提出了气相色谱法测定水中10种不同极性有机磷农药含量的方法。取水样50 mL,用盐酸(1+1)溶液调节其酸度至pH 3~5,过LiChrolut EN Merck固相萃取小柱,先后用丙酮2 mL、乙腈2 mL、二氯甲烷2 mL作为洗脱剂进行洗脱,再经石墨化炭黑柱净化。用乙腈及丙酮各3 mL淋洗炭黑柱,洗脱液供GC分析。采用DB 17毛细管色谱柱分离,火焰热离子检测器测定。10种有机磷农药的线性范围均在0.1~4.0 μg·L-1之间,方法的检出限(3s)在0.10~0.30 μg·L-1之间。方法用于测定水样中有机磷农药的含量,并进行加标回收试验,回收率在78.8%~102%之间,测定值的相对标准偏差(n=7)在1.7%~7.4%之间。

A method of GC for the determination of 10 organophosphorus pesticides with different polarity in water was proposed. Acidity of water sample (50 mL) was adjusted to pH 3-5 with HCl (1+1) solution, and the sample solution was extracted on LiChrolut EN Merck solid phase extraction column (SPE). Then organophosphorus pesticides on the SPE column were eluted in succession with acetone (2 mL), acetonitrile (2 mL) and CH2Cl2 (2 mL); and the eluate obtained was purified on graphitized carbon black column. The carbon black column was eluted with 3 mL each of acetonitrile and acetone, and the eluate was used for GC analysis. DB17 capillary column was used for separation, and FTD was used for determination. Linearity ranges for the 10 organophosphorus pesticides were found to be same between of 0.1-4.0 μg·L-1, with detection limit (3s) in the range of 0.10-0.30 μg·L-1. The proposed method was applied to the determination of organophosphorus pesticides in water sample, giving values of recovery by standard addition method in the range of 78.8%-102% with RSD′s (n=7) in the range of 1.7%-7.4%.