The fate of spirotetramat and its metabolite spirotetramat-enol in apple samples during apple cider processing

Distribution, variability, and dietary risk assessment of etoxazole residues in apples and apple juice

Etoxazole, while preventing pest mites on apple trees, leaves some residues in the produce, triggering consumer concerns. Here, the study investigated the distribution of etoxazole in apples after application and the change pattern of residue during apple juice processing. An analytical method for the determination of etoxazole was established to meet the requirements of residue analysis, with accuracy ranging from 80 to 95% and precision from 1.3 to 7.8% and linearity with R2 > 0.9975. Changes in residue levels of etoxazole in apples were tested in 12 regions of China, and the results indicated that the residues in apples gradually decreased, with a dissipation half-life of 8.0-12.6 days. The final residues in apples harvested 28 and 35 days after application were below 0.08 mg/kg, which was below the maximum residue limits (0.1 mg/kg). The percentages of etoxazole in pulp, core, and peel were 45%, 37%, and 18%, respectively, whereas the pesticide was mainly enriched in the pomace after juicing. During apple juice processing, the best pesticide removal was achieved by juicing, with a removal rate of 72% and a processing factor of 0.11. After a series of apple juice processing steps, the residual pesticides were effectively removed with a total processing factor of 0.04. The dietary exposure risk index for etoxazole in apples harvested after 28 days was below 100%, indicating an acceptable risk level, with the highest risk index observed in young children. Moreover, the introduction of processing actions reduced the risk of dietary exposure to pesticides in processed products.

Insights on Degradation, Processing Factors, and Risk Assessment of Pesticide Pymetrozine, Spirotetramat, and Its Four Metabolites on Goji Berry: "Third Pole" Medicine and Food Homologous Crop

Pesticides are widely used in agriculture, and agricultural commodities are generally consumed as processed foods. How effective these processing procedures are at removing pesticide residues is not well understood. We report initial concentrations of one pesticide that is used extensively on crops of Goji berries, spirotetramat (and its four metabolites: spirotetramat-enol, spirotetramat-enol-glucoside, spirotetramat-monohydroxy, and spirotetramat-keto-hydroxy), and pymetrozine, to be 231.31, 297.42, 229.15, 252.33, 292.73, and 83.18 μg kg-1, respectively. Only 0.18-3.18% of pesticides were eliminated from produce by maceration and washing. Pesticide reduction during processing was 21.23-58.72% (traditional methods), 33.86-73.66% (by cooking samples), and 71.24-90.23% (through vinification), with corresponding processing factors (PFs), a measure of how processing technique affects pesticide residue levels, 0.111-0.771, 0.016-2.33, and 0.008-43.1. For traditional methods, in particular, the PFs of pesticides were 1.77-43.1, suggesting that considerable pesticide enrichment occurred. Combined with the field trial and PF residue data, the acute and chronic dietary risks of pesticides using these processing methods ranged 0.031-1.83 and 0.002-2.51%, respectively. This study provides basic information that can be used to evaluate the potential risks to health of exposure to pesticide residues.

Residual behaviors and health risk assessment of dinotefuran, flonicamid, and their metabolites during apple growth, storage, and processing

Understanding the fate of dinotefuran, flonicamid, and their metabolites is crucial for accurate dietary exposure assessment and human health. The dissipation and removal of dinotefuran, flonicamid, and their metabolites from apple cultivation to consumer's plate were studied. The results of field and storage experiments indicated significant differences in half-life at different doses. And the half-life was shorter in the field than that in storage. During washing, the residues of all target compounds were decreased. Among washing solutions, the PF values of each pesticide gradually decreased with the increasing washing time and washing solution concentration. 2 % NaHCO3 produced best removal effect after washing 15 min. Various food processing techniques, including peeling, fermentation, clarification, blanching, drying, enzymolysis, and simmering, were used to confirm the most effective way to remove these target compounds. For majority processes, the PF values were < 1, and the peeling and fermentation could obviously reduce pesticide residues. The risk quotients were < 100 %, implying that the risks were acceptable. This study provided a necessary information for the use of pesticides in apple cultivation and improvement of processing technology to ensure food safety.

Dissipation behavior and risk assessment of imidacloprid and its metabolites in apple from field to products

Pesticides play vital roles in controlling pests and boosting crop yields. Imidacloprid is widely used all over the world and may form in agricultural products. The presence of pesticide residues in apples raises serious health concerns. Understanding the residual fate of imidacloprid is critical for food safety and human health. In this study, the dissipation behavior, metabolism, household processing and risk assessment of imidacloprid and its metabolites in apple were investigated from filed to products. Field experiment results suggested that the half-lives of imidacloprid at 5 times the recommended dosage was 1.5 times that of the standard dosage. And the final residues of imidacloprid were less than the established maximum residue limits (MRLs). Clarification and simmering had little effect on the reduction the residues of imidacloprid and its metabolites. The calculated processing factors were lower than 1 for imidacloprid and its metabolites, implying that the residual ratios of imidacloprid and its metabolites in each steps of the food processing were reduced. The risk quotients were <1 for all Chinese people, indicating that acceptable risks associated with dietary exposure to imidacloprid in apple. However, the higher risks were observed in young people than adults, and females faced higher risks than males. Given high residue levels in pomace, imidacloprid and its metabolites should be further studied in commercial byproducts.

Residual estimation of spirotetramat and its metabolites in chilli and soil by LC-MS/MS

Two applications of spirotetramat were done to study the dissipation and persistence of spirotetramat and its four different metabolites in chilli and soil at 10 days interval. Total spirotetramat residues were estimated by LC-MS/MS instrument. The mean initial deposits of total spirotetramat after application of spirotetramat 15.31 OD @ 60 (X dose), 75 (1.25 × dose) and 120 (2 × dose) g a.i. ha-1 on green chilli were found to vary from 0.38 to 0.83 mg kg-1 during the initial year. Spirotetramat and its metabolite residues in green chilli were found to be below limit of quantification (0.01 mg kg-1) after 15 days of application. The spirotetramat cis enol (the major metabolite) was formed in both the soil and the plant. The residues of spirotetramat-monohydroxy were below LOQ irrespective of any substrate during the estimation. In soil, the total initial spirotetramat deposits for the 1st year were found 0.09 for X dose, 0.12 for 1.25 × dose and 0.20 mg kg-1 for 2 × dose. After 3 days for both X and 1.25 × doses and 5 days for 2 × dose, the total spirotetramat residues were below LOQ. The spirotetramat's half-life values have been determined to be between 3.19 and 3.93 days and 1.00 and 1.59 days, respectively, in soil and green chilli fruits. One day waiting period is proposed for the safe consumption of green chilli when the spirotetramat was applied irrespective of the dose.

Dissipation, residues, and evaluation of processing factor for spirotetramat and its formed metabolites during kiwifruit growing, storing, and processing

Spirotetramat is widely used around the world to control sucking pests and may form in agricultural products. In the current study, the dissipation, residues, and evaluation of processing factor (PF) for spirotetramat and its formed metabolites were investigated during kiwifruit growing, storing, and processing. The residue analysis method was established based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) combined with a QuEChERS method to detect the residues of spirotetramat and its metabolites in kiwifruit and its processed products. The method provided recoveries of 74.7-108.7%, and the relative standard deviations (RSDs) were 0.6-13.1%. The LOQs of spirotetramat and its four metabolites were 1 μg kg-1. The degradation of spirotetramat was best fitted for the first-order kinetics model with a half-life of 9.90-10.34 days in the field and 24.75-30.13 days during storage. Residues of spirotetramat and its formed metabolites in kiwifruit would not pose dietary risk to consumers. Moreover, the peeling and fermentation were the highest removal efficiency for the spirotetramat and its formed metabolite residues during processing. The PF values calculated after each individual process were < 1, indicating a significant reduction of residues in different processing processes of kiwifruit. The spirotetramat was degraded during kiwifruit wine-making process with half-lives of 3.36-4.91 days. B-enol and B-keto were the main metabolites detected in kiwifruit and its processed products. This study revealed the residues of spirotetramat and its formed metabolites in kiwifruit growing, storing, and processing, which helps provide reasonable data for studying the dietary risk factors of kiwifruits and products.

The Residue and Dietary Risk Assessment of Spirotetramat and Its Four Metabolites in Cabbage Using Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Spirotetramat is a potential tetronic acid pesticide for controlling various pests with piercing-sucking mouthparts. To clarify its dietary risk on cabbage, we established an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method and then investigated the residual levels of spirotetramat and its four metabolites in cabbage collected from field experiments under good agricultural practices (GAPs). The average recoveries of spirotetramat and its metabolites in cabbage were 74~110%, while the relative standard deviation (RSD) was 1~6%, and the limit of quantitation (LOQ) was 0.01 mg kg^-1. The terminal residue of spirotetramat was in the range of <0.05~0.33 mg kg^-1, the chronic dietary risk (RQ_c) was 17.56%, and the acute dietary risk (RQ_a) was 0.025~0.049%, which means an acceptable dietary intake risk. This study provides data to guide on the use of spirotetramat and to establish the maximum residue limits (MRLs) of spirotetramat on cabbage.

Dissipation kinetics and exposure of spirotetramat and pymetrozine in open fields, a prelude to risk assessment of green bean consumption

Determination and dissipation kinetics of pymetrozine and spirotetramat in green bean were studied using a QuEChERS method coupled to high-performance liquid chromatography-tandem mass spectrometry. Pymetrozine recoveries ranged between 88.4-93.7%, with relative standard deviation (RSD) of 5.5-14.4%. For spirotetramat the recoveries ranged between 91.7-103.4%, and the RSD were in the range of 3.2 to 12.4%. The limits of quantification (LOQs) were 0.01 mg/kg and 0.005 mg/kg for pymetrozine and spirotetramat, respectively.The developed analytical method was used to study the degradation rates of pymetrozine and spirotetramat in green bean grown in open field. Results showed that pymetrozine and spirotetramat followed the first-order kinetics model with half-lives of 3.3 days and 4.2 days, respectively. Furthermore, risk assessment was carried out which showed that, the chronic risk quotient (RQc) values for pymetrozine and spirotetramat were much lower than 100%. The present results indicated that the health risks posed for consumers by the pymetrozine and spirotetramat residues were negligible at the recommended dosages.

High and low temperature processing: Effective tool reducing pesticides in/on apple used in a risk assessment of dietary intake protocol

Apples play an important role in everyone's diet and may contain pesticide residues that can pose a significant health problem for consumers. Various technological processes are promising methods for minimizing pesticide concentrations in fruit. Therefore, the subject of this comprehensive study was to investigate the effects of high-temperature (baking) and low-temperature (freeze-drying) processes on the change in the levels of nine fungicides in apples with skin and peeled. The investigated compounds belong to the chemical groups of benzimidazole (thiophanate methyl and carbendazim), phtalimide (captan and their metabolite tetrahydrophtalimid (THPI)), strobilurin (pyraclostrobin, trifloxystrobin) and triazole (difenoconazole, tebuconazole, tetraconazole). Processing factors (PF) were calculated for each pesticide-process-product combination. The results show that baking and freeze-drying generally reduced pesticide concentrations, with PFs ranging from 0.31 to 0.81 and 0.26 to 0.68, respectively. Apart from freeze-drying for carbendazim and baking for captan, PFs were above 1. Only for thiophanate-methyl, a complete reduction was observed, which resulted from complete degradation to carbendazim. The study also aimed to assess human risk according to the new strategy for different sub-populations with conversion using the 36 PFs obtained. The highest acute exposure (expressed as %ARfD) was obtained for tebuconazole in raw apples (initial concentration of 1.42 mg/kg; 400% ARfD) for Dutch toddlers. After food processing, this decreased to 284% (0.74 mg/kg, baking) and to 137% (0.37 mg/kg, freeze-drying), but was still above the safety limit. Similarly, for adults and the general French population for tebuconazole, the %ARfD was high as it reached the values of 104% (initial concentration of 0.89 mg/kg) in unprocessed apples, 73.9% after baking (0.73 mg/kg) and 35.6% after freeze-drying (0.35 mg/kg). The results indicate that food processing techniques can potentially be used to minimize the hazardous effects of pesticide residues on human health.

Dissipation characteristics of spirotetramat and its metabolites in two phenotypically different Korean vegetables under greenhouse conditions

This study involved analysis and method validation of spirotetramat applied to two phenotypically different Korean vegetables (e.g. Korean cabbage and shallots) to determine the safe pre-harvest residue limit (PHRL) and comparative dissipation patterns. Two steps of the investigation involved greenhouse monitoring during crop cultivation followed by LC-MS/MS analysis. Commercial spirotetramat was sprayed twice with seven-day intervals according to the spray schedule (0, 3, 7, 10, 14, and 21 days before harvest) at the dose recommended by the Ministry of Food and Drug Safety (MFDS), Korea. During the validation of the analytical method, good linearity, specificity, and acceptable recoveries (82%-114% for Korean cabbage and 82%-111% for shallot) were established for spirotetramat and its four metabolites. The calculated biological half-life derived from the first-order reaction (t_1/2) of spirotetramat was 4.8 days for Korean cabbage and 4.0 days for shallot, respectively. The safe PHRL for Korean cabbage was suggested at 7 days, due to permissible spirotetramat concentration in terms of an acceptable MRL. The findings of the study will be used as the analytical reference point for developing spirotetramat safety guidelines for use in the vegetables investigated.

Determination, residue analysis and risk assessment of thiacloprid and spirotetramat in cowpeas under field conditions

The dissipation and residue levels of thiacloprid, spirotetramat and its four metabolites residues in cowpeas were investigated under field conditions. The QuEChERS technique with high-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) was used to detect thiacloprid, spirotetramat and its four metabolites residues content in cowpeas. The recoveries were 81.3–95.1% at a spike level of 0.005–0.5 mg/kg, the relative standard deviations (RSDs) were 2.1–9.5%. The dissipation kinetics data showed that thiacloprid and spirotetramat in cowpeas were degraded with the half-lives of 1.14–1.54 days and 1.25–2.79 days. The terminal residues of thiacloprid and spirotetramat were 0.0255–0.4570 mg kg⁻¹ and 0.0314–0.3070 mg kg⁻¹ after application 2 times with a pre-harvest interval (PHI) of 3 days under the designed dosages. The chronic and acute dietary exposure assessment risk quotient (RQ) values of thiacloprid in cowpeas for different consumers were 2.44–4.41% and 8.72–15.78%, respectively, and those of spirotetramat were 1.03–1.87% and 0.18–0.32%, respectively, all of the RQ values were lower than 100%. The dietary risk of thiacloprid through cowpeas to consumers was higher than spirotetramat. The results from this study are important reference for Chinese governments to develop criteria for the safe and rational use of thiacloprid and spirotetramat, setting maximum residue levels (MRLs), monitoring the quality safety of agricultural products and protecting consumer health.

The processing factors of canning and pasteurization for the most frequently occurring fungicides and insecticides in apples and their application into dietary risk assessment

The challenge of the present comprehensive work was to study, from apple orchards to consumer's plate, the influence of high- and low-temperature thermal treatments on the most frequently occurring fungicides (boscalid, captan, pyraclostrobin) and insecticides (acetamiprid, methoxyfenozide) in apples and processing factor (PF) application for more realistic dietary risk assessment in the new EFSA methodology. Dry pasteurization and canning combined with previous preliminary treatment gave PFs = 0.25-1.8 of the five active substances. Acute exposure (expressed as %ARfD) in the raw commodity was demonstrated to be 168.1% for acetamiprid in the worst case (input - highest residue) and 307.9% for boscalid in the most critical case (input - MRL), and after re-calculation for PF, decreased to 139.5% for acetamiprid in canned product and 203.2% for boscalid in pasteurized apples. These novel data may be helpful in estimating new threshold residue levels significant in food safety especially intended for children.

Determination of etoxazole in different parts of citrus fruit and its potential dietary exposure risk assessment

In this study, the profile of etoxazole in whole citrus, peel and pulp samples collected from Chongqing, Guangdong and Anhui provinces was monitored and their dietary risk to human had also been assessed. The final residual levels and distributions of etoxazole in citrus samples were detected by using an ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The results showed that final concentrations of etoxazole in whole citrus, peel, and pulp were ranged at 0.012-0.174, 0.010-0.637, and 0.010-0.011 mg kg^-1, respectively. The assessment of dietary risk suggested that chronic dietary risk of etoxazole in whole fruit and peel were 0.010-0.197% and 0.035-0.951%, respectively. Our findings indicated that the chronic risk of daily consumption of citrus fruit is acceptable at recommended dosage.

Enantioselective fate of famoxadone during processing of apple cider and grape wine

Famoxadone enantiomers were separated on Lux Amylose-1 chiral column and determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The half-lives of R-(-)-famoxadone and S-(+)-famoxadone were 69.3 and 86.6 h in apple cider, 231.0 and 346.5 h in apple pomace, 69.3 and 77.0 h in grape wine, and 231.0 and 346.5 h in grape pomace, respectively. The enantiomeric fraction (EF) values decreased gradually from 0.498, 0.499, and 0.500 (0 h) to 0.404, 0.374, and 0.427 (144 h) and then increased gradually to 0.474, 0.427, and 0.422 (312 h) in apple cider, grape wine, and grape pomace. The EF value in apple pomace decreased gradually from 0.499 (0 h) to 0.450 (168 h) and then increased gradually to 0.482 (312 h). The processing factors (PFs) for famoxadone ranged from 0.014 to 0.024 in the overall process. The residue of famoxadone reduced 94.7-97.4% after the fermentation process.

Enantioselective fate of mandipropamid in grape and during processing of grape wine

Enantioselective monitoring of chiral fungicide mandipropamid enantiomers were carried out in grapes and wine-making process. The enantiomers of mandipropamid were separated on a Lux Cellulose-2 column and determined by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The processing procedure included washing, fermentation, and clarification. Significant enantioselectivity was observed in grape under field conditions and during wine-making processing. The half-lives of R-mandipropamid and S-mandipropamid were 5.63 days and 7.79 days under field conditions 43.3 h and 69.3 h during wine-making processing, respectively. The EF values ranged from 0.498 to 0.283 in grape under field conditions, and the EF values were from 0.458 (0 h) to 0.362 (312 h) during the whole fermentation process. The results indicated that R-mandipropamid degraded faster than S-mandipropamid in grape under field conditions and during the fermentation process. The processing factors (PFs) were less than 1 for each procedure, and the PF ranged from 0.005 to 0.025 in the overall process, which indicated that the wine-making process can reduce mandipropamid residue in grape wine. The results of this study could help facilitate more accurate risk assessments of mandipropamid in table grapes and during wine-making process.

The Dissipation of Cyazofamid and Its Main Metabolite CCIM During Wine-Making Process

Few studies have focused on the residues of cyazofamid and its main metabolite CCIM (4-chloro-5-p-tolylimidazole-2-carbonitrile) in the wine making process, which is crucial to evaluate the potential food risk of cyazofamid and CCIM. In this work, detailed study has been conducted on the evaluation of the fate of cyazofamid and its main metabolite CCIM during the wine-making process. The targeted compounds cyazofamid and CCIM were separated and determined by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) and processing procedure including washing, peeling, fermentation, and clarification. Results showed that residues of cyazofamid and CCIM decreased significantly in wine processing. The dissipation of cyazofamid in the fermentation process followed the first-order of kinetics, and the half-life of cyazofamid was 46.2-63.0 h, whereas, the residues of CCIM, in the three treatments, decreased with time elapse. The processing factors (PFs) were all less than one in different processing processes, and the PFs ranges of cyazofamid and CCIM were 0.003-0.025 and 0.039-0.067 in three treatments in the overall process. The outcome indicated that the whole process could significantly reduce the residues of cyazofamid and CCIM in red and white wines. The results might provide more precise risk assessments of cyazofamid in the wine-making process.

Determination of 107 Pesticide Residues in Wolfberry with Acetate-buffered Salt Extraction and Sin-QuEChERS Nano Column Purification Coupled with Ultra Performance Liquid Chromatography Tandem Mass Spectrometry

A multi-residue method for the determination of 107 pesticide residues in wolfberry has been developed and validated. Similar pretreatment approaches were compared, and the linearity, matrix effect, analysis limits, precision, stability and accuracy were validated, which verifies the satisfactory performance of this new method. The LODs and LOQs were in the range of 0.14–1.91 µg/kg and 0.46–6.37 µg/kg, respectively. The recovery of analytes at three fortification levels (10 µg/kg, 50 µg/kg, 100 µg/kg) ranged from 63.3–123.0%, 72.0–118.6% and 67.0–118.3%, respectively, with relative standard deviations (RSDs) below 15.0%. The proposed method was applied to the analysis of fifty wolfberry samples collected from supermarkets, pharmacies and farmers’ markets in different cities of Shandong Province. One hundred percent of the samples analyzed included at least one pesticide, and a total of 26 pesticide residues was detected in fifty samples, which mainly were insecticides and bactericide. Several pesticides with higher detection rates were 96% for acetamiprid, 82% for imidacloprid, 54% for thiophanate-methyl, 50% for blasticidin-S, 42% for carbendazim, 42% for tebuconazole and 36% for difenoconazole in wolfberry samples. This study proved the adaptability of the developed method to the detection of multiple pesticide residues in wolfberry and provided basis for the research on the risks to wolfberry health.

The dissipation of cyazofamid and its main metabolite CCIM during tomato growth and tomato paste making process

In several studies focused on the residues of cyazofamid and its main metabolite 4-chloro-5-p-tolylimidazole-2-carbonitrile (CCIM) on tomato where it is widely used, CCIM has been shown to have higher acute toxicity than cyazofamid, and this is crucial to evaluate the potential food risk of cyazofamid and CCIM. In this study, the dissipation of cyazofamid and CCIM during tomato growth and tomato paste making process were assessed. The targeted compounds cyazofamid and CCIM were determined by LC-MS/MS. The results indicated that the half-life of cyazofamid was 4.6 days after applying in the field, and the maximum value of CCIM was 0.08 mg/kg at 3 days after the last application of cyazofamid, then gradually decreased. In addition, the concentrations of cyazofamid and CCIM were affected by different processing steps including washing, peeling, homogenisation, simmering, and sterilisation. Results showed that the mean losses of cyazofamid and CCIM were 92.3% and 75.2% after washing and peeling. The Processing Factor (PF) values were all less than 1. Especially for peeling, the PFs of cyazofamid and CCIM were 0.12 and 0.04, respectively.

Environmental behaviors of spirotetramat in water

Spirotetramat is a pesticide with bidirectional systemicity in both xylem and phloem. Currently, researches show that spirotetramat has definite toxicity to aquatic organism. This paper aims to study the environmental behaviors of spirotetramat in water, in the hope of providing guidance for security evaluation of spirotetramat. The researches in this paper showed that under lighting condition, the half-life period of spirotetramat in water was 13.59 days. In water, spirotetramat could be degraded into B-enol and B-keto. As seen from the residual concentrations of two products, B-enol was the dominant degradation product. Under different temperatures, the hydrolysis products of spirotetramat remain B-enol and B-keto. The temperature has little effect on the residual concentration of spirotetramat in water. The residual concentration of B-enol in water gradually increased with the extension of time but B-keto had no significant change. In the buffer solution of different pH values, the degradation rate of spirotetramat was significantly enhanced with the increase of solution pH value. The hydrolysis products of spirotetramat in buffer solution of different pH values were still B-enol and B-keto, and pH exerted certain influence on the residual concentration of B-enol in water. The hydrolysis conversion of spirotetramat has theoretical and practical significance for the safe and reasonable usage of it, as well as for the further evaluation of spirotetramat's ecological risk in water.

Residue and Dietary Risk Assessment of Chiral Cyflumetofen in Apple

Ultra-performance convergence chromatography is an environmentally-friendly analytical method that uses dramatically reduced amounts of organic solvents. In addition, a robust and highly sensitive chiral separation method was developed for the novel chiral acaricide cyflumetofen by using ultra-performance convergence chromatography coupled with tandem mass spectrometry, which shows that stereoisomer recoveries determined for various apple parts ranged from 78.3% to 119.9%, with the relative standard deviations being lower than 14.0%. The half-lives of (−)-cyflumetofen and (+)-cyflumetofen obtained under 5-fold applied dosage equal to 22.13 and 22.23 days, respectively. For 1.5-fold applied dosage, the respective values were determined as 22.42 and 23.64 days, i.e., the degradation of (−)-cyflumetofen was insignificantly favored over that of its enantiomer. Importantly, cyflumetofen was unevenly distributed in apples, with its relative contents in apple peel, peduncle, and pomace equal to 50%, 22%, and 16%, respectively. The proposed method can be used to efficiently separate and quantify chiral pesticide with advantages of a shorter analysis time, greater sensitivity, and better environmental compatibility. Additionally, the consumption of apples with residue of cyflumetofen did not pose a health risk to the population if the cyflumetofen applied under satisfactory agricultural practices after the long-term dietary risk assessment.

The fate of spirotetramat and dissipation metabolites in Apiaceae and Brassicaceae leaf-root and soil system under greenhouse conditions estimated by modified QuEChERS/LC-MS/MS

The aim of this study was to investigate the dissipation of spirotetramat and its four metabolites (B-enol, B-keto, B-mono and B-glu) in different parts of vegetables belong to the minor crops (Appiacea and Brassicaceae) and soil from cultivation. The challenge of this study was to apply an optimized clean up step in QuEChERS to obtain one universal sorbent for different complex matrices like leaves with high levels of pigments, roots containing acids, sugars, polyphenolls and pigments and soil with organic ingredients. Eight commercial (Florisil, neutral alumina, GCB, PSA, C18, diatomaceous earth, VERDE and ChloroFiltr) and one organic (Chitosan) sorbents were tested. A modified clean up step in QuEChERS methodology was used for analysis. The dissipation of spirotetramat and its metabolites was described according to a first-order (FO) kinetics equation with R² between 0.9055 and 0.9838. The results showed that the time after 50% (DT₅₀) of the substance degraded was different for soil, roots and leaves, and amounted to 0.2day, 2.8-2.9days and 2.1-2.4days, respectively. The terminal residues of spiroteramat (expressed as the sum of spirotetramat, B-enol, B-glu, B-keto and B-mono) were much lower than the MRLs.

Simultaneous determination of 124 pesticide residues in Chinese liquor and liquor-making raw materials (sorghum and rice hull) by rapid Multi-plug Filtration Cleanup and gas chromatography-tandem mass spectrometry

A multi-residue method was developed for the determination of 124 pesticide residues in Chinese liquor and liquor-making raw materials (sorghum and rice hull) by rapid Multi-plug Filtration Cleanup (m-PFC) and GC-MS/MS detection. Different combination and proportion sets of sorbents were initially optimized for each matrix with adispersive solid-phase extraction (d-SPE) procedure. Satisfactory linearity was obtained for the 124 pesticides with regression coefficients (R²) greater than 0.9901. Mean recoveries of 121 pesticides were in the range of 71-121% with Relative Standard Deviations (RSDs) lower than 16.8% except cyprodinil, diflufenican and prothioconazole. The Limit of Quantification (LOQs) was in the range of 1.0×10^-4-5.0×10^-3mgkg^-1 and the Limit of Detection (LODs) ranged from 3.0×10^-5 to 1.5×10^-3mgkg^-1 for the 124 pesticides in the matrices. It is demonstrated the m-PFC procedure is superior to the d-SPE method and it could be used to routinely monitor of pesticide residues in market samples.

Behaviour of spirotetramat residues and its four metabolites in citrus marmalade during home processing

The effect of home processing on the residues of spirotetramat and its four metabolites (B-enol, B-glu, B-mono and B-keto) in citrus marmalade is comprehensively investigated in this paper by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). A five-fold recommended dose of spirotetramat was applied to citrus fruit under field conditions and the processing included five steps: washing, peeling, pre-treatment for peel, mixing and boiling. The results showed that spirotetramat was the predominant component detected in unprocessed citrus, accounting for 64%. All the detected residues were primarily deposited on citrus peel, except for B-enol which was also present in the citrus pulp. Washing reduced spirotetramat, B-enol, B-glu and B-keto by 83%, 56%, 41% and 16%, respectively, and pre-treatment of the peel removed between 42% and 68% of the residues. Four compounds were all below the limit of detection after the mixing step. In the final product, only B-keto was detected at the concentration of 0.010 mg kg(-1). After the whole process, the processing factors for spirotetramat, B-enol, B-glu and B-keto were < 0.041, < 0.125, < 0.294 and 0.313, respectively, which indicated that home processing can significantly reduce residues of spirotetramat and its metabolites in citrus marmalade.

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.

Residue behaviour of six pesticides in button crimini during home canning

The effect of home canning (including washing, boiling, cooling, adding solution and sterilisation) on residue levels of imidacloprid, diflubenzuron, abamectin, pyriproxyfen and β-cypermethrin and chlorothalonilin on button crimini was assessed. Residues of imidacloprid, diflubenzuron, abamectin and pyriproxyfen were measured by UPLC-MS/MS; the residues of β-cypermethrin and chlorothalonil were measured by GC. Results showed that washing resulted in a 3.8% reduction of the initial residue level of imidacloprid (p ≤ 0.05). From washing to sterilisation the processing effect was significant compared with raw crimini (p ≤ 0.05), but processing through cooling and adding solution had no effect. For diflubenzuron, from raw crimini to sterilisation the processing effect was significant by comparison with the initial level (p ≤ 0.05); the processing effect was not obvious between two sequential steps, and the sequential steps have list: washing and boiling, boiling and cooling, boiling and adding of solution, cooling and adding solution. The changes in abamectin levels were also significant from raw crimini to sterilisation compared with raw crimini (p ≤ 0.05), but the changes were not obvious from boiling to adding solution and amongst them. For pyriproxyfen, washing resulted in a 39% reduction, but changes were not obvious from washing to sterilisation, p ≤ 0.05 between two consecutive steps. The whole procedure could significantly decrease residues of β-cypermethrin (p ≤ 0.05); washing could significantly reduce residues of β-cypermethrin; the effects of last procedures were complicated, and p ≤ 0.05 between two consecutive steps. Washing resulted in an 80% reduction of chlorothalonil; after washing there were no detectable residues. After the whole process, the processing factors for imidacloprid, diflubenzuron, abamectin, pyriproxyfen, β-cypermethrin and chlorothalonil were 0.40, 0.22, 0.04, 0.85, 0.28 and 0, respectively.