气相色谱法测定苹果和土壤中的高效氯氟氰菊酯

建立了改进的QuEChERS-气相色谱检测苹果和土壤中高效氯氟氰菊酯残留的分析方法，考察和评价了苹果和土壤两种基质对高效氯氟氰菊酯的基质效应。苹果和土壤样品均用乙腈提取，经石墨化碳黑（GCB）净化后直接进样分析。结果表明：在优化后的QuEChERS条件下，高效氯氟氰菊酯在0.05~10 mg/L范围内线性关系良好，相关系数（R²）大于0.999，检出限为0.12~0.15 μg/kg，定量限为0.38~0.50 μg/kg。用基质标准曲线定量时，高效氯氟氰菊酯在土壤和苹果中的回收率分别为88.29%~97.65%和80.70%~98.69%。苹果和土壤样品对高效氯氟氰菊酯都表现出基质增强效应。该方法的回收率均能达到残留分析要求，用基质配制标准溶液能够有效、方便地校正气相色谱-电子捕获检测器测定高效氯氟氰菊酯残留时的基质效应，且能应用于苹果和土壤实际样品的检测。

Determination of lambda-cyhalothrin in apples and soil by gas chromatography

A modified QuEChERS-gas chromatography method was developed to determine the residues of lambda-cyhalothrin in apples and soil. Moreover, the matrix effects in apples and soil were investigated and evaluated. The apple and soil samples were extracted with acetonitrile and purified by graphitized carbon black (GCB). The linearity of lambda-cyhalothrin was good in the range of 0.05-10 mg/L with correlation coefficients (R²) more than 0.999. The limits of detection and limits of quantification were 0.12-0.15 μg/kg and 0.38-0.50 μg/kg, respectively. With the matrix-matched calibration, the recoveries were 88.29%-97.65% and 80.70%-98.69% in soil and apples, respectively, which were in the acceptable range. Matrix enhancement effects were observed in the apple and soil samples. The established method can be applied on the residual analysis of lambda-cyhalothrin in actual apple and soil samples. The matrix-matched calibration solution can efficiently compensate the matrix effects of the lambda-cyhalothrin in gas chromatography-electron capture detector (GC-ECD) analysis.