标题：Quantitative Determination of Selenium and Development of Chemical Sensing Indicator Plates via New Synthesized Dye and its Application in Water and Plant Samples
摘要：A selective, simple, inexpensive and a new reagent for determination of selenium is proposed. This method is based on oxidation of hydroxylamine hydrochloride with selenite ions to nitrous acid, which in turn diazotizes sulfanilic acid which subsequently couples with NEDA to form magenta colored azo dye. The dye thus formed shows a maximum absorbance at 550 nm. The method obeys Beers law in the range of 0.05 to 0.26 ppm of Se. Its molar absorptivity, Sandells sensitivity, standard deviation and relative standard deviation were found 9.04x103, 8.73x10-3, 0.002, and 0.87% respectively. All the reaction parameters have been optimized. Interferences between the azo reaction and non targeted ions often present in environmental samples were investigated. The method has been successfully applied to the analysis of waste water and plant material. Chemical sensing strips were also been prepared and were successfully applied for detection of selenium in air and semi quantitative determination in water. The advantages of method are its high sensitivity, reproducibility, and the fact that measurement is simple, rapid and low cost.
