水中25种挥发性有机物的固相微萃取-气相色谱-质谱测定法

Determination of 25 volatile organic compounds in water by solid phase microextraction-gas chromatography-mass spectrometry

目的建立了水中25种挥发性有机物(volatile organic compounds,VOCs)的固相微萃取-气相色谱-质谱(GC-MS)测定方法。方法取10 ml水样进行固相微萃取,加入4 g氯化钠,采用CAR-PDMS涂层的纤维头(85μm),于40℃萃取15 min,萃取速度为20 mm/s,解析时间3 min,经TG-5ms色谱柱(30 m×0.25 mm,0.25μm)分离后,进行气相色谱质谱法测定。结果 24种VOCs在1.0~20.0μg/L(环氧氯丙烷在5.0~100μg/L)范围内,该方法所得回归方程均具有较好的线性关系,r值为0.996 7~0.999 6。该方法的检出限为0.010~1.0μg/L,定量下限为0.030~3.0μg/L,平均回收率为90.2%~108.5%,RSD为0.6%~8.3%。结论该方法操作简便、快捷,无需使用有机溶剂,且定性定量准确,适用于实际水样中25种VOCs的同时测定。

Objective To establish a method for the determination of 25 volatile organic compounds(VOCs) in water by solid phase microextraction coupled with gas chromatography-mass spectrometry(GC-MS). Methods The water samples(10 ml)were extracted by CAR-PDMS fibre head(85 μm) at 40 ℃ for 15 min and 4 g sodium chloride,the extraction speed was20 mm/s and the resolution time was 3 min. After separation by TG-5 ms column(30 m×0.25 mm,0.25 μm),the 25 volatile organic compounds were analyzed by gas chromatography-mass spectrometry. Results The calibration curves of 24 volatile organic compounds showed good linear relationships in the range of 1.0-20.0 μg/L(the epichlorohydrin was in the range of5.0-100.0 μg/L),the correlation coefficients were 0.996 7-0.999 6. The limits of detection were 0.010-1.0 μg/L,the limits of quantitation were 0.030-3.0 μg/L respectively. The average recovery rates were 90.2%-108.5% and the RSDs were 0.6%-8.3%. Conclusion The method is simple,rapid,without the use of organic solvents,and accurate in qualitative and quantitative analysis. It is suitable for the simultaneous determination of 25 VOCs in actual water samples.