In-tube solid-phase microextraction sampler for long-term storage

Capillary extractors are proposed as samplers-preconcentrators to overcome losses of volatile organic compounds found using "classical" solid-phase microextraction fiber-holder samplers. A set of equal-size extractors was used to extract in-tube an aqueous solution of benzene, toluene, ethylbenzene and xylenes (BTEX) at 146 ppb. After storage for 6-30 days at 0-4 degrees C (or -15 degrees C) GC analyses were carried out to study BTEX recovery. Results demonstrated that sample preservation was very good: recovery was higher than 98% after 6 days, and more than 95% after 30 days. Capillary extractors, due to their high performance in preserving sample integrity, represent a real breakthrough for on-site sampling of volatile compounds by solid-phase pre-concentration techniques.