Determination of Arsenic in Environment by Spectrophotometric Technique using Hydroxamic Acids

Abstract

A simple, rapid, stable and sensitive direct visible spectrophotometric method has been developed for the determination of trace amount of arsenic in environmental samples of Bhopal city using N-PBHA, N-p- ClPBHA and N-p-ClPCHA, Arsenic (III) reacts with different hydroxamic acids and forms light pink to violet colored complex in acidic medium which were extracted in n- hexane. The calibration graph was linear over the concentrationrange of 0.0003786-0.004164, 0.003786-0.06057 and 0.003786-0.04921µgml -1 for N-Phenyl- benzo-hydroxamic acid (N-PBHA), N-p- Chloro-phenyl- benzo-hydroxamic acid (N-p-ClPBHA) and N-p- Chloro-phenyl-cinnamohydroxamic acid (N-p-ClPCHA), respectively. The molar absorptivities were found to be 2.892x10 5 , 1.5973x10 4 and 2.0238x10 4 L mol -1 cm -1 for the three hydroxamic acids. The optimum reaction