在线固相萃取/高效液相色谱法测定环境水样中的4种痕量邻苯二甲酸酯

摘要

建立了一种在线固相萃取/高效液相色谱测定水样中4种痕量邻苯二甲酸酯(邻苯二甲酸甲酯、邻苯二甲酸乙酯、邻苯二甲酸丁酯和邻苯二甲酸(2-乙基)己酯)的新方法.样品由外加泵注入一根固相萃取小柱上进行富集,再将富集柱切换至高效液相色谱系统中,将富集在固相萃取小柱的邻苯二甲酸酯洗脱至分析柱进行分析.在线固相萃取柱为IonPac(R)NG1保护柱芯(10 μm×4.0 mm×35 mm),分析柱为Acclaim(R)120(A)C18(5 μm×4.6 mm×150 mm),检测波长为224 nm,水样体积为15 mL.方法的线性范围为1～100μg/L,相关系数r2≥0.999 8,4种邻苯二甲酸酯的检出限(S/N=3)为0.10～0.25μg/L.方法的重复性良好,峰面积的相对标准偏差(n=5)小于2%.实际水样的加标回收率为88%～107%,表明该方法可有效用于水样中痕量邻苯二甲酸酯的快速准确分析.%A method for the simultaneous determination of four trace phthalates( PAEs), e. g. dimethyl phthalate, diethyl phthalate, dibutyl phthalate and bis (2-ethylhexyl) phthalate, in water samples was established using high performance liquid chromatography with the function of online column enrichment. After injected with an assistant pump and concentrated at the solid phase extraction cartridge, the PAEs were back-flushed to the analytical column by a six-port valve switching for detection with mobile phase. The online SPE cartridge was IonPac(R) NG1 (10 μm ×4. 0 mm ×35 mm) and the LC column was Acclaim(R) 120A C18 (5 μm ×4. 6 mm × 150 mm). The quantitation analysis of four phthalates were achieved by UV detection at 224 nm with 15 mL sample load volume. The linear ranges of four PAEs were in the range of 1 - 100 μg/L with correlation coefficients( r2 ) not less than 0. 999 8. The method detection limits( S/N=3 ) of four PAEs were between 0. 10 μg/L and 0. 25μg/L. The relative standard deviations(RSDs) of five injections of 10 μg/L working solution were less than 2％. The spiked recoveries at two matrix spiked concentrations were in the range of 88％ -107％. The results showed that the developed method was sensitive and accurate, and was suitable for the analysis of trace PAEs in water sample.