孝感市桃果实的4种拟除虫菊酯类杀虫剂残留消解及膳食摄入风险评估

Residue dissipation and dietary intake risk assessment of 4 kinds of pyrethroid insecticides in Prunus persica L. fruits from Xiaogan City

中文关键词:  拟除虫菊酯  桃  农药残留  膳食风险评估  消解规律  

英文关键词:pyrethroids  Prunus persica L.  pesticide residues  dietary risk assessment  dissipation dynamics

中文摘要:

      目的 了解拟除虫菊酯类杀虫剂在孝感市桃果中的残留及消解规律, 评估其膳食摄入风险。方法 桃果样品经匀浆处理后, 以乙腈为提取溶剂提取目标化合物, 提取液经N-丙基乙二胺与弗罗里硅土联合净化后, 采用RTX-5毛细管柱(30 m×0.25 mm, 0.25 μm)进行色谱分离, 电子捕获检测器检测, 采用外标法进行定量分析, 测定不同稀释倍数处理下施药后0~23 d果实中的残留水平。结果 方法学验证结果表明, 4种拟除虫菊酯类杀虫剂在0.01~1.00 mg/kg浓度范围内线性关系良好(r2≥0.9942), 平均回收率为78.85%~97.62%, 相对标准偏差为2.12%~6.85%, 最低检出限和定量限分别为0.001 mg/kg和0.003 mg/kg, 表明该检测方法具有良好的灵敏度和准确性。田间试验结果显示, 4种杀虫剂在桃果实中的残留量均随时间延长下降, 符合一阶动力学消解规律, 半衰期为2.60~12.95 d。随施药浓度增加, 初始残留量升高; 施药后5 d残留降至初始值的20%~40%, 16~23 d时多数处理的残留已低于0.50 mg/kg, 符合食品安全采收间隔要求。膳食风险评估结果表明, 4种农药在不同稀释倍数下的全国估算日摄入量均远低于每日允许摄入量, 风险商为0.002~0.103(均<1)。结论 在常规施药浓度及采收间隔条件下, 对消费者健康风险较低, 基于消解动力学数据, 建议消解较快的甲氰菊酯与高效氯氟氰菊酯, 采收间隔期建议不低于16 d; 对于持效性强的高效氯氰菊酯与溴氰菊酯, 建议间隔期延长至23 d。本研究为孝感市桃果安全用药及拟除虫菊酯类杀虫剂科学施用与管理提供了重要科学依据。

英文摘要:

      Objective To understand the residues and dissipation dynamics of pyrethroid insecticides in Prunus persica L. fruits from the Xiaogan City and assess their dietary intake risk. Methods Prunus persica L. fruit samples were homogenized, and the target compounds were extracted using acetonitrile as the extraction solvent. The extracts were purified using a combination of primary secondary amine and Florisil. Chromatographic separation was performed on an RTX-5 capillary column (30 m×0.25 mm, 0.25 μm), and detection was carried out using an electron capture detector. Quantification was achieved by the external standard method to determine the residue levels in fruits at 0–23 days after application under different dilution treatments. Results Method validation results showed that the 4 kinds of pyrethroid insecticides exhibited good linearity within the concentration range of 0.01–1.00 mg/kg (r2≥0.9942). The average recoveries ranged from 78.85% to 97.62%, with relative standard deviations between 2.12% and 6.85%. The limits of detection and limits of quantitation were 0.001 mg/kg and 0.003 mg/kg, respectively, indicating that the method possesses satisfactory sensitivity and accuracy. Field trial results demonstrated that the residue levels of the 4 kinds of insecticides in peach fruits decreased significantly over time, following first-order kinetic dissipation patterns, with half-lives ranging from 2.60 to 12.95 days. The initial residue concentration increased significantly with higher application concentrations. Residues decreased to 20%–40% of the initial values by day 5 after application, and most treatments showed residue levels below 0.50 mg/kg at 16–23 days, meeting the pre-harvest interval requirements for food safety. Dietary risk assessment indicated that the national estimated daily intakes of the 4 kinds of pesticides under different dilution treatments were substantially lower than their corresponding acceptable daily intakes. The risk quotients ranged from 0.002 to 0.103 (all<1). Conclusion Under regular application concentrations and harvest interval conditions, the health risk to consumers is relatively low. Based on the dissipation kinetic data, it is recommended that for the rapidly degrading fenpropathrin and lambda-cyhalothrin, the pre-harvest interval should be no less than 16 days; for the more persistent beta-cypermethrin and deltamethrin, the interval should be extended to 23 days. This study provides important scientific evidence for the safe application of pyrethroid insecticides in Prunus persica L. orchards in the Xiaogan City and offers technical support for their scientific use and management.