METHODS AND VIAL CLOSURES FOR HEADSPACE MICROEXTRACTION UNDER VACUUM

摘要

A closure device for gas-tightly closing the opening of a vial which in use contains a liquid or solid material and sufficient headspace volume for performing off-line or automated headspace microextraction under vacuum conditions. The closure device allows for the air-evacuation of the sample container through a cavity with a seal in the presence or absence of the sample and maintains the low-pressure conditions for extended times and during handling of low or high-capacity extracting units. The methods are for off-line or automated headspace microextraction under vacuum conditions, so that the extracting unit with analytes can be conveniently analyzed by means of an analytical instrumentation such as gas chromatography, gas chromatography-mass spectrometry, liquid chromatography, and/or liquid chromatography-mass spectrometry.