水样中两种除草剂,2,4-滴及灭草松,用SPE法经Oasis HLB柱分离富集.用甲醇及甲基叔丁基醚(10+90)混合溶剂作洗提液将此两种除草剂从SPE小柱上洗脱,所得洗脱液经吹氮蒸干和用碘甲烷-二氯甲烷溶液及四丁基硫酸氢铵-氢氧化钠溶液进行柱前衍生化,所得衍生物经干燥后溶于正己烷1.0 mL中,所得溶液供GC-MS测定,所测得的峰面积值与2,4-滴或灭草松的浓度在0.1~5.0 mg·L-1范围内呈线性关系.当用200 mL水样进行分析时测得此方法的测定下限(10S/N)依次为0.02 μg·L-1及0.10 μg·L-1.

Two herbicidal chemicals,2,4-D (dichloro-phenoxy acetic acid) and bentazone in water samples were separated and enriched by SPE on Oasis HLB SPE micro-column. Mixed solvent of CH3OH and methyl-tert. butyl ether (10+90) was used to elute the 2 herbicidal chemicals from the column and the eluate was dried by N2-blowing,made up to 1.0 mL with hexane and used for GC-MS determination after pre-column derivatization with iodomethane-dichloromethane (10+90) solution and tetra-butyl-ammonium hydrogen sulfate-NaOH solution. Linear relationship between values of peak area and concentration of either 2,4-D or bentazone was obtained in the range of 0.1-5.0 mg·L-1. Values of lower limit of determination (10S/N) found were 0.02 μg·L-1 for 2,4-D and 0.10 μg·L-1 for bentazone when 200 mL of water samples were introduced.