was 0.02 mg kg−1. Glyphosate quantitation was performed with internal or external calibration yielding identical results, thus broadening the applicability of the method as isotopically labelled standards are no longer mandatory. The method was applied to 32 honey samples from different origins. Glyphosate was found in 81% of the samples and 41% were above the EU-MRL showing its applicability in routine work. AMPA was not detected in any of the samples.

Highlights • Occurrence of pesticide residues in organic samples is approximately 5 times lower than in conventional. • The impact of analytical methods with low LOQs (, In the last decade, the consumption trend of organic food has increased dramatically worldwide. Since only a few pesticides are authorized in organic crops, concentrations are expected to range at zero or ultra-trace levels. In this context, the aim of the present study was to investigate the need for an improvement in the residue controls at very low concentrations (

Spices are known as difficult matrices that contain variable amounts of fats, piperine or many other matrix constituents. The increasing sensitivity of new GC–MS/MS platforms opens new approaches to analyze pesticide residue in complex matrices such as spices, by sample dilution. The aim of this work is to develop and validate an effective multiresidue method for the analysis of pesticide residues in spices by GC–MS/MS. In this paper, we highlight the importance of reducing matrix interferences generated from co-extractive components of spices. Moreover, we emphasize the concern of obtaining clean extracts requiring less instrument maintenance. By evaluating the total ion chromatograms (TIC) on GC-Orbitrap-MS of different extracts using various sorbents, QuEChERS citrate using EMR-Lipid sorbent resulted in the cleanest extract among Z-Sep, Primary secondary amine (PSA), Oasis® Prime HLB, and Supelclean™ Ultra cartridges that consist of a top bed of PSA, C18 and Grashsphere™ 2031 and a bottom bed of Z-Sep. Later, the analyses were performed on a GC-QQQ-MS/MS, applying a 15 min runtime method covering 205 compounds. The samples were diluted 25 times before the injection bearing in mind that the instrumental LOQs reached (iLOQ) were 2 ng g−1 and the method LOQs (mLOQ) were 50 ng g−1. Good recoveries between 70 and 120% with RSDs lower than 20% were observed for 90% of the compounds in black pepper and for 83% of the compounds in cayenne pepper. To demonstrate the applicability of the proposed method, 50 real dried and non-dried spice samples were analyzed. The most detected pesticides were metalaxyl, chlorpyrifos, tebuconazole, ethion, and chinomethionate.

In this study, honeybee colonies were monitored in a field study conducted on sunflowers grown from seeds treated with the systemic neonicotinoids thiamethoxam or clothianidin. This field trial was carried out in different representative growing areas in Spain over a beekeeping season. The health and development of the colonies was assessed by measuring factors that have a significant influence on their strength and overwintering ability. The parameters assessed were: colony strength (adult bees), brood development, amount of pollen and honey stores and presence and status of the queen. The concentration of residues (clothianidin and thiamethoxam) in samples of beebread and in adult bees was at the level of ng.g−1; in the ranges of 0.10–2.89 ng g−1 and 0.05–0.12 ng g−1; 0.10–0.37 ng g−1 and 0.01–0.05 ng g−1, respectively. Multivariate models were applied to evaluate the interaction among factors. No significant differences were found between the honeybee colonies of the different treatment groups, either exposed or not to the neonicotinoids. The seasonal development of the colonies was affected by the environmental conditions which, together with the initial strength of the bee colonies and the characteristics of the plots, had a significant effect on the different variables studied.

In this work, 260 pesticide residues, including insecticides, acaricides, fungicides, and herbicides, were extracted from honeybees using the QuEChERS methodology modified by applying an ultrasonic probe, which avoided the homogenization step and reduced the extraction time. Gas and liquid chromatography, both coupled to triple-quadrupole mass spectrometry, allowed the determination of the pesticide residues extracted from the samples. The optimization of the main ultrasonic conditions (sonication amplitude, number of cycles, and time of each cycle) was performed using a Box-Behnken experimental design involving 15 experimental samples. The results obtained with this approach showed that the recoveries were not affected by these experimental parameters for 95 pesticide residues whereas the sonication amplitude was the main factor affecting the recoveries of 107 pesticide residues. The extraction time and the number of cycles affected four and one pesticide residues, respectively. The effectiveness of the ultrasonic-assisted extraction without homogenization of the honeybee samples compared favorably with that for the conventional QuEChERS methodology applied to the same previously homogenized samples. The proposed methodology was validated according to the SANTE/11945/2015 guidelines, with a 5 μg/kg limit of quantitation. Recoveries between 70 and 120% and relative standard deviations lower than 20% were obtained for most analytes. Thirty honeybee samples taken from Spanish apiaries were analyzed using this new methodology. The results revealed the presence of 30 different pesticide residues in the honeybee samples, the highest concentration levels corresponding to certain insecticides/acaricides used by beekeepers to control Varroa destructor. Permethrin, thiabendazole, carbendazim, and coumaphos were the most frequently detected pesticide residues in the selected samples.

Supercritical fluid chromatography coupled to triple quadrupole mass spectrometry has been evaluated for pesticide residues in food. In order to check its advantages and limitations it was developed a method to identify and quantify 164 pesticides in three different matrices (tomato, orange and leek). A carbon dioxide gradient with methanol (containing 1 mM ammonium formate) was used allowing a flow rate of 1.5 mL/min that made the total run time of 12 min without any problem of overpressure. Addition of a post column flow 150 μL/min of Methanol with ammonium formate/formic acid was necessary to improve the ionization. The matrix effect study revealed that the percentages of pesticides with irrelevant matrix effect (suppression lower than 20%) was 99% in tomato, 87% in orange and 62% in leek, whereas significant suppression (higher than 50%) was not found in tomato and only 1% of the compounds in orange and 3% in leek.These results compare favorably with that typically obtained in LC–MS/MS. The absence of water in the mobile phase, also provided some important advantages regarding LC–MS/MS as (i) higher retention of polar compounds in the column, which elute with high sensitivity and good peak shape and (ii) a general increase of the sensitivity of the analysis, consequence of the high ionization and ion extraction efficiency. Pesticides evaluated were identified following the SANTE/11813/2017. At the spiking concentration of 5 μg/kg, 98% of the pesticides were identified in tomato, 98% in orange and 94% in leek, whereas for the concentration of 10 μg/kg all the compounds were identified in tomato and only spiromesifen was not identified in orange and leek. At the concentration of 20 μg/kg, spiromesifen was also identified in these two matrices. The linearity and reproducibility of the method were evaluated with results which guarantee high quality in the analytical measurements. Even though only 2 μL of final extract were injected, the sensitivity of the SFC method was enough to achieve stringent LOQs.Real samples, including 6 different fruits and vegetables, were analyzed by the SFC-MS/MS proposed method, the results being similar to those obtained by LC–MS/MS. The method was also applied to a proficiency test of fipronil in eggs with good results in all the cases. Carbon dioxide as mobile phase with methanol as modifier can represent a good alternative to LC–MS/MS with reduction of matrix effects and shorter run times.

Ion chromatography coupled to a quadrupole Orbitrap mass analyzer was used to develop a multiresidue method for the determination of highly polar pesticides and their metabolites (chlorate, perchlorate, fosetyl-aluminum, glyphosate, aminomethylphosphonic acid (AMPA), phosphonic acid, N-acetyl AMPA, and N-acetyl glyphosate) in fruits and vegetables. After extraction with methanol, samples were diluted 5× with water. No derivatization was applied. Pesticides were separated in an anion-exchange column. Water was used as the ion chromatography mobile phase. A gradient was created by increasing the concentration of KOH in the mobile phase. Ion chromatography provided good and stable retention and separation for all studied compounds. All investigated pesticides had an LOQ of 0.01 mg/kg and a linear range of 0.01–0.50 mg/kg. The ion ratio of the m/z ions produced was stable and adequate (deviation 100 000) provided by the Orbitrap analyzer with the low m/z ions obtained (e.g., m/z 80) was effective in obtaining low background matrix signals. The influence of postcolumn infusion of organic solvent on sensitivity was investigated. Acetonitrile was found to be more effective than methanol, increasing the sensitivity 3× with respect to water. The method was validated for five vegetable-based matrixes. Both the sample processing and the analytical measurement were very fast. Hence, the methodology is ideal for high-throughput work.

This paper presents an efficiency evaluation of GC coupled with quadrupole Orbitrap MS for identification and quantitation in the multiresidue pesticide analysis of baby foods in full-scan mode. The identification criteria were studied following SANTE guidelines (retention time, mass accuracy, and ion ratio), comfortably complying with the values established, even at 0.003 mg/kg. Method validation was carried out on 15 selected GC-amenable pesticides covered by Commission Directive No. 2006/125/EC in three different baby food matrixes. Recovery studies were performed at 0.003 and 0.006 mg/kg, with 96% of the cases falling within the 70–120% range and with RSDs 0.995. In general, matrix effect values were >100%. The LOQ was 0.003 mg/kg for 97% of the cases. The validated method was applied to 20 real baby food samples from Spain and to the European Union Proficiency Test FV-BF01 sample, in which the z-scores obtained were

Pesticide residue analysis in olive oil presents difficulties due to the high amount of co-eluted compounds resulting in high matrix effect. Different extraction/clean-up methods including gel permeation chromatography, liquid/liquid extraction, solid-phase extraction and other extraction methods are applied to overcome these difficulties. Recent approaches such as the addition of the freezing-out step and the application of Enhanced Matrix Removal-Lipid sorbent (EMR-Lipid) are reported. Gas chromatography and liquid chromatography coupled to mass spectrometry are considered the gold standard technologies covering a wide scope of pesticides. This review recapitulates the methods most widely used for the determination of pesticide residues in vegetable oils. As a continuation of previous reviews, the work conducted is an update review of methods from 2006 in this field, evaluating their strengths and limitations. Main analytical parameters of the different extraction procedures and detection methods are discussed in terms of recoveries, robustness, limit of quantification, and matrix effect.

The efficiency of a data independent acquisition by the sequential window acquisition of all theoretical fragment ions (SWATH®) in high resolution accurate mass spectrometry was evaluated for pesticide residue analysis. Selection of various mass range windows over 100–950 Da was studied to produce MS/MS spectra with selectivity improvement. The number of mass windows selected was restricted to ten to avoid excessive scanning MS/MS time that can produce a very low number of points per chromatographic peak. The SWATH workflow was demonstrated to be effective in reducing the number of interferents in the MS/MS spectrum allowing compliance with the ion ratio (±30%) of the intensity of the precursor vs. fragment ion and mass errors ≤ 5 ppm in all cases studied. Two applications of this methodology were investigated: (a) baby foods, focusing on the analysis of 15 LC-amenable pesticides for which the European legislation establishes strict MRL levels (0.003 mg kg−1) and (b) eggs, evaluating the presence of fipronil, fipronil sulfone, fipronil desulfinyl and fipronil sulfide. This last application was in line with the interest due to the recent rapid alert on the presence of fipronil in eggs (RASFF Portal in the EU, July 2017). The analytical approaches proposed yielded a very good linearity in the range of 0.003–0.200 mg kg−1 (baby food) and 0.001–0.250 mg kg−1 (eggs), and reproducibility < 20% allowing conclusive identification and reliable quantification of selected analytes at the EU MRL levels. The evaluation of the identification and quantitation capabilities of the instrument was performed through the analysis of real samples and a Proficiency Test (PT) sample for both baby foods and eggs.

A fast and sensitive method was validated for the analysis of pesticide residues in baby food. After an QuEChERS-based extraction, the samples were analysed with a dual-channel liquid chromatography instrument coupled to a triple quadrupole mass spectrometer. The method consisted of two independent injections per sample. In the first injection the sample was analysed with a mobile phase optimal for the positive polarity ionisation (water, methanol, formic acid, and ammonium formate), whereas in the second injection the mobile phase was optimised for the negative polarity ionisation (water, acetonitrile, acetic acid). The total number of pesticides was 264, out of which 238 were analysed with the methanol gradient and 26 with the acetonitrile gradient. The dual-channel instrument allowed for sample multiplexing. Thus, sample throughput was equivalent to that of a single-channel system. The limit of quantitation, determined according to the DG SANTE guidance document, was 0.003 mg/kg for 97% of the evaluated compounds. The validation study was followed by a real sample survey. In 42 samples, 16 positives were found.

The European Union Reference Laboratory for pesticide residues in Fruits and Vegetables (EURL-FV) is organising, every year since 2004, the European Commission Proficiency Test for multiresidue analysis of pesticides in fruits and vegetables (EUPT-FV), which is directed to all National Reference Laboratories (NRLs) and all Official Laboratories (OfLs) responsible for pesticide residue control in the European Union. This work provides an updated overview of the last eight editions of EUPT-FV (2009–2016), highlighting the main difficulties encountered by the participant laboratories and the key achievements in the field of sample extraction and data dispersion and statistical evaluation. The number of participant laboratories was every year increasing from 151 in 2009 (EUPT-FV11) to 191 in 2016 (EUPT-FV18), and the total number of pesticide residue results reported by the laboratories in this period was close to 18,000. The percentage of acceptable, questionable and unacceptable z scores values assigned in each one of these eight EUPT-FVs has remained very similar with average values of 91.8, 3.5, and 4.7 percent, respectively. The large amount of data results evaluated has led to a strengthening in the use of the 25 percent fit-for-purpose relative standard deviation (FFP-RSD) as well as the use of an internationally accepted 50 percent target expanded measurement uncertainty default value when reporting results for multiresidue analysis of pesticides.

Gas and liquid chromatography coupled to triple quadrupole tandem mass spectrometry are currently the most powerful tools employed for the routine analysis of pesticide residues in food control laboratories. However, whatever the multiresidue extraction method, there will be a residual matrix effect making it difficult to identify/quantify some specific compounds in certain cases. Two main effects stand out: (i) co-elution with isobaric matrix interferents, which can be a major drawback for unequivocal identification, and therefore false negative detections, and (ii) signal suppression/enhancement, commonly called the “matrix effect”, which may cause serious problems including inaccurate quantitation, low analyte detectability and increased method uncertainty. The aim of this analytical study is to provide a framework for evaluating the maximum expected errors associated with the matrix effects. The worst-case study contrived to give an estimation of the extreme errors caused by matrix effects when extraction/determination protocols are applied in routine multiresidue analysis. Twenty-five different blank matrices extracted with the four most common extraction methods used in routine analysis (citrate QuEChERS with/without PSA clean-up, ethyl acetate and the Dutch mini-Luke “NL” methods) were evaluated by both GC-QqQ-MS/MS and LC-QqQ-MS/MS. The results showed that the presence of matrix compounds with isobaric transitions to target pesticides was higher in GC than under LC in the experimental conditions tested. In a second study, the number of “potential” false negatives was evaluated. For that, ten matrices with higher percentages of natural interfering components were checked. Additionally, the results showed that for more than 90% of the cases, pesticide quantification was not affected by matrix-matched standard calibration when an interferent was kept constant along the calibration curve. The error in quantification depended on the concentration level. In a third study, the “matrix effect” was evaluated for each commodity/extraction method. Results showed 44% of cases with suppression/enhancement for LC and 93% of cases with enhancement for GC.

In the last 10 years, the majority of the pesticide food control laboratories moved from GC-MS to GC-MS/MS as the preferred analytical technique to address GC amenable compounds. The main reason for this change was the negative impact on the single stage GC-MS analysis caused by the interference from coeluting matrix compounds. The new development of gas chromatography coupled to high resolution accurate mass spectrometry (GC-HRAMS) provides opportunities to overcome such matrix interferences as a result of its much higher selectivity; allowing laboratories to carry out full-scan analysis covering the most exigent analytical performance criteria. The aim of this work is the evaluation of the main analytical performance parameters for the multiresidue screening of pesticide residues by a gas chromatography-Orbitrap™ mass spectrometer in fruits and vegetables. Electron ionization and full-scan high resolution mass spectrometry was selected for this evaluation. Mass resolving power, selectivity, sensitivity, analyte identification and database generation are discussed in light of the analysis of various commodities and a large scope of pesticides. The selected operational conditions provided optimal mass accuracy, within ±1mDa and achieved LOQs of 10μg/kg or lower for practically all the selected pesticides and commodities. Applicability for quantitative residue analysis was verified by the validation of the 210 pesticides in four matrices (tomato, apple, leek and orange). The performance of the GC-EI-full scan Orbitrap HRAMS developed method was confirmed with the analysis of 102 real samples providing good results.

The influence of genetic diversity and exposure to xenobiotics on the prevalence of pathogens was studied within the context of a voluntary epidemiological study in Spanish apiaries of Apis mellifera iberiensis, carried out during the spring season of years 2014 and 2015. As such, the evolutionary lineages of the honey bee colonies were identified, a multiresidue analysis of xenobiotics was carried out in beebread and worker bee samples, and the Toxic Unit (TUm) was estimated for each sampled apiary. The relationship between lineages and the most prevalent pathogens (Nosema ceranae, Varroa destructor, trypanosomatids, Black Queen Cell Virus; and Deformed Wing Virus) was analysed with contingency tables, and the possible relationships between TUm and the prevalence of these pathogens were studied by using a factor analysis. The statistical analysis supported the associations between V. destructor and Deformed Wing Virus (DWV), and between N. ceranae and Black Queen Cell Virus (BQCV), but the association between these pathogens and trypanosomatids was not observed. TUm values varied between 5.5 × 10−6 and 3.65 × 10−1. When TUm 10% in the 63% of the cases. The prevalence of pathogens did not appear to be influenced by the distribution of evolutionary lineages and, while the prevalence of V. destructor was not found to be determined by TUm, there was a trend towards an increasing prevalence of N. ceranae when TUm ≥ 23 10−4. This study is an example of using TUm approach beyond the field of the ecotoxicology.

In the present study, a batch mode procedure has been developed to remove pesticides from beeswax coming from bee farms. The beeswax is treated by an Extraction Process with methanol at 65 °C followed by an Adequation Process with water at 70 °C. This procedure can reduce the beeswax contamination load by values of around 80% – 90% for the acaricides usually present in beeswax such as Coumaphos, Chlorfenvinphos, tau-Fluvalinate and Acrinathrin, at concentration ranges of 1800 – 2600 μ g/kg, 140 – 300 μ g/kg, 100 – 300 μ g/kg and 160 – 470 μ g/kg, respectively. This process is also able to eliminate other pesticides, such as Amitraz, which are typically present in beeswax samples at high concentrations. Similarly, it is efficient in removing further compounds such as Propiconazole, Bromopropylate, Chlorpyrifos, Cypermethrin, Diazinon and Fenamiphos, which are present at lesser quantities depending on their origin and surrounding pesticide treatment history. The procedure’s operating parameters were atmospheric pressure, a 20 °C – 70 °C temperature range and 200 rpm. Up to 80% of the methanol used in the extraction was recycled and the waste generated was easy to manage. The quality of the decontaminated beeswax obtained has similar properties to those of virgin beeswax and can be used to manufacture ecological hives or galenic formulations. Beeswax quantities of 1, 20 and 75 kg were treated to determine the optimal operating conditions that would make it possible to extend the process to the industrial scale. All the equipment utilized (e.g. agitated tanks, temperature control, centrifuges and distillation equipment) are basic tools commonly used in the chemical industry.

LC-Q-Orbitrap efficiency was evaluated for pesticide multi-residue analysis by using three workflows involving simultaneous MS and MS2 analysis. They were as follows: data-dependent MS2 (dd-MS2), all-ion fragmentation (AIF) and variable data-independent analysis (vDIA). These MS2 workflows were tested for the main method validation parameters such as detection and identification capabilities, repeatability, linear range and quantitation. QuEChER acetonitrile extracts (blanks and spiked with 166 pesticides) of 11 different fruits and vegetables were used for this evaluation. Blank extracts were analysed to evaluate isobaric compounds and potential false identification. Spiked extracts (at 0.01 and 0.1 mg kg−1) were analysed to evaluate the false negatives potentially produced (considering a retention mass window of 0.2 min). At 0.01 mg kg−1, dd-MS2 had the highest identification rate (96–100%, depending on the matrix). In vDIA, it was 86–100% and in AIF 81–100%. But these two last workflows offered more possibilities for applying screening analysis. It was observed that application of the ion ratio criterion established in the SANTE Guidelines for identification can generate some artificial false negative results. It could be overcome by considering a mass error threshold (i.e. 5 ppm) as a selected criterion. Detection and quantitation were carried out in full-scan MS. MS2 data were used for identification. Dd-MS2 provided the highest number of points per chromatographic peak, and by that peak area, repeatability was the best (typically

In this study, composite polysulfone–polyvinylpyrrolidone (PSU–PVP) membranes were prepared using silver and copper loaded sepiolite as a filler. Metal-loaded sepiolite was evenly dispersed within the membranes. No leaching of metal particles was observed during use and only dissolved metals were responsible for membrane antimicrobial activity. The membranes displayed high antibacterial activity showing surfaces free of bacterial colonisation (