SPECTROPHOTOMETRIC DETERMINATION OF SELENIUM IN WATER, SOIL SAMPLES USING 2­ACETYL­5­CHLORO THIOPHENE, PHENYLENEDIAMINE

Abstract

Analytical application of 2‐acetyl‐5‐chlorothiophene, phenylenediamine (ACTPDA) is described for the direct non‐extractive
spectrophotometric determination of Selenium. The synthesized and characterized using IR and NMR spectral data .The reagents react with
Selenium, in acidic medium (pH 6.0., sodium acetate‐acetic acid buffer) to form yellow colored1:2 (M: L) complexes. The colour reactions are
instantaneous and absorbance values remain constant for over 24 h. The molar absorptivity and Sandell’s sensitivity of ACTPDA methods are found
to be 1.002 X 10 4 L mol‐1 cm‐1 8.66 X10‐4 µg cm‐2 ,0.075 µgmL‐1 and0.025 µgmL‐1 of SeIV respectively. The systems obey Beer’s law in the range of 2.5
‐10 µg/ml of SeIV. Since ACTPDA method is more sensitive it was applied for the determination of selenium in water and soil samples.