Assessment of thiol compounds from garlic by automated headspace derivatized in-needle-NTD-GC-MS and derivatized in-fiber-SPME-GC-MS.

This study investigates the analysis of thiol compounds using a needle trap device (HS-NTD) and solid-phase microextraction (HS-SPME) derivatized headspace techniques coupled to GC-MS. Thiol compounds and their outgassed products are particularly difficult to monitor in foodstuffs. It was found that with in-needle and in-fiber derivatization, using the derivatization agent N-phenylmaleimide, it was possible to enhance the selectivity toward thiol, which allowed the quantitation of butanethiol, ethanethiol, methanethiol, and propanethiol compounds found in fresh garlic.