K. Imai, Yoshihiko Watanabe
Oct 1, 1981
Citations
1
Influential Citations
183
Citations
Quality indicators
Journal
Analytica Chimica Acta
Abstract
The fluorigenic reaction of proline with 7-fluoro-4-nitrobenzo-2-oxa-l,3-diazole (NBD—F) is superior, in terms of reactivity and fluorescence yield, to the reactions with the analogous 7-chloro and 7-bromo derivatives. With NBD—F, the reagent blank fluorescence can be suppressed by adjusting the medium to around pH 1 with hydrochloric acid. Many secondary amino acids can be determined by reaction with NBD—F at pH 7.5 at 70°C for 5 min and subsequent acidification to pH 1. The detection limits for proline, hydroxyproline and sarcosine are 0.08, 0.04 and 0.17 nmol ml-1, respectively. Under the same conditions, the primary amino acids, alanine, arginine and aspartic acid, are detected at 1.7, 1.7 and 3.4 nmol ml-1, respectively.