Selenium determination in various vegetable samples by spectrophotometry

Abstract

A rapid, highly sensitive and selective spectrophotometric method for the determination of traces of selenium (IV) is described. The method is based on oxidation of 4-aminopyridine by selenium (IV) followed by coupling reaction with N-(1-naphthalene-1-yl)ethane-1,2-diamine dihydrochloride (NEDA) in acid medium to give purple colored derivative with λmax 560 nm and is stable for more than 15 days at 35 °C. Beer's law is obeyed for selenium (IV) in the concentration range of 1.0-21 μg ml-1 at the wavelength of maximum absorption. The optimum reaction conditions and other analytical parameters were investigated to enhance the sensitivity of the present method. The detailed study of various interferences made the method more selective. The proposed method was successfully applied to the analysis of selenium in various vegetable samples. The results obtained were agreed with the reported methods at the 95% confidence level. The performance of proposed method was evaluated in terms of Student's t-test and Variance ratio f-test which indicates the significance of proposed method over reported method. © 2006 Elsevier Ltd. All rights reserved.