A new system for the spectrophotometric determination of arsenic in environmental and biological samples

A new sensitive method is proposed for the determination of traces of arsen ic(III). The method involves bleaching of the pinkish red colored dye, Rhod amine-B, by the action of iodine which is released by the reaction between potassium iodate and arsenic in slightly acidic medium. The color of the dy e was measured at 553 nm. Beer's law is obeyed in the concentration range o f 0.04-0.4 mg l(-1) of arsenic. The molar absorptivity was found to be 3.24 x 10(5) l mol(-1) cm(-1). The proposed method has been successfully applie d for the determination of arsenic in various environmental and biological samples. (C) 2000 Elsevier Science B.V. All rights reserved.