Development and Applications of a Sampling Device Using Micro Coil for GC

Abstract

A simple and rapid procedure was developed for the gas chromatographic analysis of vegetable oil involved in a crime. This procedure was performed using a syringe-type device. This device consists of a stainless-steel micro coil that is attached to a retractable plunger wire, which fits inside of a syringe needle housing. This device using a micro coil was called MCSD (Micro Coil Sampling Device), and was used as follows. In the first step, sampling was accomplished by dipping the end of the micro coil in a trace amount of oil, which was drawn into the micro coil by capillary action, and introducing it into the injection port of a gas chromatograph. Unsaponifiable constituents, such as sterols, could be detected by thermal desorption from the micro coil in the injection port. After thermal desorption, a GC/MS measurement of unsaponifiable constituents, a trimethylphenylammonium hydroxide solution was added to the remaining acylglycerols on a micro coil. Then, the micro coil was introduced into the injection port of the gas chromatograph to observe the fatty acid components by thermochemolysis with an esterification reagent. This procedure used MCSD could serve as a useful and powerful tool for forensic inspection of vegetable oil.