Thin-layer chromatography combined with diode laser thermal vaporization inductively coupled plasma mass spectrometry for the determination of selenomethionine and selenocysteine in algae and yeast

In this work we present a simple and cost-effective approach for the determination of selenium species in algae and yeast biomass, based on a combination of thin-layer chromatography (TLC) with diode laser thermal vaporization inductively coupled plasma mass spectrometry (DLTV ICP MS). Extraction of freeze-dried biomass was performed in 4M methanesulphonic acid and the selenium species were vaporized from cellulose TLC plates employing a continuous-wave infrared diode laser with power up to 4W using a simple laboratory-built apparatus. Selenomethionine and selenocysteine were quantified with limits of detection 3 mu g L-1 in a Se-enriched microalgae Chlorella vulgaris and yeast certified reference material SELM-1. Results delivered by TLC-DLTV ICP MS were consistent with those obtained by a routine coupling of high-performance liquid chromatography (HPLC) to ICP MS. In addition, the TLC approach is capable of analyzing extract containing even undiluted crude hydrolysates that could damage HPLC columns. (C) 2017 Elsevier B.V. All rights reserved.