Selective spectrophotmetric determination of oxyphenbutazone using a chelate forming reaction

A selective spectroPhotometric method for the determination of oxyphenbutazone is described. The method is based on nitrosation reaction and simultaneous fornation of copper (II) or cobalt (II) chelate of the nitrosoderivative. The formed chelates are extractable with organic solvents giving yellow solutions whose absorbance are proportional to the concentration of oxyphenbutazone. In addition, the chelate extracts, upon treatment with diethyldithiocarbanate develop an additional indirect method of high selectivity for determining oxyphenbutazone. The developed methods are highly accurate and comparable with an official method. © 1985, Taylor & Francis Group, LLC. All rights reserved.