Costa Anna I G, Queiroz Maria E L R, Neves Antônio A, de Sousa Flaviane A, Zambolim Laércio
Department of Chemistry, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brazil.
Department of Chemistry, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brazil.
Food Chem. 2015 Aug 15;181:64-71. doi: 10.1016/j.foodchem.2015.02.070. Epub 2015 Feb 20.
This work describes the optimization and validation of a method employing solid-liquid extraction with low temperature partitioning (SLE/LTP) together with analysis by gas chromatography with electron capture detection (GC/ECD) for the determination of nine pesticides (chlorothalonil, methyl parathion, procymidone, endosulfan, iprodione, λ-cyhalothrin, permethrin, cypermethrin, and deltamethrin) in lettuce. The method was found to be selective, accurate, and precise, with means recovery values in the range of 72.3-103.2%, coefficients of variation ⩽ 12%, and detection limits in the range 0.4-37 μg kg(-1). The matrix components significantly influence the chromatographic response of the analytes (above 10%). The optimized and validated method was applied to determine the residual concentrations of the fungicides iprodione and procymidone that had been applied to field crops of lettuce. The maximum residual concentrations of the pesticides in the lettuce samples were 13.6 ± 0.4 mg kg(-1) (iprodione) and 1.00 ± 0.01 mg kg(-1) (procymidone), on the day after application of the products.
本研究描述了一种采用低温分配固液萃取（SLE/LTP）结合电子捕获检测气相色谱法（GC/ECD）测定生菜中9种农药（百菌清、甲基对硫磷、腐霉利、硫丹、异菌脲、高效氯氟氰菊酯、氯菊酯、氯氰菊酯和溴氰菊酯）的方法的优化与验证。结果表明，该方法具有选择性、准确性和精密度，平均回收率在72.3% - 103.2%之间，变异系数≤12%，检测限在0.4 - 37 μg kg⁻¹范围内。基质成分对分析物的色谱响应有显著影响（超过10%）。将优化并验证后的方法应用于测定施用于生菜田间作物的杀菌剂异菌脲和腐霉利的残留浓度。在施用产品后的第二天，生菜样品中农药的最大残留浓度分别为13.6 ± 0.4 mg kg⁻¹（异菌脲）和1.00 ± 0.01 mg kg⁻¹（腐霉利）。
