固相微萃取-气相色谱-质谱联用法测定水中的32种挥发性有机物

Determination of 32 kinds of volatile organic compounds in water by solid phase microextraction-gas chromatography-mass spectrometry

目的通过优化固相微萃取(SPME)条件,确定最优实验条件,建立一种固相微萃取与气相色谱-质谱(GC-MS)联用法测定饮用水中32种挥发性有机物的方法。方法采用固相微萃取-气相色谱-质谱联用法对饮用水中的32种挥发性有机物进行测定,确定各化合物的定性定量参数,并优化固相微萃取条件,如萃取头类型、加盐量、平衡时间、萃取时间、萃取温度等,获得最优的测定条件。结果确定的最优条件为:萃取头:CAR/PDMS萃取头;加盐量:10%;平衡时间:20 min;萃取时间:30 min;萃取温度:60℃。本方法的检出限为0.005~5μg/L,在所测浓度范围内回归曲线的线性相关性良好,加标回收率为74.5%~129.5%,RSD均不大于15%(n=6)。结论该方法的前处理操作简单,具有较好的精密度和准确度,且检出限远低于国家限定标准,可对饮用水中多种挥发性有机物同时进行分析。

ABSTRACT:Objective To establish a method for determination of 32 kinds of volatile organic compounds in drinking water using solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) based on optimal conditions of SPME. Methods SPME-GS-MS were used on qualitative and quantitative determination of 32 kinds of volatile organic compounds. SPME conditions including SPME coating types, NaCl concentration, incubation time, extraction time and extraction temperature were optimized. Results The optimized conditions were as follows: the best fiber coating was CAR/PDMS;NaCl concentration was 10%;incubation time was 20 min;extraction time was 30 min;and extraction temperature was 60℃. The detection limits of this method fell in the range of 0.005~5 μg/L and there were good linearity relations between the compounds and instrumental responds. RSDs were all no more than 15%(n=6), recovery rates were between 74.5%and 129.5%. Conclusion This method is simple. It has a good precision and accuracy, and its detection limits are far lower than that in the national standards, so it can be applied to the analysis of the volatile organic compounds in drinking water.