GC-MS Determination of 27 Volatile Organic Compounds in Soil with Purge and Trap Concentrator

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%.