A SIMPLE SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF ARSENIC IN INDUSTRIAL AND ENVIRONMENTAL SAMPLES USING 5- METHYLTHIOPHENE – 2-CARBOXALDEHYDE ETHYLENEDIAMINE (MTCED)

K. Deepa, Himagirish Kumar S., Y. Harinath, N. V. V. Jyothi* and Y. Lingappa

ABSTRACT

5-methylthiophene– 2-carboxaldehyde ethylenediamine (MTCED) has been proposed as new analytical reagent for the direct non-extractive spectrophotometric determination of Arsenic. The reagent reacts with arsenic in acidic medium (pH 4.0, Sodium acetate- acetic acid buffer) to form light greenish yellow colored 1:1 (M:L). The colour reactions are instaneous and the maximum absorbance was obtained at 395 nm and remains constant for over 5 h. The molar absorptivity and Sandell’s sensitivity of MTCED found to be 5.99 x 104 L mol-1cm-1 and 0.0016 μgcm-2 of As (III) respectively. The system obeys Beer’s law in the range of 0.129 - 2.668 μg/ml of As (III). Since MTCED method is more sensitive it was applied for determination of Arsenic in some environmental water samples.

Keywords: Spectrophotometry, Arsenic determination, MTCED, Environmental samples.