Dissipation, processing factors and dietary risk assessment of the bioinsecticide abamectin in herbal plants belonging to Lamiaceae family from open field to herbal tea infusion.

Abamectin, the mixture of avermectin B1a and B1b, is widely used as a bioinsecticide and is an alternative to chemical pest control from insects. To our knowledge, its behaviour is not fully recognized, especially in herbs. Thus, the objective of this study was to investigate the environmental fate of abamectin in herbal plants belonging to the Lamiaceae family, its dissipation in open field studies laboratory processing treatments and dietary risk assessment. Three medicinally and culinary important species of herbs: Melissa officinalis L., Mentha × piperita L. and Salvia L. were treated with single and double dose than recommended on the label during their cultivation (BBCH 11-29). Residues were monitored using the QuEChERS method followed by the LC-MS/MS. The dissipation pattern of the sum of avermectin B1a and B1b and their persistence were observed 14 d after spraying. Abamectin decline was very rapid in plants and followed the first-order kinetics model. The half-life (t1/2) was in the range of 0.96-1.08 d (single dose) and 0.93-1.02 d (double dose). The pre-harvest intervals (decrease to the level of 0.01 mg kg-1) were 7.29-7.92 d at single and 7.99-8.64 d at double dose application. Herbal infusion preparation in previously washed and dried mint, lemon balm and sage leaves was the key processing step in the removal of abamectin residues. The reduction of initial deposits after single dose treatment was noted up to 65% (PF = 0.35-0.67) and up to 79% after double dose application (PF = 0.21-0.72) in herbal tea. Acute risk assessment of children and adults for the highest residues in EFSA PRIMo model at single and double dose expressed as hazard quotients (HQ) were <1, indicating no risk to humans via consumption of the herbal products. The data provide a better understanding of abamectin behaviour in herbal plants and can help assure herbs' safety for consumers.

Removal of triazole and pyrethroid pesticides from wheat grain by water treatment and ultrasound-supported processes.

A simple way to reduce pesticides in cereal grains is to use washing methods. The challenge of this study was to evaluate the effectiveness of reduction of 3 triazole fungicides (difenoconazole, tebuconazole, tetraconazole) and 3 pyrethroid insecticides (beta-cyfluthrin, cypermethrin, deltamethrin) commonly used in wheat protection. Four different pre-washing methods (hot and cold water washing, twice water, and ultrasound-supported washing) were evaluated. The processing factor (PF) was calculated based on the concentration of pesticides determined by LC-MS/MS in the samples of cereal grains before and after the washing process. PFs were within the range 0.01-0.97. Time, teperature and ultrasound were factors influencing the efficiency of water treatment. The study showed that ultrasound-supported washing eliminated pesticide residues to a greater extent than ordinary washing. This process significantly affected or completely reduced concentrations of triazoles in wheat grains. The highest reduction of residues (99%) was received for tebuconazole and ultrasound washing with heating temperature of 60 °C for a total of 10 min. In all washing processes, pyrethroids were removed with lower efficiency than triazoles. The lowest residue reduction was obtained for cypermethrin and washing under cold water for 5 min (3%; PF = 0.97). Beta-Cyfluthrin showed only a 6-27% reduction regardless of the process (PF: 0.73-0.95). Using static analysis, the relationship between the properties of pesticides and the reduction of their concentration in cereals was clarified and showed a strong correlation.

Impact of technological processes on tebuconazole reduction in selected cereal species and the primary cereal product, and dietary exposure assessment.

Contamination of cereals with tebuconazole (TEB) can affect the dietary risk assessment. This study investigates, for the first time, how mechanical, thermal, physical-chemical, and biochemical processes affect the TEB level in wheat, rye, and barley. The biochemical process of malting was the most effective for tebuconazole reduction (by 86%) in cereals. Thermal processes were also effective, i.e., boiling (70%) and baking (55%). These processes considerably decreased the concentration of tebuconazole, and Procesing Factors (PFs) were from 0.10 to 0.18 (malting), 0.56 to 0.89 (boiling), and 0.44 to 0.45 (baking), respectively. The concentration of TEB was not reduced after the application of mechanical processing. The risk was estimated in dietary exposure assessment on the basis of the highest reported levels of tebuconazole residues bread. At a high level of rye bread consumption, the potential exposure to tebuconazole reached only 3.5% and 2.7% in children and adults, respectively.

A global study of pesticides in bees: QuEChERS as a sample preparation methodology for their analysis - Critical review and perspective.

To this day, it remains unknown what the cause of decline of honey bee populations is and how to prevent this phenomenon efficiently. Poisonings with pesticides are assumed to be among the main causes for the decline of the honey bee population. Despite the significant progress observed in analytics over recent years, research aimed at improving methods applied in diagnostics of bee poisoning is still in progress. This is no easy task, since determination of the content of trace amounts (often equal to sublethal doses) of a wide range of compounds with diverse physico-chemical properties in honey bee samples with a complex matrix composition poses a serious challenge to modern analytics. This overview is the first to include a comprehensive critical assessment of analytical methods proposed for quantification of pesticides in honey bees over the last decade. Since the QuEChERS method is currently of great significance to ensuring accurate and reliable results of pesticide quantification in honey bees, the present overview focuses on the major aspects of this method, which will provide a comprehensive reference for scientists. The review focuses on the limitations of methods and on potential future prospects. It also contains information on the detection of pesticides in honey bees between 2010 and 2020 and characterizes the pesticide classes which are most toxic to these insects. This is extremely important, not just in the context of understanding the potential adverse impact of pesticides, manifesting as losses in bee colonies; it is also intended to facilitate decision-making in future research related to this difficult yet very important subject.

Impact of broad-spectrum pesticides used in the agricultural and forestry sector on the pesticide profile in wild boar, roe deer and deer and risk assessment for venison consumers.

The present work is the first extensive study of large-scale pesticides research in wild animals. The investigation covered three game species: wild boar (n = 42), roe deer (n = 79) and deer (n = 15) collected from north-eastern Poland. To characterize the 480 pesticides in muscle samples, LC-GC-MS/MS techniques were used. A total of 28 compounds were detected: 5 neonicotinoids, 6 organochlorine and 5 other insecticides, 9 fungicides and 4 herbicides, in the range of 0.1-85.3 ng g-1. Over four hundred detections were done. The highest mean concentrations were as follows: anthraquinone (85.3 ng g-1) > DDT-p,p' (4.6 ng g-1) > imidacloprid (4.3 ng g-1) > permethrin (3.6 ng g-1) > thiacloprid (2.8 ng g-1). DDT and metabolites were the most frequently detected, followed by acetamiprid, tebuconazole, clothianidin and imidacloprid. Overall, 92% samples with residues were recorded, including 100% of wild boar, 88% of roe deer and 86% of deer. More than one pesticide (up to 9) was found in over 73% of the tested samples. The estimated chronic and acute risk to consumers of venison were very low (below 1% ADI and ARfD). This interdisciplinary study may be helpful for estimating ecological risk to wild animals and risk to consumers of wild animal products, and also as a source of biomonitoring data.

Exposure of wild boars (Sus scrofa L) to neonicotinoid insecticides.

The aim was to determine, for the first time, concentrations of 7 neonicotinoids (NEOs) and 5 metabolites in Sus scrofa from hunting areas in north-eastern Poland and assess the risk to consumers eating boar meat. 42 wild boar muscle samples were collected over a one-year period. The concentrations of 12 NEOs were determined by a fully validated LC-ESI-MS/MS protocol based on ultrasonic, freezing and cleanup EMR-lipid sample preparation. NEOs were present in over 83% of samples, 17% had no residue, and one pesticide was present in 36% of samples. Most often found were: clothianidin (35%), acetamiprid and imidacloprid (33%), thiacloprid (31%), thiamethoxam (9%), and the average concentrations were (ng g-1): thiacloprid 6.2 > imidacloprid 5.7 > acetamiprid 4.6 > clothianidin 2.2 > thiacloprid 1.6 > thiamethoxam 1.0. Multi-residue samples were found, one with 7 and one with 5 NEOs. Two NEOs were present in 24%; 3 in 39% and 4 in 10% of samples. In the metabolic degradation of acetamiprid, imidacloprid and thiacloprid, it was observed that metabolites account for no more than 8.5% of the measured parent substance. Acetamiprid-n-desmethyl was noted most often (21%). Due to the detection of NEOs in a large proportion of samples, chronic and acute risk assessment were performed. The estimated chronic and acute risk for consumers from NEOs neonicotinoids through the consumption of wild boar was very low and amounted to respectively 0.02% of ADI and 0.86% of ARfD.

Development of precise micro analytical tool to identify potential insecticide hazards to bees in guttation fluid using LC-ESI-MS/MS.

This paper illustrates the development of a miniaturized and precise analytical tool for biomonitoring of honey bee exposure to insecticides. This is the first work describing an analytical method for determination of very low concentrations of a wide range of insecticides in maize guttation fluid. Seed treatment with systemic insecticides or their foliar application causes the accumulation of compounds in the guttation liquid, which consists of excess water and compounds removed by plants and is a source of water for bees. A micro-QuEChERS protocol using 1 g of sample was used for analysis of over 140 insecticides belonging to 30 different chemical classes by LC-ESI-MS/MS. The determination of insecticides in guttation fluid is a difficult analytical task due to 1) the complexity of the sample matrix, 2) small amounts of test samples and 3) trace levels of analytes (often equal sublethal dose of insecticide for bees). An efficient sample treatment is proposed, involving 1 g of sample, extraction with 1% formic acid in acetonitrile, frozen, ultrasound-assisted, centrifugation and dispersive solid phase extraction with nano graphene oxide. Other tested sorbents: Fe3O4MNPs and two mixtures PSA/C18/GCB and Z-Sep did not give satisfactory parameters during sample purification. The graphene oxide proved to be the best, ensuring negligible matrix effects and analyte recoveries between 70% and 120% with relative standard deviations <20% for most of the compounds studied. The proposed method enables assessment of risk to honey bees resulting from exposure to guttation fluids containing toxic insecticides at very low concentrations.

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

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

Dissipation of S-metolachlor in plant and soil and effect on enzymatic activities.

The present study aimed at evaluating the dissipation of S-metolachlor (S-MET) at three doses in maize growing on diverse physico-chemical properties of soil. The effect of herbicide on dehydrogenase (DHA) and acid phosphatase (ACP) activity was estimated. A modified QuEChERS method using LC-MS/MS has been developed. The limit of quantification (0.001 mg kg-1) and detection (0.0005 mg kg-1) were very low for soil and maize samples. The mean recoveries and RSDs for the six spiked levels (0.001-0.5 mg kg-1) were 91.3 and 5.8%. The biggest differences in concentration of S-MET in maize were observed between the 28th and 63rd days. The dissipation of S-MET in the alkaline soil was the slowest between the 2nd and 7th days, and in the acidic soil between the 5th and 11th days. DT50 of S-MET calculated according to the first-order kinetics model was 11.1-14.7 days (soil) and 9.6-13.9 days (maize). The enzymatic activity of soil was higher in the acidic environment. One observed the significant positive correlation of ACP with pH of soil and contents of potassium and magnesium and negative with contents of phosphorus and organic carbon. The results indicated that at harvest time, the residues of S-MET in maize were well below the safety limit for maize. The findings of this study will foster the research on main parameters influencing the dissipation in maize ecosystems.

Evolution of novel sorbents for effective clean-up of honeybee matrix in highly toxic insecticide LC/MS/MS analysis.

Highly toxic insecticides (HTIs) belonging to different chemical groups are dangerous to pollinating organisms, even in sublethal doses. An important objective of this study was to develop a method to determine over fifty HTIs at very low concentrations in the bee matrix. The novelty of this research involved obtaining extract completely free from beewaxes, lipids and proteins using EMR-lipid (enhanced matrix removal-lipid), chitin and Z-Sep+ (zirconium oxide and C18 dual-bonded to silica) as clean-up sorbents. Different parameters, such as weight of bees, extraction solvent, and freezing time were evaluated. Determinations were made using liquid chromatography-tandem mass spectrometry (LC-MS/MS). EMR-lipid allows for removing most of the fatty co-extracts and increases the overall performance of the method by reducing the matrix effects (ME) without significant analyte loss. The established modified QuEChERS method based on 1% acetic acid in acetonitrile extraction followed by EMR-lipid clean-up was validated at three different spiking levels (0.001, 0.01 and 0.1mgkg-1). Precision, calculated as relative standard deviation (RSD), was below 20%. The proposed method was used to determine sublethal doses of these insecticides in real samples of dead honeybees.

Behaviour of mesotrione in maize and soil system and its influence on soil dehydrogenase activity.

The aim of this study was to investigate the dissipation of mesotrione and effect on dehydrogenase activity (DHA) in maize and soil system. The paper for the first time describes behaviour of this herbicide applied at various doses (separately or in mixture with other herbicide) in acidic and alkaline environment. The experiments were conducted using the method randomized blocks in four repetition cycles. Chemical application in seven variants at recommended doses of herbicide were performed. The sample preparation was performed by a modified QuEChERS method and the concentrations of mesotrione in maize and soil were determined by the liquid chromatography with tandem mass spectrometry (LC-MS/MS). The limit of detection was 0.0005mgkg(-1) and quantification 0.001mgkg(-1). The dissipation of mesotrione were described according to first-order (FO) kinetics equation with R(2) were between 0.8794 and 0.9934. The initial deposit of herbicide in soil and maize was higher in an acidic environment (0.06-0.18mgkg(-1)). A positive correlation between an alkaline pH and the rate of dissipation in soil was observed. The results showed that the time after which 50% (DT50) of substance has been degraded was different for both plant and soil. DT50 for soil was within the range 3.2-6.0days and 2.9-4.4days, for the maize 3.9-4.8days and 3.4-4.5days in an alkaline and an acidic environment, respectively. Concentration of mesotrione at applicable MRL level of 0.05mgkg(-1) in maize was achieved at 0.5-5.9days and at proposed MRL of 0.01mgkg(-1) at 8.8-15.8days. The results indicate that the application of mesotrione affected on DHA in the soil. One day after application this herbicide, concentration of DHA in soil was lower than in control plots, but after 21days was observed trend of increasing DHA.

Dissipation of six fungicides in greenhouse-grown tomatoes with processing and health risk.

Greenhouse studies were conducted to evaluate the dissipation rate kinetics and estimate the behavior of selected pesticides after washing, peeling, simmering, and canning of tomato expressed as processing factor (PF). Two varieties (Marissa and Harzfeuer) were treated by six fungicides: azoxystrobin, boscalid, chlorothalonil, cyprodinil, fludioxonil, and pyraclostrobin at single and double dose and risk assessment defined as hazard quotient was performed. The QuEChERS method was used for sample preparation followed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The dissipation of fungicides approximately fitted to a first-order kinetic model, with half-life values ranging from 2.49 and 2.67 days (cyprodinil) to 5.00 and 5.32 days (chlorothalonil) for Marissa and Harzfeuer variety, respectively. Results from processing studies showed that treatments have significant effects on the removal of the studied fungicides for both varieties. The PFs were generally less than 1 (between 0.01 and 0.90) and did not depend on variety. The dietary exposure assessed based on initial deposits of application at single and double dose on tomatoes and concentration after each process with PF correction showed no concern to consumer health. Our results would be a useful tool for monitoring of fungicides in tomatoes and provide more understanding of residue behavior and risk posed by these fungicides.

Rapid determination of acid herbicides in soil by liquid chromatography with tandem mass spectrometric detection based on dispersive solid phase extraction.

This study determined twenty six the highly sensitive phenoxy, pyridines, aliphatic and aromatic acid compounds in soil with a liquid chromatography tandem mass spectrometry. The samples were prepared by modified quick, easy, cheap, effective, rugged and safe (QuEChERS) analytical procedure in solid samples. Herbicides extraction effectiveness was evaluated at three different spiking levels (0.01, 0.1 and 1.0 mg kg(-1)). Fourteen different dispersive solid-phase extraction (d-SPE) sorbents in clean-up step were tested. The QuEChERS protocol with acidic alumina provided the highest number of pesticides with recoveries in the 70-120% range. The soil matrix effect was evaluated and for the majority of compounds were not significant, showing suppression or enhancement (±81-123%). The precision calculated as relative standard deviation (RSD) was below 22%. The linear relation was observed in the range 0.01-2.0 mg kg(-1) and the correlation coefficient R>0.999. The expanded measurement uncertainty was estimated as being on average, and was between 9% and 33%. The validated method was employed in the analysis of 309 real soil samples.

Multi-residue methods for the determination of over four hundred pesticides in solid and liquid high sucrose content matrices by tandem mass spectrometry coupled with gas and liquid chromatograph.

For the first time three methods: matrix solid phase dispersion (MSPD), original and modified QuEChERS, with and without clean up step were studied in order to evaluate the extraction efficiency of various classes of pesticides from solid and liquid high sucrose content matrices. Determinations over four hundred pesticides were performed by gas and liquid chromatography with triple quadrupole mass spectrometry (GC/LC/MS/MS) using multiple reaction monitoring. The proposed methods were validated on sugar beets and their technological product beet molasses. In general, the recoveries obtained for the original QuEChERS and MSPD method were lower (<70%) than for the modified QuEChERS without clean up in sugar beet and with clean up in beet molasses. Among these methods, high extraction yields were achieved as recommended in SANCO/12571/2013, with repeatability of 4.4-19.2% and within-laboratory reproducibility of 7.1-18.4% for citrate QuEChERS, whereas greater ruggedness were observed for MSPD. The limit of quantification (LOQ) at (the lowest MRL=0.01mgkg(-1)e.g. for oxamyl()) or below (0.005mgkg(-1)) the regulatory maximum residue level for the pesticides were achieved. The expanded measurement uncertainty was not higher than 30% for all target analytes. Matrix effects were compared and observed for both matrices at both gas and liquid chromatography. The most compounds showed signal enhancement and it was compensated by using matrix-matched calibration and modified QuEChERS characterized lower matrix effects. The confirmation of suitability citrate QuEChERS optimized method was to use for routine testing of several dozen samples determination and residue of epoxiconazole and tebuconazole (both at 0.01mgkg(-1)) in the samples of beet molasses and cyfluthrin (0.06mgkg(-1)) in sugar beet were found.

Removal of 16 pesticide residues from strawberries by washing with tap and ozone water, ultrasonic cleaning and boiling.

The effects of washing with tap and ozone water, ultrasonic cleaning and boiling on 16 pesticide (ten fungicides and six insecticides) residue levels in raw strawberries were investigated at different processing times (1, 2 and 5 min). An analysis of these pesticides was conducted using gas chromatography with nitrogen-phosphorous and electron capture detection (GC-NPD/ECD). The processing factor (PF) for each pesticide in each processing technique was determined. Washing with ozonated water was demonstrated to be more effective (reduction from 36.1 to 75.1 %) than washing with tap water (reduction from 19.8 to 68.1 %). Boiling decreased the residues of the most compounds, with reductions ranging from 42.8 to 92.9 %. Ultrasonic cleaning lowered residues for all analysed pesticides with removal of up to 91.2 %. The data indicated that ultrasonic cleaning and boiling were the most effective treatments for the reduction of 16 pesticide residues in raw strawberries, resulting in a lower health risk exposure. Calculated PFs for alpha-cypermethrin were used to perform an acute risk assessment of dietary exposure. To investigate the relationship between the levels of 16 pesticides in strawberry samples and their physicochemical properties, a principal component analysis (PCA) was performed. Graphical abstract ᅟ.

The evaluation of a fast and simple pesticide multiresidue method in various herbs by gas chromatography.

In this study two analytical methods, one based on matrix solid phase dispersion (MSPD) and the other on liquid-solid extraction (LSE), coupled with gas chromatography, were evaluated and used to determine the presence of 163 pesticides (6 acaricides, 62 fungicides, 18 herbicides and 77 insecticides) in various herbs. Both methods were optimized considering different parameters (sample to sorbent mass ratio, extracting solvent, sorbents for clean-up step, etc.). The results of these validated sample preparation procedures were compared. Under optimum conditions, the mean recoveries obtained were in the range of 70-119% for MSPD for most pesticides and 70-118% for LSE, but with several exceptions. Precision values, expressed as relative standard deviation (RSD), were ≤16% for MSPD and <18% for LSE. Correlation coefficients were higher than 0.99254 for both methods. LODs (limits of detection) and LOQs (limits of quantification) for MSPD were within the ranges of 0.003-0.03 and 0.005-0.04 mg/kg, respectively. The data demonstrate that the MSPD method was successfully used for the analysis of 163 pesticides in the following herbs: chamomile (Matricaria chamomilla L.), linden (Tilia), lungwort (Pulmonaria L.), melissa (Melissa L.), peppermint (Mentha piperita L.) and thyme (Thymus vulgaris L.). This paper indicates the potential of MSPD for qualitative and quantitative analysis of pesticide residues. This method was therefore validated at three spiking levels (the first ranging from 0.005 to 0.05 mg/kg, the second from 0.05 to 0.5 mg/kg and the third from 0.25 to 2.5 mg/kg) and applied to real samples (n = 15). MSPD proves to be a simple, fast and very useful multiresidue method and can be recommended for routine pesticide monitoring studies in various herbs.