Absorbents as packing materials in on-line coupling of reversed phase liquid chromatography and gas chromatography via a programmed temperature vaporizer

A method based on the use of absorbents as packing materials in the interface of the direct coupling between reversed phase liquid chromatography and gas chromatography (RPLC–GC) is proposed. To that end, a comparative study on different adsorbents and absorbents was carried out. Specifically, Tenax TA and Gaschrom were used as adsorbents while polydimethylsiloxane and poly(50% phenyl:50% methylsiloxane) were the absorbents tested. Some experimental variables involved in the solvent elimination were separately optimised for adsorbent and absorbent materials. Relative standard deviations (RSD) lower than 10% were achieved in all cases but the use of absorbents showed interesting advantages with respect to adsorbents, namely a simpler performance of the experimental work, which facilitates the sample preparation step and the subsequent gas chromatographic analysis to be performed.