Rapid screening of volatile compounds in edible plants by direct chromatographic analysis

A method based on the use of the on-line coupling of two programmed temperature vaporizers (PTVs) is proposed to perform the concentration step required prior to the gas chromatographic determination of volatile compounds in edible plants. The reported procedure does not demand a previous sample handling stage whilst allowing the rapid and reliable screening of plant materials to be performed. The matrix to be analysed is directly introduced into the PTV of a gas chromatograph, thus avoiding the risk of losses and contamination typically observed when external concentration techniques are applied. The analytes in the vapour phase are swept from the matrix and then retained onto a suitable adsorbent material placed inside the second PTV injector. The described set-up allows the simple and rapid performance of the experimental work as the overall analysis of naturally occurring compounds with potential application as food ingredients can be performed in less than 1 h.