采用固相萃取-气相色谱法测定水中唑酮草酯的残留

以C18固相萃取法(C18-SPE)和带有电子捕获检测器的气相色谱仪(GC-ECD)为检测手段,建立了水体中唑酮草酯的残留检测方法。通过对淋洗液体积、水样体积和水样pH值等条件的优化,确定水样体积500 mL、pH 7.0、淋洗液乙酸乙酯(3 mL)为最佳固相萃取条件。该方法在0.1、0.5和2.0 μg/L 3个添加水平的回收率为81.45%~108.7%,相对标准偏差(RSD)为0.74% ~1.5%,方法检出限为0.02 μg/L。应用该方法对两个环境样本(自来水和河水)进行检测,均未检出唑酮草酯的残留。对自来水和河水样本进行0.5 μg/L的添加回收实验,其平均回收率分别为93.8%和79.9%, RSD分别为1.3% 和8.0%,表明该方法适用于水体中唑酮草酯的残留检测。

Solid-phase Extraction and Gas Chromatography forDetermination of Carfentrazone-ethyl Residue in Water

The solid-phase extraction (SPE) and gas chromatography connected with electron-capture detector (GC-ECD) was used for determination of carfentrazone-ethyl residue in water.Several key parameters that influence the SPE performance were studied.The results showed that good recovery was obtained using 3 mL ethyl-acetate as the eluent and the sample volume was 500 mL at pH 7.0.The fortified recovery of carfentrazone-ethyl at concentration of 0.1,0.5 and 2.0 μg/L was in the range of 81.45%~108.7%,with the RSD of 0.74%~1.5%.The limit of detection of carfentrazone-ethyl in water was 0.02 μg/L.The established method was applied to detect two environmental water samples (tap water and river water) and the results showed that there was no detectable carfentrazone-ethyl residue in the samples.Furthermore,the fortified recovery of carfentrazone-ethyl in the tap water and river water at 0.5 μg/L was 93.8% and 79.9%,with RSD of 1.3% and 8.0% respectively.The results showed that this method was suitable for detecting carfentrazone-ethyl in environmental water samples.