Combined solvent extraction-purge and trap method for the determination of volatile organic compounds in sediments

Abstract

A method involving methanol solvent extraction (SE) and purge and trap (PT) was evaluated for the determination of chlorinated volatile organic compounds (VOC) in sediments. The method was tested by means of standard solutions encompassing twenty chlorinated compounds with boiling points ranging between 24 and 150°C (at 1 atm = 101 325 Pa). Detection limits (0.05-0.4 μg/g), linearity ranges and recoveries (only 1% average losses by glassware manipulation and 7.5% losses after water sediment suspension with standards and methanol extraction) show the suitability of the method for the determination of chlorinated VOC in environmental samples. A specific advantage of this method is the possibility of storage of the VOC methanol extracts for long periods of time at −20°C without significant alteration of the quantitative results. In the conditions of the study, the average recovery of individual VOCs after storage for 50 days was 89%.