engleski

THE VOLTAMMETRIC AND SPECTROPHOTOMETRIC DETERMINATION OF FOLIC ACID IN REAL SAMPLES

The study of preparation of ex situ formed bismuth film at glassy carbon electrode (BiF–GCE), with arranged homogenous structure (confirmed by scanning electron microscopy), is presented. Prepared BiF was used for the determination of folic acid (FA) by square wave cathodic stripping voltammetry. Optimized procedure and analytical performance of the prepared BiF are presented. A linear response between 0.1 μmol dm–3 and 10 μmol dm–3 together with detection limit of 0.05 nmol dm–3 were obtained. This developed method has been validated and confirmed by spectrophotometric method involves coupling reaction of folic acid and 3-aminophenol to produce an orange yellow-colored product with absorbance at 355 nm (at pH 8). Both methods were successfully applied for determination of FA in real samples (vegetables, tablets and juices) with excellent recovery ranged from 98.8-101.4 % for voltammetric method and 99.7-104.1 % for spectrophotometric method.

bismuth film electrode ; voltammetry ; spectrophotometry ; folic acid

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