吸附剂提取-GC/MS法测定农田水中的8种常用农药

Absorbent-Extracting GC-MS Method for Determination of 8 Formal Pesticides in Farmland Water

建立气相色谱-质谱(GC-MS)法同时检测农田水中8种常用农药(毒死蜱、乙酰甲胺磷、丙溴磷、高效氯氟氰菊酯、溴氰菊酯、氯氰菊酯、噻虫嗪、氟虫氰)的方法。农田水样品经吸附剂提取、净化等预处理,用乙腈-冰乙酸(9︰1, V/V)作为提取液,无水硫酸镁和十八烷基硅烷(C18)粉末净化,净化液用丙酮定容至1.0 mL, 0.22μm滤膜过滤,经气相色谱仪-质谱联用仪定性定量检测。结果表明, 8种常用农药在0.05~25μg/m L范围内线性关系良好, R2均小于0.995;检出限在0.008~0.020 mg/kg之间,加标回收率(低点0.05 mg/kg、中点1.0 mg/kg、高点10.0 mg/kg)均在83.6%~105.5%之间;重复性RSD为3.42%~4.92%(n=6),精密度RSD为1.69%~2.64%(n=6)。该方法具有前处理提取快速、检出限低、检测结果准确等优点,可用于农田水中常用农药的监测。

A GC-MS method for determination of 8 formal pesticides(chlorpyrifos,acephate,profenofos,lambda-cyhalothrin,deltamethrin,chlorpyrifos,thiamethoxam,and cyanogen fluoride)in farmland water was established.Farmland water samples were extracted by absorbent and purified.Acetontrile-glacial acetic acid(9︰1,V/V)was selected as extraction solution,and anhydrous magnesium sulfate and ocradecyl silane(C18)were used for purifying.The purified solution was diluted with acetone to1.0 mL and filtered by 0.22μm filter membrane.Samples were analyzed quantitatively by gas chromatography coupled with mass spectrometry(GC-MS).The results showed that concentration of 8 pesticides showed good linear relationships in the range 0.05-25μg/mL,and the correlation coefficients were all above 0.995.Detection limits were between 0.008 mg/kg and0.020 mg/kg,and the recoveries(low level 0.05 mg/kg,medium level 1.0 mg/kg,and high level 10.0 mg/kg)were ranged from 83.6%to 105.5%;The relative standard deviation(RSD)of repeatability for 8 formal pesticides was 3.42%-4.92%.The relative standard deviation of precision(n=6)was 1.69%-2.64%.This method was proved to have quick pre-treated,low detection and with accuracy and reliable results,which could apply to determine formal pesticides in farmland water.