Premium
Flow injection chemiluminescence determination of vitamin B 12 using on‐line UV‐persulfate photooxidation and charge coupled device detection
Author(s) -
Murillo Pulgarín José A.,
García Bermejo Luisa F.,
Nieves Sánchez García M.
Publication year - 2011
Publication title -
luminescence
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 45
eISSN - 1522-7243
pISSN - 1522-7235
DOI - 10.1002/bio.1266
Subject(s) - chemiluminescence , persulfate , chemistry , luminol , hydrogen peroxide , detection limit , cobalt , chromatography , catalysis , inorganic chemistry , organic chemistry
A sensitive chemiluminescence method for vitamin B 12 using a charge‐coupled device (CCD) photodetector combined with on‐line UV‐persulfate oxidation in a simple continuous flow system has been developed. The principle for the determination of vitamin B 12 is based on the enhancive effect of cobalt (II) on the chemiluminescence reaction between luminol and percarbonate in alkaline medium. In addition, percarbonate has been investigated and proposed as a powerful source of hydrogen peroxide as oxidant agent in this chemiluminescence reaction. The digestion of vitamin B 12 to release the cobalt (II) is reached by UV irradiation treatment in a persulfate medium. The CCD detector, directly connected to the flow cell, is used with the continuous flow manifold to obtain the full spectral characteristics of cobalt (II) catalyzed luminol–percarbonate reaction. The vitamin B 12 oxidation process and chemical conditions for the chemiluminescence reaction were investigated and optimized. The increment of the emission intensity was proportional to the concentration of vitamin B 12 , giving a second‐order calibration graph over the cobalt (II) concentration range from 10 to 5000 μg L −1 ( r 2 = 0.9985) with a detection limit of 9.3 μg L −1 . The proposed method was applied to the determination of vitamin B 12 in different kinds of pharmaceuticals. Copyright © 2011 John Wiley & Sons, Ltd.