Determination of volatile chlorinated hydrocarbons in air and water with solid-phase microextraction

Abstract

A method for sampling volatile chlorinated hydrocarbons in either gaseous or aqueous samples using solid-phase microextraction (SPME) is presented. In the liquid phase, method limits of detection of 1–130 ng l^–1 can be achieved with an electron-capture detector. The method is linear over at least 2–4 orders of magnitude and has a relative standard deviation of 1–5%. In the gaseous phase, the method has limits of detection in the parts per trillion (v/v) range when used with an electron-capture detector. The linear range is at least two orders of magnitude and the relative standard deviation is 1–7%. Sample preparation times range from 10 min for gaseous samples to 20 min for liquid samples. The method is comparable to US Environmental Protection Agency (EPA) methods 502.2 and TO-14. The precision of the technique is relatively independent of the number of injections made per container. Samples can be stored for up to 20 min on the fibre if they are capped and refrigerated. The amount absorbed by the fibre decreases with increasing temperature and increasing humidity.