新疆干旱区土壤中苯系物的顶空气相色谱/质谱测定方法研究

Determination of benzene series in soil of arid regions by gas chromatography-mass spectrometry with headspace extraction

采用顶空气相色谱/质谱联用（HS-GC/MS）法测定干旱区土壤中苯系物（BTEX）含量，对顶空平衡温度、顶空平衡时间以及基质修正液加入量进行了分析和优化，并分析了方法的回收率和精密度。结果表明，优化顶空参数为基质修正液加入量5 mL、顶空平衡温度45 ℃、顶空平衡时间10 min；BTEX浓度与峰面积线性相关系数范围为0.996-0.999；苯，甲苯，乙苯，间、对二甲苯的平均回收率分别为81.5%、86.7%、94.4%、99.9%，相对标准偏差分别为6.62%、5.43%、4.51%、4.28%；BTEX检出限（按信噪比为3倍计）为0.076-0.204 μg/kg；定量限（按信噪比为10倍计）为0.254-0.681 μg/kg。该方法操作简单、回收率高、重现性好、灵敏度高，可为干旱区土壤中BTEX污染的监测和管理提供技术支撑。

A detection method of gas chromatography-mass spectrometry with static headspace extraction （HS- GC/MS） was established to detect benzene series （BTEX） in soil of arid regions. In order to carefully characterize the performance of the detection method, several affecting parameters were studied in detail, such as equilibrium temperature,equilibrium time and the addition amount of matrix modifying solution. The recoveries and precisions of the method were calculated. Results showed that the optimize conditions for headspace procedure were 5 mL of matrix modifying solution, equilibrium temperature 45 ℃ and equilibrium time 10 minutes. Under these conditions, correlation coefficients between BTEX concentrations and peak areas ranged 0. 996-0. 999. The average recoveries of benzene, toluene, ethylbenzene and m, p-xylene were 81.5%, 86.7%, 94.4%, 99.9% with the relative standard deviations （RSD,n=6） were 6.62%, 5.43%, 4.51% and 4.28%. The limits of detection （signal to noise ratio （S/N）= 3） were 0. 076-0. 204 μg/kg. The limits of quantification （S/N= 10） were 0. 254-0. 681 μg/kg. The method is simple, accurate, reliable and sensitive, it would provide technical support for monitoring and management of soil contaminated with BTEX in arid regions.