Selective and Sensitive Determination of Protein and Non-Protein Amino Acids by Capillary Gas Chromatography with Nitrogen–Phosphorus Selective Detection

✍ Scribed by Hiroyuki Kataoka

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 156 KB
• Volume: 11
• Category: Article
• ISSN: 0269-3879
• DOI: 10.1002/(sici)1099-0801(199705)11:3<154::aid-bmc652>3.0.co;2-g

✦ Synopsis

A selective and sensitive method for the determination of protein and non-protein amino acids by capillary gas chromatography (GC) has been developed. The amino acids were converted into their N(O,S)-isobutoxycarbonyl methyl ester derivatives and measured by GC with nitrogen-phosphorus selective detection using a DB-17ht capillary column. Using this method, the derivatives of the 21 protein amino acids and the 33 non-protein amino acids provided excellent NPD responses, and were quantitatively and reproducibly resolved within 28 min. The detection limits of these amino acids were 6-150 pg per injection. The calibration curves were linear in the range 0.02-2 g for each amino acid, the correlation coefficients being above 0.990. This method was successfully applied to small urine samples without prior clean-up, and analysed without any influence from coexisting substances. Overall recoveries of amino acids added to urine sample were 83-108%. The analytical results of free amino acid contents in urine samples of normal subjects are presented.