取水样25 mL,加入无水硫酸钠3.0 g,加入环己烷2.0 mL,振荡萃取3 min。移取萃取了邻苯二甲酸二(2-乙基己基)酯(DEHP)的上层有机相2.0 μL注入HP-5毛细管柱(30 m×0.32 mm,0.25 μm)色谱分离后进行质谱测定。DEHP的质量浓度在50.0 μg·L-1以内与其峰面积呈线性关系,方法的检出限(3S/N)为0.052 μg·L-1。分析了早、中、晚不同时间的天津市自来水,并用标准加入法做回收试验,测得回收率在97.0%~109.4%之间,测定值的相对标准偏差(n=6)均小于2.5%。

3.0g of anhydrous Na2SO4 was added to 25 mL of the water sample, which was then extracted by shaking for 3 min with 2.0 mL of cyclohexane. 2.0 μL of the supernatant organic phase containing di-(2-ethylhexyl)-phthalate (DEHP), was introduced into the HP-5 (30 m×0.32 mm, 0.25 μm) capillary chromatographic column, separated and determined by MS. Linear relationship between values of peak area and mass concentration of DEHP was obtained in the range within 50.0 μg·L-1, with detection limit (3S/N) of 0.052 μg·L-1. Three samples of the tap water collected in the morning, noon and night, were analysed by this method, and recovery was tested by standard addition method, giving values of recovery in the range of 97.0%-109.4%, with RSD′s (n=6) less than 2.5%.