Abstract

A SPECTROPHOTOMETRIC DETERMINATION OF SELENIUM IN FOOD SUPPLEMENTS USING 3,3DABH AS A CHROMOGENIC - WITH APPLIED MICROWAVE DIGESTION METHOD

*Katamto Lina¹, Al-Zehouri Joumaa²

ABSTRACT

For selenium (Se) determination by spectrophotometric method using 3,3' diaminobenzidine hydrochloride, microwave digestion method was used to preparing selenium samples from food supplements. The digestion method provides acid digestion of the samples in a closed vessel device using temperature control microwave heating for the selenium determination by spectrophotometric methods. Simple, sensitive and specific spectrophotometric method for the determination of selenium at trace levels was validated. spectrophotometry method using 3,3'diaminobenzidine hydrochloride was based on the formation of stable yellowcolored piazselenol complex by reaction of Se (IV) with 3, 3'diaminobenzidine hydrochloride, which is then extracted in toluene and detected spectroscopically at 420 nm. The limit of detection and quantitation of the method were found to be 0.008 μg/ml and 0.027, respectively. The optimum assay conditions were investigated and the average recovery from spiked samples was 99.7% -100.9%. Good values of precision were obtained; interday RSD% was 1.62%. The validated methods were used for estimation trace amount of Se (IV) in food supplements.

Keywords: Spectrophotometry, 3,3'Diaminobenzidine, Microwave digestion, Selenium determination, Food supplement.