Capillary gas chromatography of protein amino acids as N(O,S)-isobutyloxycarbonyl tert.-butyldimethylsilyl derivatives in aqueous samples
1992; Elsevier BV; Volume: 605; Issue: 2 Linguagem: Inglês
10.1016/0021-9673(92)85242-l
ISSN1873-3778
AutoresKyoung‐Rae Kim, Jung‐Han Kim, Chang-Hwan Oh, Tom J. Mabry,
Tópico(s)Molecular Sensors and Ion Detection
ResumoA method for the quantitative determination of the nineteen protein amino acids by gas chromatography is described. The amino acids were allowed to react with isobutyl chloroformate in a basic aqueous medium and the resulting N(O,S)-isobutyloxycarbonyl (isoBOC) amino acids were extracted into an organic solvent after acidification. The isolated N(O,S)-isoBOC amino acids were then converted to stable tert.-butyldimethylsilyl (TBDMS) derivatives, which were analyzed by gas chromatography and gas chromatography—mass spectrometry. The characteristic [M - 57], [M - 113], [M - 159], [M - 174], etc. ions in the mass spectra of N(O,S)-isoBOC TBDMS derivatives enabled rapid confirmation of the amino acids. Temperature-programmed retention index (I) sets measured on DB-5 and DB-17 capillary columns were characteristic of each amino acid thus being useful for the quick identification by computer I matching. The overall extraction and derivatization yields of the amino acids studied were linear in the range of 20–80 ωg.
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