New System for the Spectrophotometric Determination of Arsenic in Water

A new method based on spectrophotometry was established for detecting the trace arsenic in water. With the existence of strong acid, the trace concentrations of arsenic after concentrating by JM-33 resin reacted with disulfoantipyl methane to form a 1:2 complex which the maximum absorption wave lied at 325nm with an apparent molar absorptivity of 1.74×10⁴1/(mol·cm). When the concentration of arsenic was between 0.02-0.5mg/l, the reaction conformed to Beer´s law. The effects of some important factors were also investigated, which showed the method was simple, selective and with high precision and accuracy. This method had been used to determine trace arsenic in the real water samples and spiked water samples with satisfactory results.