Factorial analysis optimization of a Diltiazem kinetic spectrophotometric quantification method

• Type: Article in International Scientific Journal
• Date: 2008

Authors

leitao, jmm (Author) Other; da silva, jcge (Author) FCUP

Journal

Title: Analytica Chimica Acta

Vol. 609

Pages: 1-12

ISSN: 0003-2670

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 15 Citations

Scopus - 14 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-004-1FZ

DOI: 10.1016/j.aca.2007.12.020

Abstract (EN): A Diltiazem kinetic spectrophotometric method was optimized by factorial analysis. The experimental method is based on a two-stage reaction of Diltiazem with hydroxylamine and a ferric salt: in the first stage there is a hydroxamic acid formation; and, in the second stage there is a red colour complex ferric hydroxamate formation. The variables under investigation were: solvent; hydroxylamine, sodium hydroxide and ammonium ferric sulphate concentrations; volume of perchloric acid; and, temperature. The responses of the reactional system were the maximum absorbance, the wavelength and the reaction time at maximum absorbance. Experimental design methodologies were used in the optimization. Fractional and full factorial designs followed by optimization Box-Behnken and central composite experimental designs were used. The observed optimum conditions were: methanol as reaction solvent; hydroxylamine concentration of 9.375%; sodium hydroxide concentration of 18.750%; ferric reagent concentration of 2.000%; minimum volume of perchloric acid to neutralize the sodium hydroxide; and, room temperature as reaction temperature. With this set of experimental conditions a reaction time of 10.5 s with maximum colour development at 512 nm wavelength was achieved.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12