REACTION-FREQUENCY METRIC METHOD - A NEW ANALYTICAL TECHNIQUE FOR DETERMINATION OF SUBMICROMOLAR CONCENTRATION LEVELS OF VITAMIN-C

Authors
NIE LH TAN SL YAO SZ
Citation
Lh. Nie et al., REACTION-FREQUENCY METRIC METHOD - A NEW ANALYTICAL TECHNIQUE FOR DETERMINATION OF SUBMICROMOLAR CONCENTRATION LEVELS OF VITAMIN-C, Journal of pharmaceutical sciences, 82(5), 1993, pp. 457-460
Citations number
7
Categorie Soggetti
Chemistry,"Pharmacology & Pharmacy
Journal title
Journal of pharmaceutical sciences → ACNP
ISSN journal
00223549
Volume
82
Issue
5
Year of publication
1993
Pages
457 - 460
Database
ISI
SICI code
0022-3549(1993)82:5<457:RMM-AN>2.0.ZU;2-O
Abstract
A new analytical technique for the assay of pharmaceutical substances at low concentration levels has been proposed and applied to the deter mination of vitamin C as an example of its application. It is based on the chemical reaction of vitamin C with iodine in a sodium citrate-hy drochloric acid medium, followed by measurement of the frequency chang e of a silver-plated piezoelectric quartz crystal. The frequency chang e is proportional to the vitamin C concentration from 2 X 10(-7) to 4 x 10(-6) M. The method was applied to the assay of vitamin C in pharma ceutical preparations.