Residual determination of pyrethrins in Lycium barbarum (goji) by GC-MS/MS and a dietary risk assessment of Chinese goji consumption

Translocation, subcellular distribution, and safety assessment of chlorfenapyr (CFP) and its metabolite tralopyril (TLP) in soil-cultivated cherry radish

Chlorfenapyr is a frequently used insecticide in vegetables, and understanding its translocation and distribution are important for determining the residues and dietary safety in these crops. In this paper, we studied the translocation, subcellular distribution, and dissipation of chlorfenapyr and tralopyril in soil-cultivated cherry radish. Both upward and downward translocations were observed for the analytes, although the extent was limited, as indicated by the bioconcentration and translocation factors (both <1). The analytes were primarily accumulated in the cell walls. Chlorfenapyr dissipated rapidly with half-lives of 5.90-7.10 d. Tralopyril can prolonged the dissipation rate of chlorfenapyr due to the total chlorfenapyr's half-lives of 7.20-9.46 d. The dietary risk for consumers can be neglected, when the sampling interval was 10 d. This study provided additional information on the translocation, distribution, and application method of chlorfenapyr in cherry radish and assessed the potential threats of chlorfenapyr to human health.

Study of dissipation dynamics and persistent toxicity of selected insecticides in chilli using LCMSMS

Chilli, a globally cultivated and consumed crop is significantly impacted by Thrips parvispinus. The reliance on pesticides could result in residue contamination, adversely affecting quality, leading to export rejections and health risks to consumers. This study evaluated the bioefficacy and persistent toxicity of fipronil and tolfenpyrad against thrips in chilli, and persistence of their residues. Tolfenpyrad demonstrated higher field efficacy (60.94 to 78.53%) against thrips compared to fipronil (37.61 to 58.07%). Residue analysis was performed in leaves and green chilli fruits using LC-MS/MS. Fipronil's efficacy decreased after 5 to 7 days of application, but both fipronil and tolfenpyrad residues remained for 20 and 30 days, respectively. In contrast, the residues in leaves caused persistent toxicity to thrips, causing about 50% mortality until 10 to 15 days in tolfenpyrad treatment. In green chilli, residues of tolfenpyrad and fipronil persisted for up to 40 and 25 days, necessitating pre-harvest intervals of 3.17 and 19.39 to 30.65 days, respectively, but with no dietary risk to consumers. Tolfenpyrad exhibited superior efficacy against T. parvispinus compared to fipronil, with a longer duration of effectiveness in leaves and quicker residue dissipation in chilli fruits and a short pre-harvest interval, supporting its use in Integrated Pest Management.

Pesticides in the environment: Degradation routes, pesticide transformation products and ecotoxicological considerations

Among rising environmental concerns, emerging contaminants constitute a variety of different chemicals and biological agents. The composition, residence time in environmental media, chemical interactions, and toxicity of emerging contaminants are not fully known, and hence, their regulation becomes problematic. Some of the important groups of emerging contaminants are pesticides and pesticide transformation products (PTPs), which present a considerable obstacle to maintaining and preserving ecosystem health. This review article aims to thoroughly comprehend the occurrence, fate, and ecotoxicological importance of pesticide transformation products (PTPs). The paper provides an overview of pesticides and PTPs as contaminants of emerging concern and discusses the modes of degradation of pesticides, their properties and associated risks. The degradation of pesticides, however, does not lead to complete destruction but can instead lead to the generation of PTPs. The review discusses the properties and toxicity of PTPs and presents the methods available for their detection. Moreover, the present study examines the existing regulatory framework and suggests the need for the development of new technologies for easy, routine detection of PTPs to regulate them effectively in the environment.

Insight into the uptake, translocation, metabolism, dissipation and risk assessment of tolfenpyrad in romaine and edible amaranth grown in hydroponic conditions

Tolfenpyrad is an alternative to highly water-soluble and ecotoxic insecticides that is widely used in China. It is absorbed and accumulates in vegetables, leading to potential public-health hazards. A systematic study of the fate of tolfenpyrad is necessary for proper application and food safety. Herein, we report on the uptake, translocation, metabolism, dissipation, and dietary risks of tolfenpyrad in hydroponic romaine and amaranth plants. Roots easily absorbed and accumulated tolfenpyrad, although transport was moderate in both vegetables. Basipetal translocation of tolfenpyrad occurred in romaine but not in edible amaranth, owing to differences in specific transport behaviour in each case. Six metabolites and three pathways were proposed. Tolfenpyrad affected antioxidant enzyme activities in different parts of the two vegetables. Tolfenpyrad dissipation proceeded swiftly, entailing an acceptable risk to humans. Our results provide information on the distribution and transport of tolfenpyrad, as well as on the safety in using it on vegetables.

Exploring thermal isomerisation in gas chromatography analyses using natural pyrethrins: Comparison of comprehensive two-dimensional and one-dimensional gas chromatography

This study aims to assess and qualitatively compare the visual presentation of chromatographic data from the isomerisation of natural pyrethrins - a group of pesticides derived from Chrysanthemum flowers - using one-dimensional gas chromatography (1DGC) and comprehensive two-dimensional gas chromatography (GC×GC). Molecular structural changes, such as thermal isomerisation in this case, occur during gas chromatography injection and separation, to provide characteristic patterns which may not be routinely recognised on the 1D chromatogram. To demonstrate the influence of analytical method parameters on isomerisation processes, variations in oven temperature (isothermal vs. temperature programmed analysis), inlet mode (split vs. splitless), inlet temperature, and carrier gas flow rate were investigated. Increasing oven temperature was the most significant factor affecting isomerisation. Splitless injection mode and increasing inlet temperature promoted isopyrethrin formation, while the effect of inlet temperature appeared minimal with a split injection technique, most likely due to the short residence time in the inlet. Increased carrier gas flow rates in a temperature programmed analysis reduced retention time and minimised isomerisation. The unique presentation of isopyrethrin peaks on a GC×GC contour plot allows for facile recognition of isomerisation especially at low concentrations, simplifies chromatogram interpretation, and aids in analyte identification. It also confirms that the isomerisation process is irreversible since the pyrethrin I and II compounds are absent throughout the bridge formation. These benefits support the use of GC×GC over 1DGC to study isomerisation. Additionally, due to limited data in the literature, Kováts retention indices and linear retention indices of the natural pyrethrins, including isopyrethrins, were experimentally determined on four columns: DB-5 ms UI, Rxi-17Sil MS, SLB-IL60i, and SLB-IL111i.

A novel sample preparation method based on polarity grouping for comprehensive determination of 315 pesticides and other contaminants in wolfberry by liquid chromatography-tandem mass spectrometry

A novel sample preparation method based on polarity grouping was developed for the comprehensive determination of 315 undesirable low-weight organic pollutants ranging from polar to weakly polar in wolfberry. The method involves the swelling of the sample in ammonium acetate buffer, two-phase extraction, three-phase extraction, and dispersive solid phase extraction (D-SPE) with the assistance of low-temperature centrifugation and analysis by ultrahigh performance liquid chromatography coupled with electrospray ionization tandem mass (UHPLC-ESI-MS-MS) by using the multiple reaction monitoring mode. The recoveries of the analytes with wide range of polarity were satisfactory. The matrix-fortified standard calibration curves were compared for quantification. The results of linearity were satisfactory with linear regression coefficients (R) ranging from 0.9901 to 1.000. The limits of quantification ranged from 1 μg/kg to 10.0 μg/kg, indicating the compliance of products with legal tolerances. The average recoveries for spiked wolfberry were in the range of 69.3 %-145.2 % with RSD values of 0.2 %-28.6 %. The inter-day precision was in the range of 0.2 %-27.0 %. For over 90 % of the analytes, the recoveries were 70 %-120 % with RSD values below 20 %. The application of this method in routine monitoring programs would imply a drastic reduction of both effort and time.

Ultra-high performance liquid chromatography and gas chromatography coupled to tandem mass spectrometry for the analysis of 32 pyrethroid pesticides in fruits and vegetables: A comparative study

In this study, multi-residue analysis methods for 32 pyrethroids in fruit and vegetable samples were established in both GC-MS/MS and UHPLC-MS/MS. The parameters that affecting the ionization efficiencies of pyrethroids in UHPLC-ESI-MS/MS, including ion source temperature, in-source fragmentation, and mobile phase conditions were thoroughly investigated to guarantee better performance. These two techniques were comprehensively compared in terms of recovery, LOQ, linearity, and matrix effects. In general, UHPLC-MS/MS was found suitable for more pesticides than GC-MS/MS. Lower LOQs were obtained for most of the selected pyrethroids in UHPLC-MS/MS. Similar results were obtained in terms of recoveries and RSDs for the validated pesticides in fortification experiments. A total of 136 real samples were analyzed by both techniques, obtaining similar results. The results suggest that UHPLC-MS/MS offers a suitable alternative to GC-MS/MS in the routine analysis of pyrethroids in fruits and vegetables.

Residue, dissipation and dietary intake risk assessment of tolfenpyrad in four leafy green vegetables under greenhouse conditions

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A QuEChERS-GC–MS/MS method was used to detect tolfenpyrad in leafy green vegetables.

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Half-lives of tolfenpyrad were 2.0–6.8 d in greenhouse-grown leafy green vegetables.

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PHI of tolfenpyrad was suggested as 21 d in BCL and 28 d in BBL, SOL and LSL.

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The potential health risk of tolfenpyrad was acceptable in leafy green vegetables.

A novel and accurate analytical method for the determination of tolfenpyrad in four leafy green vegetables, Brassica bara L., Spinacia oleracea L., Lactuca sativa L. and Brassica chinensis L., was developed and applied to investigate the residue distribution and dietary risk under greenhouse conditions. The established approach was determined to be adequate, with recoveries of 79.2%–92.9% and relative standard deviations < 8%. Tolfenpyrad dissipated relatively rapidly in four leafy green vegetables. Terminal residues of tolfenpyrad were below 0.5 mg/kg (maximum residue limit for Brassica bara L. set by China) in leafy green vegetables collected 28 d after the last application. Due to risk quotient values < 100%, the residue levels of tolfenpyrad in leafy green vegetables collected 21 days after the last application were deemed safe for consumers. The results provide field data for the reasonable use and dietary risk assessment of tolfenpyrad in leafy green vegetables.

Enantioselective evaluation of the chiral fungicide mandipropamid: Dissipation, distribution and potential dietary intake risk in tomato, cucumber, Chinese cabbage and cowpea

A chiral analytical method was developed and validated for the determination of mandipropamid enantiomers in tomato, cucumber, Chinese cabbage and cowpea. The linearity (R² > 0.99), accuracy (recovery: 73.8-106%) and precision (relative standard deviation: < 11%) were adequate for the detection of mandipropamid enantiomers in four vegetables. Field trials were further conducted to investigate the dissipation and residue distribution of mandipropamid and the possible enantioselectivity in different vegetables. Due to the shorter half-lives, mandipropamid dissipated more rapidly in Chinese cabbage (1.8-2.0 d) and cowpea (1.6-2.4 d) than in tomato (5.0-8.4 d) and cucumber (2.4-5.5 d). The residues of mandipropamid were 45-179 µg/kg in tomato 14 d at low dose, 48-98 µg/kg in cucumber 7 d after spraying twice at low dose, and < 2.5-1942 µg/kg in Chinese cabbage and cowpea in all treatments, which were below the maximum residue limits of mandipropamid set by the European Union and Codex Alimentarius Commission. Enantioselectivity was observed during the mandipropamid dissipation process in four vegetables. The S-(+)-enantiomer dissipated more rapidly than the R-(-)-enantiomer in tomato and Chinese cabbage (enantiomeric fractions > 0.5). For cucumber and cowpea, the dissipation of the R-enantiomer was preferential (enantiomeric fractions < 0.5). According to the risk quotient data (<< 100%), the residues of mandipropamid in four vegetables were safe for Chinese consumers. This study could provide useful information for the dissipation fate and residue distribution of mandipropamid in vegetables at the enantiomer level and offer some guidance for the dietary intake risk evaluation of mandipropamid in vegetables.

Health Benefits and Applications of Goji Berries in Functional Food Products Development: A Review

Goji berries have long been used for their nutritional value and medicinal purposes in Asian countries. In the last two decades, goji berries have become popular around the world and are consumed as a functional food due to wide-range bioactive compounds with health-promoting properties. In addition, they are gaining increased research attention as a source of functional ingredients with potential industrial applications. This review focuses on the antioxidant properties of goji berries, scientific evidence on their health effects based on human interventional studies, safety concerns, goji berry processing technologies, and applications of goji berry-based ingredients in developing functional food products.

Comprehensive Strategy for Sample Preparation for the Analysis of Food Contaminants and Residues by GC-MS/MS: A Review of Recent Research Trends

Food safety and quality have been gaining increasing attention in recent years. Gas chromatography coupled to tandem mass spectrometry (GC-MS/MS), a highly sensitive technique, is gradually being preferred to GC-MS in food safety laboratories since it provides a greater degree of separation on contaminants. In the analysis of food contaminants, sample preparation steps are crucial. The extraction of multiple target analytes simultaneously has become a new trend. Thus, multi-residue analytical methods, such as QuEChERs and adsorption extraction, are fast, simple, cheap, effective, robust, and safe. The number of microorganic contaminants has been increasing worldwide in recent years and are considered contaminants of emerging concern. High separation in MS/MS might be, in certain cases, favored to sample preparation selectivity. The ideal sample extraction procedure and purification method should take into account the contaminants of interest. Moreover, these methods should cooperate with high-resolution MS, and other sensitive full scan MSs that can produce a more comprehensive detection of contaminants in foods. In this review, we discuss the most recent trends in preparation methods for highly effective detection and analysis of food contaminants, which can be considered tools in the control of food quality and safety.

Stereoselective degradation behavior of the novel chiral antifungal agrochemical penthiopyrad in soil

Penthiopyrad is a chiral carboxamide fungicide with a broad spectrum of fungicidal activity. However, there is no report on the analysis of the enantiomers of penthiopyrad and their environmental behavior. Soil is an important carrier for pesticides to affect the environment. Therefore, this study aimed to investigate the absolute configuration, stereoselective degradation, configuration stability and potential metabolites of this agrochemical in soil under different laboratory conditions. R-(-)-penthiopyrad and S-(+)-penthiopyrad were identified by the electronic circular dichroism method. Regarding the racemic analyte, the degradation half-lives of the stereoisomers ranged from 38.9 to 97.6 days, the S-(+)-stereoisomer degraded preferentially in four types of Chinese soil. However, enantiopure R-(-)-penthiopyrad degraded faster than its antipode, a finding that might be related to the microbial activity in soil. The organic matter (OM) content influenced the stereoselective degradation of rac-penthiopyrad. No configuration conversion was observed in both enantiopure analyte degradation processes. One possible metabolite, 753-A-OH, was detected in the treated soil samples, and the degradation pathway might be a hydroxylation reaction. This is the first report of the absolute configuration of penthiopyrad stereoisomers and the first comprehensive evaluation of the stereoselective degradation of penthiopyrad in Chinese soil. Stereoselective degradation of rac-penthiopyrad was observed in the four types of soil. And the stereoselectivity might be inhibited by OM. This study provides more accurate data to investigate the environmental behavior of penthiopyrad at the stereoisomer level.