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

A new sensitive method is proposed for the determination of traces of arsenic(III). The method involves bleaching of the pinkish red colored dye, Rhodamine-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 dye was measured at 553 nm. Beer’s law is obeyed in the concentration range of 0.04–0.4 mg l−1 of arsenic. The molar absorptivity was found to be 3.24 × 105 l mol−1 cm−1. The proposed method has been successfully applied for the determination of arsenic in various environmental and biological samples.