On‐line multidimensional chromatography using packed capillary liquid chromatography and capillary gas chromatography

Abstract

Abstract The introduction of selected fractions from a liquid chromatograph into a gas chromatograph has been described; however, analyses were performed by off‐line experiments requiring collection and reinjection of the separate fractions or by on‐line procedures where disadvantageously, only a fraction of the separated peak or a well resolved component in a mixture could be introduced into a gas chromatograph. This disadvantage is overcome by the apparatus and method described in this paper, which utilizes a multidimensional chromatography system employing a high efficiency, packed capillary LC column coupled on‐line to a capillary gas chromatograph. The liquid chromatograph (so designed) can act as a highly efficient clean‐up or chemical class fractionation step prior to introduction into the gas chromatograph, significantly reducing sample preparation times in many applications. Thus minor components in a complex matrix can be determined without prior sample clean‐up, an example of which is the determination of polychlorinated biphenyls in a complex hydrocarbon matrix.