Determination of the dissipation dynamics and residue behaviors of chlorantraniliprole in sugarcane and soil by LC-MS/MS

A Rapid and Sensitive Gold Nanoparticle-Based Lateral Flow Immunoassay for Chlorantraniliprole in Agricultural and Environmental Samples

Chlorantraniliprole (CAP) is a new type of diamide insecticide that is mainly used to control lepidopteran pests. However, it has been proven to be hazardous to nontarget organisms, and the effects of its residues need to be monitored. In this study, five hybridoma cell lines were developed that produced anti-CAP monoclonal antibodies (mAbs), of which the mAb originating from the cell line 5C5B9 showed the highest sensitivity and was used to develop a gold nanoparticle-based lateral flow immunoassay (AuNP-LFIA) for CAP. The visible limit of detection of the AuNP-LFIA was 1.25 ng/mL, and the detection results were obtained in less than 10 min. The AuNP-LFIA showed no cross-reactivity for CAP analogs, except for tetraniliprole (50%) and cyclaniliprole (5%). In the detection of spiked and blind samples, the accuracy and reliability of the AuNP-LFIA were confirmed by a comparison with spiked concentrations and verified by ultra-performance liquid chromatography-tandem mass spectrometry. Thus, this study provides the core reagents for establishing CAP immunoassays and a AuNP-LFIA for the detection of residual CAP.

Uncovering the Dissipation of Chlorantraniliprole in Tomatoes: Identifying Transformation Products (TPs) and Coformulants in Greenhouse and Laboratory Studies by UHPLC-Q-Orbitrap-MS and GC-Q-Orbitrap-MS

The present study addressed the dissipation of the insecticide chlorantraniliprole in tomatoes treated with Altacor 35 WG under laboratory and greenhouse conditions, as well as the identification of transformation products (TPs) and coformulants, performing suspect screening analysis. Analyses were performed by ultra-high-performance liquid and gas chromatography coupled to quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-MS and GC-Q-Orbitrap-MS). In all cases, chlorantraniliprole was fitted to a biphasic kinetic model, with R² values greater than 0.99. Dissipation was noticeably faster in greenhouse studies, in which even 96% dissipation was achieved over 53 days. One TP, IN-F6L99, was tentatively identified in both greenhouse and laboratory studies and was semiquantified by using chlorantraniliprole as the analytical standard, yielding a top value of 354 μg/kg for laboratory studies, whereas values for greenhouse studies fell under the limit of quantitation (LOQ). Finally, a total of 15 volatile coformulants were identified by GC-Q-Orbitrap-MS.

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.

Dissipation Kinetics and Safety Evaluation of Flonicamid in Four Various Types of Crops

The chemical insecticide flonicamid is widely used to control aphids on crops. Differences among crops make the universality of detection methods a particularly important consideration. The aim of this study was to establish a universal, sensitive, accurate and efficient method for the determination of flonicamid residues in peach, cucumber, cabbage and cotton. QuEChERS pretreatment was combined with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A satisfactory recovery rate of 84.3-99.3% was achieved at three spiking levels, and the relative standard deviation (RSD) was 0.41-5.95%. The limit of quantification (LOQ) of flonicamid in the four matrices was 0.01 mg/kg. The residue and dissipation kinetics of flonicamid in four types of crops in various locations were determined by using the optimized method. The results showed that flonicamid had a high dissipation rate in the four different types of crops and a half-life in the different matrices and locations of 2.28-9.74 days. The terminal residue of flonicamid was lower than the maximum residue limit (MRL). The risk quotient (RQ) of flonicamid was 4.4%, which is significantly lower than 100%. This result shows that the dietary risk presented by using flonicamid at the maximum recommended dose is low and acceptable. The comprehensive long-term dietary risk assessment of flonicamid performed in this study provides a reference for the protection of consumer health and safe insecticide use.

Dissipation behavior, residue transfer, and safety evaluation of chlorantraniliprole and indoxacarb during tea growing and brewing by ultrahigh-performance liquid chromatography-tandem mass spectrometry

A reliable and simple analytical method was developed and validated to simultaneously determine chlorantraniliprole and indoxacarb in tea using ultrahigh-performance liquid chromatography-tandem mass spectrometry. The average recoveries of chlorantraniliprole were in the range of 86-110%, with the precision of intraday (n = 5) and interday (n = 15) ranging from 1.9 to 8.4% and from 2.4 to 8.8%, respectively. The average recoveries of indoxacarb were in the range 81-105%, with the precision of intraday (n = 5) and interday (n = 15) ranging from 2.0 to 9.8% and from 2.7 to 9.1%, respectively. The limits of quantification (LOQs) were all 0.01 mg/kg. The results based on the supervised field trials showed that chlorantraniliprole and indoxacarb in two tea samples followed first-order kinetics models with half-lives of 2.2-4.7 days and 2.5-3.5 days, which could be regarded as a moderately degrading pesticide. The terminal residues of chlorantraniliprole and indoxacarb in made tea were below 6.7 and 4.5 mg/kg, respectively, lower than their corresponding maximum residue limits (MRLs) established by several major countries and organizations (50 and 5 mg/kg). The leaching rates of chlorantraniliprole and indoxacarb during the tea brewing ranged from 4.78 to 12.62% and 4.13 to 10.67%, respectively. The chronic intake risk quotient (RQc) values for chlorantraniliprole and indoxacarb were 0.24% and 35.10%, while the acute dietary risk assessment (RQa) value of indoxacarb was 5.8%, which were all much lower than 100%. The results in the present study indicated that the health risk posed by the chlorantraniliprole and indoxacarb mixture pesticides was negligible in tea for consumers at the recommended dosages.

Simultaneous determination of isoxaflutole and its two metabolites in corn under field conditions by LC-MS/MS

OBJECTIVE

An improved QuEChERS method was established and verified for simultaneous determination of isoxaflutole and its metabolites diketonitrile and benzoic acid analogue residues in corn and plants. This method was mainly used to study the digestion rule and final residue level of isoxaflutole and its metabolites in corn and plants. It was hoped that the safe use of isoxaflutole in corn can be achieved eventually.

METHOD

The method was completed by means of ultra-performance liquid chromatography with triple quadrupole mass spectrometry. The extraction of the target substance was through acetonitrile solution containing 1% acetic acid, and the purification was through primary secondary amine, octadecylsilane and graphitized carbon black sorbent.

RESULTS

In the method, the quantitative limits and detection limits of the three analytes were 0.005-0.01 and 0.001-0.003 mg kg^-1 respectively. The half-life of isoxaflutole in the plants in Shandong and Anhui was 36.4 and 42.1 days respectively, and the digestion dynamics all conformed to the first-order kinetics. The final residues of isoxaflutole in green corn and mature corn were less than 0.02 mg kg^-1 of the maximum residue limit set by the Codex Alimentarius Commission.

CONCLUSIONS

The residual amount of isoxaflutole in corn and plants at harvest time was acceptable when isoxaflutole was applied once at a dose of 121.5 g a.i. ha^-1 . © 2021 Society of Chemical Industry.

Determination of Market, Field Samples, and Dietary Risk Assessment of Chlorfenapyr and Tralopyril in 16 Crops

The frequent and massive use of chlorfenapyr has led to pesticide residues in crops, threatening food safety and human health. However, there is limited research on the detection of tralopyril, which is the major metabolite of chlorfenapyr with high toxicity. This study aimed to develop a novel, sensitive, and highly efficient method for the determination of chlorfenapyr and tralopyril residues in 16 crops. The optimized purification procedure provided satisfactory recovery of 76.6-110%, with relative standard deviations of 1.3-11.1%. The quantification values of pesticides in crop matrixes were all 0.01 μg kg^-1. The optimal method was adopted to determine the chlorfenapyr and tralopyril residues in field trials in 12 regions in China and monitor their residues in 16 agricultural products. The results of the dissipation and terminal residue experiments show that the final residue of chlorfenapyr was less than MRL (maximum residue limit) and no tralopyril was detected in the field samples. Moreover, the qualification proportion of these residues in market samples were up to 99.5%. The RQ (risk quotient) values of chlorfenapyr and chlorfenapyr with consideration of tralopyril were both apparently lower than an RQ of 100%, indicating an acceptable level. This research provides a thorough long-term dietary risk evaluation on chlorfenapyr and tralopyril and would provide reference for their scientific and safe utilization.

Residual behavior and risk assessment of butralin in peanut fields

Butralin is widely used to control single-leaf weeds and some dicotyledons. The application of butralin in the environment may cause residue beyond regulation criteria and residual toxicity. Therefore, it is important to detect and supervise the dissipation behavior of butralin in edible raw food and in the environment. The aim of this study was to monitor butralin in peanuts and soil under farmland conditions and examine the likely dietary risk assessment of butralin for Chinese people on the basis of residual concentrations. A method for the analysis of butralin residue and its dissipation in peanut plants and soil under field conditions was investigated. The results show that an analytical method for the quantization of butralin in peanuts and soil utilizing gas chromatography with electron capture detection (GC-ECD) was developed. Standard recovery experiments using three different butralin spiking levels of 0.01, 0.1, and 1.0 mg kg^-1 in different samples (i.e., peanut kernels, shell, seedling, stalk, and soil) were conducted. The recoveries of butralin from all matrices ranged from 86 to 108% with relative standard deviations from 3 to 6% (n = 5). The limit of quantification (LOQ) of the method was 0.01 mg kg^-1. After storage at - 20 °C for 365 days, the degradation rate of residues of butralin in peanut kernels was less than 30%, which met the storage stability test criteria for pesticide residues in stored commodities of plant origin. The dissipation half-lives of butralin ranged from 4.2 to 6.6 days and 4.6 to 6.6 days in peanut seedlings and soil, respectively, in farmland ecosystems. At the normal harvest time, the final residue concentrations of butralin in peanuts and soil were all below the LOQ. The final total risk quotient (RQ) values were much lower than RQ = 100%, which indicated that the long-run fitness risk associated with butralin residue in different groups of registered crops is correspondingly low for people in China. The current research results could offer guidance for the rational use of butralin and provide data support for the building of maximum residue limits (MRLs) in China.