Abstract
A glass open tubular (capillary) column together with a nitrogen-selective detector were evaluated for the analysis of amino acids by gas chromatography. Test samples included normal and abnormal human sera and urine and several hydrolysates of pure proteins. Amino acids in the biological samples were isolated by ion exchange pretreatment and derivatized to the n-propyl, N-acetyl derivatives. Protein hydrolysates were derivatized without pretreatment. Compared with a flame ionization detector, the nitrogen-selective detector gave a sensitivity enhancement of 80x-180x for the amino acid derivatives, depending on the particular amino acid. Long-term stability of the detector was excellent. Reproducibility studies gave a long-term precision of about 6% for serum or urine samples while a precision of 5% was obtainable on a day-to-day basis when analyzing protein hydrolyzates. The experiments showed that amino acids at the picomole level could be reliably analyzed with the system. The open tubular column coated with a mixture of Carbowax 20M and Silar 5 CP and having a very thin liquid phase film gave greatly improved thermal stability compared with a previously used packed column.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.