吹扫捕集-气相色谱-质谱法同时测定土壤中27种挥发性有机物
GC-MS Determination of 27 Volatile Organic Compounds in Soil with Purge and Trap Concentrator
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摘要: 应用吹扫捕集-气相色谱-质谱法测定土壤中27种挥发性有机物的含量。选定在25 ℃条件下吹扫捕集11 min,取样品溶液5 mL于吹扫瓶中,利用Tekmar Stratum吹扫捕集器直接进样,经TR-5MS毛细管色谱柱分离,电子轰击电离(EI)全扫描和选择离子扫描检测,内标法进行定量测定。27种挥发性有机物的质量浓度与其峰面积在一定的浓度范围内呈线性关系,方法检出限(3S/N)在0.077~0.69 μg·kg-1之间。样品加标平均回收率在86.5%~117.5%之间,相对标准偏差(n=7)在1.6%~8.2%之间。Abstract: The Tekmar Stratum purge and trap concentrator was used in GC-MS determination of 27 volatile organic compounds (VOC′s) in soil. Temperature and time for purge and trap were set at 25 ℃ and 11 min respectively. Five mL. of sample solution were transferred to the purge and trap bottle and introduced into the instrument for GC-MS analysis. The VOC′s were separated on the TR-5MS capillary column and detected by the modes of full-scanning and selective ion-scanning. Internal standard was adopted in the determination. Linear relationships between peak areas and mass concentration of 27 VOC′s were obtained in definite ranges, with detection limits (3S/N) in the range of 0.077-0.69 μg·kg-1. Tests for recovery were made by addition of standard VOC′s to sample matrixes; values of recovery obtained were in the range of 86.5%-117.5%. Values of RSD′s (n=7) found for the VOC′s were in the range of 1.6%-8.2%.