气相色谱-质谱法测定水-沉积物系统中13种拟除虫菊酯类农药

建立了水-沉积物系统中13种拟除虫菊酯类农药的残留分析方法。样品采用固相萃取和加压流体萃取法分别作为水和沉积物的前处理方法，利用气相色谱-质谱（GC-MS)在选择离子扫描模式下进行检测，内标法定量。结果表明，13种拟除虫菊酯类农药在一定浓度范围内线性关系良好 (R2 ≥ 0.995)；水中添加水平在0.50~50 μg/L范围内时回收率为83%~104%，RSD (n = 6) 为0.73%~6.8%；沉积物中添加水平在5.0~50 μg/kg范围内时回收率为73%~92%，RSD (n = 6) 为0.63%~5.3%。方法的检出限为1.0~7.0 μg/L，13种拟除虫菊酯类农药在水中的检出限 (LOD) 为0.50 μg/L，在沉积物中的定量限（LOQ）为5.0 μg/kg。该方法灵敏度高、操作简便、重现性好，适用于水-沉积物系统中拟除虫菊酯类农药的快速检测和确证。

Determination of 13 pyrethroids in water and sediment system by gas chromatography-mass spectrometry

A residue analytical method was developed for the simultaneous determination of 13 pyrethroid pesticides in water-sediment system. Solid-phase extraction (SPE) and pressurized fluid extraction (PFE) were used as sample preparation method for water and sediment, respectively. Then gas chromatography-mass spectrometry (GC-MS) was used to detect the analytes in selective ion monitor (SIM) mode with internal standard method for quantification. The results showed that the linear relationship for the 13 pyrethroids was good with the correlation coefficient (R2) ≥ 0.995. The recoveries of the pyrethroids were 83%-104% and the relative standard deviation (RSD, n = 6) were 0.73%-6.8% at the spiking levels of 0.50-50 μg/L in water. The recoveries of the pyrethroids were 73%-92% and the RSD (n = 6) were 0.63%-5.3% at the spiking levels of 5.0-50 μg/kg in sediment. The detection limits were 1.0-7.0 μg/L, and the quantification limits were 0.50 μg/L and 5.0 μg/kg in water and sediment, respectively. The method is easy to operate with high sensitivity and reliable reproducibility, which is suitable for simultaneous determination of pyrethroid pesticides in water-sediment system.