QuEChERS multiresidue method validation and mass spectrometric assessment for the novel anthranilic diamide insecticides chlorantraniliprole and cyantraniliprole

Method validation, residue behaviour and dietary risk assessment of insecticides (cyantraniliprole, acetamiprid, flubendiamide and its metabolite, des-iodo flubendiamide) in or on broccoli using LC-MS/MS

Residue behaviour and dietary risk assessment of cyantraniliprole, flubendiamide and acetamiprid in broccoli were carried out using the QuEChERS (quick, easy, cheap, effective, rugged and safe) technique coupled with LC-MS/MS. The QuEChERS technique was validated on parameters such as linearity, accuracy, precision, robustness, matrix effects, limit of quantification (LOQ), specificity, retention time and ion ratio as per SANTE (Directorate General for Health and Food Safety) guidelines to attest to the specificity, accuracy and precision of the analytical method in estimating insecticide residues in and on broccoli heads and cropped soil. The LOQ of the method for all three insecticides was 0.01 mg/kg. The initial deposits of cyantraniliprole, flubendiamide and acetamiprid reduced to half of its concentration in 1.873-2.354, 1.975-2.484 and 1.371-1.620 days, respectively. No residues were detected in broccoli-cropped soil at harvest time (30 days after last spray). The proposed maximum residue limits (MRLs) of 1.5, 0.5-0.9 and 2.0-3 mg/kg for cyantraniliprole, flubendiamide and acetamiprid were calculated using the Organisation for Economic Co-operation and Development MRL calculator. The acute and chronic dietary risk assessment of the tested insecticides identified no appreciable dietary risk to the Indian population from the consumption of broccoli heads. The findings of no dietary risk highlight the importance of informed pesticide usage in broccoli and the proposed MRL derived from this study offers crucial guidelines for the regulatory authorities, ensuring the safety of broccoli consumption.

Synthesis of in-situ magnetized MOF-cellulose membranes for high-efficiency enrichment of diamide insecticides in vegetables and determination by LC-MS/MS

This study presents a novel, eco-friendly composite adsorbent material designed for the magnetic solid-phase extraction of diamide insecticides from vegetable samples. The membrane, denoted as Fe-MMm, was incorporated with a cellulose framework embedded with Metal-Organic Frameworks (MOFs) and Multi-Walled Carbon Nanotubes (MWCNTs) magnetized with Fe3O4. This innovative material streamlined the conventional solid-phase extraction process, simplifying the sample pre-treatment. By combining it with liquid chromatography tandem mass spectrometry (LC-MS/MS), the method achieves significantly enhanced extraction efficiency through systematic optimization of experimental parameters, including adsorbent selection, pH, ionic strength, adsorption time, and elution time. The method had a wide linear range of 0.1-1000 ng/mL and an exceptionally low detection limit ranging from 0.023 to 0.035 ng/mL. The successful identification of diamide insecticides in vegetable samples underscores the potential of Fe-MMm as a robust material for sample pretreatment in analytical applications.

Chlorantraniliprole in foods: Determination, dissipation and decontamination

Chlorantraniliprole (CAP) is the first commercially available anthranilic diamide insecticide that targets ryanodine receptors. However, excessive use of CAP can lead to persistent contamination on treated foods and adverse effects on human wellness. The current review focuses on CAP residue analysis in foods by using chromatographic techniques. QuEChERS (quick, easy, cheap, effective, rugged and safe) is the most widely used sample preparation strategy and liquid chromatography tandem mass spectrometry is the predominant analytical method for various food matrices including vegetable, fruit, grain, fish and so on. Moreover, this review summarizes the dissipation pattern of CAP on foods and found it usually dissipates fast on plant in open-field environment. For decontamination, common culinary cleaning methods could effectively remove CAP from vegetables. Finally, some new directions are proposed for better advancement.

Inducible Gut-Specific Carboxylesterase SlCOE030 in Polyphagous Pests of Spodoptera litura Conferring Tolerance between Nicotine and Cyantraniliprole

Insecticides tolerance in herbivorous arthropods is associated with preadaptation to host plant allelochemicals. However, how plant secondary metabolites activate detoxifying metabolic genes to develop tolerance remains unclear. Herein, the tolerance of Spodoptera litura larvae to cyantraniliprole was increased after nicotine exposure. An S. litura α esterase, SlCOE030, was predominantly expressed in the midgut and induced after exposure to cyantraniliprole, nicotine, and cyantraniliprole plus nicotine. Drosophila melanogaster with ectopically overexpressed SlCOE030 enhanced cyantraniliprole and nicotine tolerance by 4.91- and 2.12-fold, respectively. Compared to UAS-SlCOE030 and Esg-GAL4 lines, the Esg > SlCOE030 line laid more eggs after nicotine exposure. SlCOE030 knockdown decreased the sensitivity of nicotine-treated S. litura larvae to cyantraniliprole. Metabolism assays indicated that recombinant SlCOE030 protein metabolizes cyantraniliprole. Homology modeling and molecular docking analysis demonstrated that SlCOE030 exhibits effective affinities for cyantraniliprole and nicotine. Thus, insect CarEs may result in the development of cross-tolerance between synthetic insecticides and plant secondary metabolites.

Comprehensive Overview of Diamide Derivatives Acting as Ryanodine Receptor Activators

The world's hunger is continuously rising due to conflicts, climate change, pandemics (such as the recent COVID-19), and crop pests and diseases. It is widely accepted that zero hunger is impossible without using agrochemicals to control crop pests and diseases. Diamide insecticides are one of the widely used green insecticides developed in recent years and play important roles in controlling lepidopteran pests. Currently, eight diamine insecticides have been commercialized, which target the insect ryanodine receptors. This review summarizes the development and optimization processes of diamide derivatives acting as ryanodine receptor activators. The review also discusses pest resistance to diamide derivatives and possible solutions to overcome the limitations posed by the resistance. Thus, with reference to structural biology, this study provides an impetus for designing and developing diamide insecticides with improved insecticidal activities.

Uptake, translocation and distribution of cyantraniliprole in rice planting system

While cyantraniliprole has been frequently used in rice fields, knowledge of the uptake, translocation and distribution of cyantraniliprole in rice planting systems is still largely unexplored. Plant uptake is a crucial factor in determining how cyantraniliprole moves through the food chain. Understanding the uptake, translocation and distribution of cyantraniliprole in rice planting system is essential to predicting its accumulation in rice and potential human exposure. Herein, the uptake process of cyantraniliprole in a hydroponic-rice system was systematically investigated. Results showed that cyantraniliprole was easily absorbed by rice roots via a passive diffusion process through the apoplastic pathway and then translocated upward through the xylem, but its acropetal translocation was limited. Cyantraniliprole in shoots can also be downward translocated through the phloem, although only to a limited extent, showing rice plants' weak phloem movement capacity. Furthermore, cyantraniliprole had a short half-life in sediment-water system and dissipated faster in anaerobic than aerobic conditions. At the equilibrium stage of a sediment-water system, cyantraniliprole is preferentially partitioned to the solid phase. Our study provides a systematic insight into the uptake, translocation and distribution of cyantraniliprole in the rice planting system, which is very helpful for better field cyantraniliprole application and environmental risk assessment.

Enrichment of diamide insecticides from environmental water samples using metal-organic frameworks as adsorbents for determination by liquid chromatography tandem mass spectrometry

A series of metal-organic frameworks composed of different metal ions and organic linkers were facilely synthesized and used as adsorbents for five diamide insecticides for the first time. Among them, MIL-101-NH₂ performed much better than other materials due to extraordinarily high specific surface area, strong water stability, specific interaction with analytes. A sensitive method was developed with MIL-101-NH₂ based dispersive solid phase extraction combining with liquid chromatography tandem mass spectrometry (dSPE-LC-MS/MS). Important parameters including adsorbent amount, enrichment time, elution solvent and volume, pH and salt effect were investigated to achieve the best enrichment efficiency. At selected conditions, the proposed method showed ultrahigh sensitivity with limits of detection low to 0.01-0.03 ng/mL, which was 2-3 orders of magnitude lower than reported methods. Wide linearity in the range of 0.03-1000 ng/mL (chlorantraniliprole, cyantraniliprole) and 0.1-2000 ng/mL (flubendiamide, cyclaniliprole, tetrachlorantraniliprole) were established with satisfactory coefficient of determination. The method was successfully used for analyzing of diamide insecticides in environmental water samples and flubendiamide was detected in several samples. This work demonstrated the first example of developing novel nanomaterials in trace amount diamide insecticide enrichment from practical samples, which opens a new perspective in establishing nanomaterial-based sample preparation method for diamide insecticide analysis.

Determination of new generation amide insecticide residues in complex matrix agricultural food by ultrahigh performance liquid chromatography tandem mass spectrometry

Eight new generation amide insecticide residues analysis by multiwalled carbon nanotubes (MWCNs) cleanup, combined with QuEChERS and ultrahigh performance liquid chromatography tandem mass spectrometry has been developed and successfully applied in complex matrix such as orange, celery, onion, litchi, mango, shallot, chives, avocado, garlic. The matric effect of MWCNs is optimized and compared with ordinary cleanup materials. The results show that the performance of MWCNs is fine and effectively reduce matrix interference. Through chemical structure skeletons analyzed, chlorantraniliprole, bromoantraniliprole, and cyantraniliprole can cause same product ions of m/z 286.0 or 177.1 in the ESI⁺ mode, then tetrachlorantraniliprole and cyclaniliprole can produce collective ions of m/z 146.9 in the ESI^- mode. The coefficients (R²) were greater than 0.9990, the limit of quantification ranges from 0.03 to 0.80 μg/kg, the recovery rate ranges from 71.2 to 120%, and the relative standard deviation (RSD) ranges from 3.8 to 9.4%. The method is fast, simple, sensitive, and suitable for the rapid determination of amide pesticides in complex matrix agricultural food.

Assessing the ecological risk of pesticides should not ignore the impact of their transformation byproducts - The case of chlorantraniliprole

Risk assessments for pesticides typically focus on the compound itself ignoring the impact of its transformation byproducts. Challenges in isolating such byproducts (i.e. after application of pesticide in soil) often lead to underestimation of the real risk from such substances. The toxicological properties of these byproducts may differ from those of the parent pesticides; hence, special attention is required for these new emerging contaminants. In this study, two transformation byproducts of chlorantraniliprole were isolated from soil and identified, using nuclear magnetic resonance and high resolution mass spectrometry, as products of dechlorination (Z1) and bromination (Z2). Kinetic experiments revealed both byproducts degrade faster than chlorantraniliprole in soil (half-lives 38 & 43 d vs. 58 d). The ecological risk evaluation of chlorantraniliprole and its byproducts on soil bacterial community showed that they were all potentially harmful but they imposed different impacts on both alpha and beta diversities and co-occurrence networks of the bacterial community. Z2 had the biggest potential impact on soil bacteria and accounted as a high potential risk. By comparing their impacts on soil bacterial community, we confirm that ecological risk assessment necessitates the understanding of the environmental impacts of a substance as well as of its transformation byproducts.

Onsite/on-field analysis of pesticide and veterinary drug residues by a state-of-art technology: A review

Pesticides and veterinary drugs are generally employed to control pests and insects in crop and livestock farming. However, remaining residues are considered potentially hazardous to human health and the environment. Therefore, regular monitoring is required for assessing and legislation of pesticides and veterinary drugs. Various approaches to determining residues in various agricultural and animal food products have been reported. Most analytical methods involve sample extraction, purification (cleanup), and detection. Traditional sample preparation is time-consuming labor-intensive, expensive, and requires a large amount of toxic organic solvent, along with high probability for the decomposition of a compound before the analysis. Thus, modern sample preparation techniques, such as the quick, easy, cheap, effective, rugged, and safe method, have been widely accepted in the scientific community for its versatile application; however, it still requires a laboratory setup for the extraction and purification processes, which also involves the utilization of a toxic solvent. Therefore, it is crucial to elucidate recent technologies that are simple, portable, green, quick, and cost-effective for onsite and infield residue detections. Several technologies, such as surface-enhanced Raman spectroscopy, quantum dots, biosensing, and miniaturized gas chromatography, are now available. Further, several onsite techniques, such as ion mobility-mass spectrometry, are now being upgraded; some of them, although unable to analyze field sample directly, can analyze a large number of compounds within very short time (such as time-of-flight and Orbitrap mass spectrometry). Thus, to stay updated with scientific advances and analyze organic contaminants effectively and safely, it is necessary to study all of the state-of-art technology.

Transcriptomics and enzymology combined five gene expressions to reveal the responses of earthworms (Eisenia fetida) to the long-term exposure of cyantraniliprole in soil

Cyantraniliprole is a novel diamide insecticide that acts upon the ryanodine receptor (RyR) and has broad application prospects. Accordingly, it is very important to evaluate the toxicity of cyantraniliprole to earthworms (Eisenia fetida) because of their vital role in maintaining a healthy soil ecosystem. In this study, an experiment was set up, using four concentrations (0.1, 1, 5, and 10 mg/kg) and solvent control group (0 mg/kg), to investigate the ecotoxicity of cyantraniliprole to earthworms. Our results showed that, after 28 days of exposure to cyantraniliprole, both cocoon production and the number of juvenile earthworms had decreased significantly at concentrations of either 5 or 10 mg/kg. On day 14, we measured the activities of digestive enzymes and ion pumps in the intestinal tissues of earthworms. These results revealed that cyantraniliprole exposure caused intestinal damage in earthworm, specifically changes to its intestinal enzyme activity and calcium ion content. Cyantraniliprole could lead to proteins' carbonylation under the high-dose treatments (i.e., 5 mg/kg, 10 mg/kg). At the same time, we also found that cyantraniliprole can cause the abnormal expression of key functional genes (including HSP70, CAT, RYR, ANN, and CAM genes). Moreover, the transcriptomics data showed that exposure to cyantraniliprole would affect the synthesis of carbohydrates, proteins and lipids, as well as their absorption and transformation, while cyantraniliprole would also affect signal transduction. In general, high-dose exposure to cyantraniliprole causes reproductive toxicity, genotoxicity, and intestinal damage to earthworms.

Development and validation of a method for the analysis of five diamide insecticides in edible mushrooms using modified QuEChERS and HPLC-MS/MS

In this study, a new method for simultaneous determination of cyantraniliprole, chlorantraniliprole, tetrachlorantraniliprole, cyclaniliprole and flubendiamide in edible mushrooms by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) combined with a modified QuEChERS procedure. The samples were extracted using acetonitrile and then cleaned up by primary secondary amine (PSA) and octadecylsilane (C18). The determination of these insecticides was achieved in less than 5 min using an electrospray ionization source in positive mode (ESI+) for cyantraniliprole and chlorantraniliprole, while negative mode (ESI-) for tetrachlorantraniliprole, cyclaniliprole and flubendiamide. The linearities of the calibrations for all target compounds were acceptable (R² ≥ 0.9922). The limits of detection and quantification were 0.05-2 μg kg^-1 and 5 μg kg^-1, respectively. Acceptable recoveries (73.5-110.2%) were acquired for these insecticides with RSDs less than 12.7%. The results demonstrated that the proposed method was effective and convenient for the determination of these insecticides in edible mushrooms.

Growth, DNA damage and biochemical toxicity of cyantraniliprole in earthworms (Eisenia fetida)

Cyantraniliprole is a second-generation diamide insecticide that exhibited excellent biological efficacy against a variety of pests. To assess the toxic impact of cyantraniliprole on earthworms, the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), activities of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST), as well as DNA damage were measured after exposed to five cyantraniliprole concentrations ranging from 0 to 10.00 mg/kg for 7, 14, 21 and 28 days. In most treatment groups, the ROS levels increased significantly before exposure time of 14 days and then returned to normal levels. However, the SOD and CAT activities showed different response with activities were first significantly decreased and subsequently increased. The peroxidase (POD) activity showed no significant differences between treatment and control groups at first and then significantly increased. However, the opposite pattern characterized the GST activity. Also, maybe being dose-dependent before 14 days. The MDA concentration was used as a measure of lipid peroxidation (LPO). During experiment period, the MDA concentrations significantly increased when treated by this pesticide. The olive tail moment (OTM) was used as a measure of DNA damage. At higher concentrations of cyantraniliprole and longer exposure times, the OTM gradually increased, and DNA damage in the earthworms gradually increased. The weight of the high-dose (i.e., 5 mg/kg, 10 mg/kg) earthworms showed a significant trend of decrease phenomenon. Overall, the results suggest that sub-chronic exposure to cyantraniliprole causes DNA damage and LPO, weight loss and growth inhibition, leading to antioxidant defence responses in earthworms.

Simultaneous Determination of Five Diamide Insecticides in Food Matrices Using Carbon Nanotube Multiplug Filtration Cleanup and Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry

In this study, an analytical method was developed and validated for simultaneous determination of five diamide insecticides (chlorantraniliprole, cyantraniliprole, flubendiamide, cyclaniliprole, and tetrachlorantraniliprole) in food matrices. Determination of the latter two diamide compounds is first reported. Samples were cleaned up by multiplug filters containing carbon nanotubes (CNT) or hydrophilic-lipophilic balanced copolymers (HLB) and classic dispersive solid phase extraction (d-SPE) procedures, respectively. The CNT multiplug filter performed the best in terms of process rapidity and cleanup efficiency; thus, it was finally chosen for sample cleanup. Instrumental analysis was completed in 5 min using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Mean recoveries of the five diamides ranged from 84.3 to 110.0%, with intraday and interday relative standard deviations (RSD) of less than 13.5%. Limits of quantitation (LOQ) of all analytes ranged from 0.005 to 0.01 mg kg^-1 in different matrices. The results indicate this method is reliable for monitoring the five diamide insecticides in various foods.

Growth, reproduction and biochemical toxicity of chlorantraniliprole in soil on earthworms (Eisenia fetida)

Diamide insecticides have become the fourth most commonly used insecticide class in the world. Chlorantraniliprole (CAP) is a first-generation diamide insecticide with broad application potential. In this experiment, the eco-toxicity of CAP in soil at 0.1, 1.0, 5.0 and 10.0mg/kg on earthworms (Eisenia fetida) was evaluated during a 42 d exposure. More specifically, the environmental fate and transport of CAP between soil and earthworms was monitored during the exposure period. The present results indicated that the CAP contents of 0.1, 1.0, 5.0 and 10.0mg/kg treatments decreased to no more than 20% in the soil after 42 d of exposure. The accumulation of CAP in earthworms was 0.03, 0.58, 4.28 and 7.21mg/kg earthworm (FW) at 0.1, 1.0, 5.0 and 10.0mg/kg after 42 d of exposure. At 0.1mg/kg and 1.0mg/kg, CAP had no effect on earthworms during the exposure period. The weight of earthworms was significantly reduced at 5.0 and 10.0mg/kg at 28 and 42 days after CAP application. After the 14th day, CAP induced excess production of reactive oxygen species (ROS) at 5.0 and 10.0mg/kg, resulting in oxidative damage to biomacromolecules. We believe that CAP has a high risk potential for earthworms when used at 5.0 and 10.0mg/kg.

Rational dose of insecticide chlorantraniliprole displays a transient impact on the microbial metabolic functions and bacterial community in a silty-loam paddy soil

Chlorantraniliprole (CAP) is a newly developed insecticide widely used in rice fields in China. There have been few studies regarding its effects on soil microbial functional diversity and bacterial community composition. An 85-day microcosm experiment was performed to reveal the dissipation dynamics of CAP under different application doses in a silty-loam paddy soil in subtropical China. The half-life of CAP was 51.3 and 62.5d for low (1mgkg^-1) and high (10mgkg^-1) application dose, respectively. We used a combination of community level physiological profile (CLPP) and 16S rRNA gene sequencing analysis to get insights into the soil microbial features responded to CAP during the experiment. Non-metric multidimensional scaling (NMDS) performed on CLPP and the sequence results indicated that the soil microbial functional diversity and bacterial community composition were significantly changed by CAP application at day 14, and recovered to the similar level as no CAP treatment (CK) under low dose of CAP at day 36. However, high dose of CAP imposed longer effect on these soil microbial features, and was still significantly different from CK at day 36. Mcrobial taxa analysis at phylum level showed that high dose of CAP decreased the relative abundance of Nitrospirae at day 14, while increased Bacteroidetes and decreased Actinobacteria, Nitrospirae, and Firmicutes at day 36 in relative to CK. Low dose of CAP only increased Crenarchaeota and decreased Nitrospirae at day 14. The response ratio (RR) analysis was used to quantify significant responses of OTUs to different doses of CAP and found that CAP significantly affected the microbes involving the N transformation. This study provides a basic information to aid in the development of application regulations regarding the safe use of CAP in soil and inspire us to apply CAP at rational dose to minimize its ecotoxicity on soil microbes.

Impact of Simulated California Rice-Growing Conditions on Chlorantraniliprole Partitioning

Chlorantraniliprole (3-bromo-N-[4-chloro-2-methyl-6-(methylcarbamoyl)phenyl]-1-(3-chloro-2-pyridine-2-yl)-1H-pyrazole-5-carboxamide, CAP; water solubility 1.023 mg·L^-1) was recently registered for application on California rice fields. Air- and soil-water partitioning of CAP were investigated under simulated California rice field conditions through calculation of K_H and Δ_awH and a batch equilibrium method following OECD 106 guidelines, respectively. K_H and Δ_awH were determined to be 1.69 × 10^-16 - 2.81 × 10^-15 atm·m³·mol^-1 (15-35 °C) and 103.68 kJ·mol^-1, respectively. Log(K_oc) ranged from 2.59 to 2.96 across all soil and temperature treatments. Log(K_F) ranged from 0.61 to 1.14 across all soil, temperature, and salinity treatments. Temperature and salinity increased sorption significantly at 35 °C (P < 0.05) and 0.2 M (P < 0.0001), respectively, while soil properties impacted sorption across all treatments. Overall results, corroborated using the Pesticides in Flooded Applications Model, indicate that volatilization of CAP is not a major route of dissipation and sorption of CAP to California rice field soils is moderately weak and reversible.

Development of a monoclonal antibody-based ELISA for the detection of the novel insecticide cyantraniliprole

A highly sensitive and selective immunoassay was developed for the analysis of cyantraniliprole. The concentrations of cyantraniliprole residues in pakchoi samples determined by ELISA agreed with those by the HPLC method.

Residues of cyantraniliprole and its metabolite J9Z38 in rice field ecosystem

A simple and reliable analytical method was developed to detect cyantraniliprole (HGW86) and its metabolite J9Z38 in rice straw, paddy water, brown rice, and paddy soil. The fate of cyantraniliprole and its metabolite J9Z38 in rice field ecosystem was also studied. The target compounds were extracted using acetonitrile, cleaned up on silicagel or strong anion exchange column, and analyzed by ultra-performance liquid chromatography-tandem mass spectrometry. The average recoveries of cyantraniliprole and J9Z38 in rice straw, paddy water, brown rice, and paddy soil ranged from 79.0% to 108.6%, with relative standard deviations of 1.1-10.6%. The limits of quantification of cyantraniliprole and J9Z38 were 18 and 39μgkg(-1) for rice straw, 2.8 and 5.0μgkg(-1) for paddy water, 4.3 and 6.3μgkg(-1) for brown rice, and 3.9 and 5.3μgkg(-1) for paddy soil. The trial results showed that the half-lives of cyantraniliprole were 3.2, 4.4, and 6.3d in rice straw and 4.9, 2.0, and 6.2d in paddy water in Zhejiang, Hunan, and Shandong, respectively. The respective final residues of cyantraniliprole and J9Z38 in brown rice were lower than 0.05 and 0.02mgkg(-1) after 14d of pre-harvest interval. The maximum residue limit of cyantraniliprole at 0.1mgkg(-1) and dosage of 100g a.i.hm(-2), which could be considered safe to human beings and animals, were recommended.

Determination of cyantraniliprole and its major metabolite residues in pakchoi and soil using ultra-performance liquid chromatography-tandem mass spectrometry

A rapid, simple and reliable analytical method was developed for the determination of cyantraniliprole and its major metabolite J9Z38 in pakchoi and soil by using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample preparation approach is known as QuEChERS, which stands for quick, easy, cheap, effective, rugged and safe. Samples were extracted with acetonitrile, and cleaned up with dispersive primary and secondary amine sorbent before analysis by UPLC-MS/MS. The limit of quantitation for cyantraniliprole and J9Z38 was 0.01 mg/kg in both pakchoi and soil. Average recoveries of cyantraniliprole and J9Z38 at three fortified levels (0.01, 0.05, 0.1 mg/kg) ranged from 77.8% to 102.5% with relative standard deviation of 1.6%-8.9%. This method has been applied to the analysis of cyantraniliprole and J9Z38 residues in real pakchoi and soil samples selected from field. The results of the residue dynamic experiment showed that the half-life of cyantraniliprole ranged from 2.9 to 6.4 days in pakchoi and 8.7 to 18.2 days in soil, respectively. The final residual levels of cyantraniliprole in pakchoi and soil from Guangdong and Shanghai were below 0.20 and 0.10 mg/kg, respectively; similarly, the final residual levels of J9Z38 in pakchoi and soil from Guangdong and Shanghai were <0.07 and 0.01 mg/kg. These results will be helpful in setting maximum residue limit guidance for cyantraniliprole in pakchoi in China.

Development and validation of QuEChERS method for estimation of chlorantraniliprole residue in vegetables

An easy, simple and efficient analytical method was standardized and validated for the estimation of residues of chlorantraniliprole in different vegetables comprising brinjal, cabbage, capsicum, cauliflower, okra, and tomato. QuEChERS method was used for the extraction and cleanup of chlorantraniliprole residues on these vegetables. Final clear extracts of ethyl acetate were concentrated under vacuum and reconstituted into high performance liquid chromatograph (HPLC) grade acetonitrile, and residues were estimated using HPLC equipped with PDA detector system, C(18) column and confirmed by liquid chromatograph mass spectrometer (LC-MS/MS), and high performance thin layer chromatograph (HPTLC). HPLC grade acetonitrile:water (80:20, v/v) was used as mobile phase @ 0.4 mL/min. Chlorantraniliprole presented distinct peak at retention time of 9.82 min. Consistent recoveries ranging from 85% to 96% for chlorantraniliprole were observed when samples were spiked at 0.10, 0.25, 0.50, and 1.00 mg/kg levels. The limit of quantification of this method was worked out to be 0.10 mg/kg.

Residues of chlorantraniliprole in rice field ecosystem

The fate of chlorantraniliprole was studied in rice field ecosystem, and a simple and reliable analytical method was developed for determination of chlorantraniliprole in soil, rice straw, paddy water and brown rice. Chlorantraniliprole residues were extracted from samples with acetonitrile. The extract was cleaned up with QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method, and determined by high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The average recoveries were 76.9-82.4% from soil, 83.6-89.3% from rice straw, 95.2-103.1% from paddy water and 84.9-87.7% from brown rice. The relative standard deviation was less than 15%. The limits of detection (LODs) of chlorantraniliprole calculated as a sample concentration (S/N ratio of 3) were 0.012 μg L(-1) for paddy water, 0.15 μg kg(-1) for soil, brown rice and rice straw. The results of the kinetics study of chlorantraniliprole residue showed that chlorantraniliprole degradation in soil, water and rice straw coincided with C=0.01939e(-0.0434t), C=0.01425e(-0.8111t), and C=1.171e(-0.198t), respectively; the half-lives were about 16.0 d, 0.85 d and 3.50 d, respectively. The degradation rate of chlorantraniliprole in water was the fastest, followed by rice straw. The final residues of chlorantraniliprole on brown rice were lower than maximum residue limit (MRL) of 0.02 mg kg(-1) after 14 d Pre-Harvest Interval (PHI). Therefore, a dosage of 150 mL a.i.hm(-2) was recommended, which could be considered as safe to human beings and animals.

Evaluation of a modified QuEChERS extraction of multiple classes of pesticides from a rice paddy soil by LC-APCI-MS/MS

A new method for the determination of clomazone, fipronil, tebuconazole, propiconazole, and azoxystrobin in samples of rice paddy soil is presented. The extraction of the pesticides from soil samples was performed by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Some extraction conditions such as salt addition, sample acidification, use of buffer, and cleanup step were evaluated. The optimized method dealt with a single extraction of the compounds under study with acidified acetonitrile, followed by the addition of MgSO(4) and NaCl prior to the final determination by liquid chromatography-atmospheric chemical pressure ionization-tandem mass spectrometry. Validation studies were carried out in soil samples. Recoveries of the spiked samples ranged between 70.3 and 120% with relative standard deviation lower than 18.2%. The limits of quantification were between 10 and 50 μg kg(-1). The method was applied to the analysis of real samples of soils where rice is cultivated.

Determination of cyantraniliprole and its major metabolite residues in vegetable and soil using ultra-performance liquid chromatography/tandem mass spectrometry

A rapid, highly sensitive and selective method was developed for the determination of the cyantraniliprole and its major metabolite J9Z38 in cucumber, tomato and soil by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Target compounds were extracted with acetonitrile and an aliquot cleaned with primary and secondary amine. Two pairs of precursor product ion transitions for cyantraniliprole and J9Z38 were measured and evaluated. Average recoveries for cucumber, tomato and soil at three levels (10, 50 and 100 µg/kg) ranged from 74.7 to 96.2% with intra-day relative standard deviation (RSD) of 2.6-15.1% and inter-day RSD of 3.4-13.3%. The limit of quantitation for cyantraniliprole and J9Z38 were determined to be 5 and 10 µg/kg in samples (cucumber, tomato and soil), respectively. This method was used to determine the cyantraniliprole and J9Z38 residues in real cucumber, tomato and soil samples for studies on their dissipation. The trial results showed that the half-lives of cyantraniliprole obtained after treatments were 2.2, 2.8 and 9.5 days in cucumber, tomato and soil in Zhejiang, respectively, and that the average levels of cyantraniliprole and J9Z38 residues in cucumber and tomato were all <0.01 mg/kg with the interval of 10 days after treatment.