Selective and sensitive determination of protein and non-protein amino acids by capillary gas chromatography with nitrogen-phosphorus selective detection.
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 micrograms 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.
Kataoka
H
H
Faculty of Pharmaceutical Sciences, Okayama University, Japan.
D000596:Amino Acids / Q000032:analysis* / Q000652:urine; D002849:Chromatography, Gas / Q000379:methods*; D006801:Humans; D016014:Linear Models; D009584:Nitrogen; D010758:Phosphorus; D015203:Reproducibility of Results
D000596:Amino Acids; D010758:Phosphorus; D009584:Nitrogen