液相色谱-质谱联用法测定水-沉积物系统中四氟醚唑的残留量

建立了水-沉积物系统中四氟醚唑的液相色谱-质谱联用(LC-MS/MS)测定方法。沉积物样品依次经V(丙酮)∶V(水)=9∶1混合提取和二氯甲烷萃取后,中性氧化铝与弗罗里硅土层析柱净化,用LC-MS/MS测定;水样经二氯甲烷萃取后直接用LC-MS/MS测定。结果表明:在0.5~5μg/L或0.5~5μg/kg添加水平下,四氟醚唑在水中的平均回收率为89%~98%,相对标准偏差(RSD)为1.8%~13%,在沉积物中的平均回收率为97%~103%,RSD为6.3%~11%。该方法中四氟醚唑的最小检出量为2.0 pg,四氟醚唑在水中最低检测浓度(LOQ)为0.5μg/L,在沉积物中的LOQ为0.5μg/kg。该方法选择性好、灵敏度高、重现性好、基质干扰小,适用于水-沉积物系统中四氟醚唑残留的检测。

Determination of tetraconazole residue in water-sediment system by liquid chromatography-tandem mass spectrometry

A liquid chromatography-tandem mass spectroscopy (LC-MS/MS) method was developed for determining tetraconeazole residue in water and sediment system. The sediment samples were extracted with V(acetone):V(water)=9:1, and partitioned by dichloromethane liquid-liquid extraction, then cleaned up on neutral alumina and Florisil layer column. The water samples were prepared by dichloromethane liquid-liquid extraction and determined by LC-MS/MS. The results showed that when spiked from 0.5 to 5.0 μg/L, the average recoveries of tetraconazole in water were 89% to 98%, with relative standard deviations (RSDs) between 1.8% to 13%; when spiked from 0.5 to 5 μg/kg, the average recoveries in sediment were 97% to 103%, with RSDs between 6.3% to 11%; The limit of detection (LOD) was 2.0 pg, the limit of quantification(LOQ) in water and sediment were 0.5 μg/L and 0.5 μg/kg, respectively. The selectivity, reproducibility, accuracy and matrix effects were validated. The method was proved to be appropriate for determination of tetraconeazole residue in water and sediment system.