Determination of airborne methamphetamine via capillary microextraction of volatiles (CMV) with on-sorbent derivatisation using o-pentafluorobenzyl chloroformate

Abstract

Capillary microextraction of volatiles (CMV), a high surface area sampling technique, was combined with on-sorbent derivatisation to develop a sensitive alternative to dynamic solid phase microextraction (SPME) sampling for airborne methamphetamine. CMV devices pre-loaded with pentafluorobenzyl chloroformate were used to sample methamphetamine vapour at a concentration of 4.2 μg m−3 for periods of 2–10 min and the retained analytes analysed using gas chromatography-mass spectrometry (GC–MS). The methamphetamine pentafluorobenzyl carbamate derivative formed under ambient conditions.This CMV technique showed over 60 times greater sensitivity compared to dynamic solid phase microextraction (SPME) sampling for airborne methamphetamine, and the CMV devices could be stored for up to 5 days post-sampling, without loss of analyte. The inter-device variability (∼15%) was the same for the CMV devices with or without prior derivatisation, however the intra-device reproducibility was under 7% when derivatised.