Dual wave β-correction spectrophotometry for trace determination and chemical speciation of As(III)/As(V) in water

Abstract

A facile and low-cost strategy for trace determination and chemical speciation of As(III) and As(V) has been developed via dual wave β-correction spectrophotometry. As(III) in the presence of chromogenic reagent zincon forms a purple colored arsenic-zincon complex. When recorded at λmax = 592 nm, a wide linear dynamic range (0.1–4.5 μg/mL) was obtained. The limit of detection (LOD) of the developed method was 10 ng mL−1. As5+ was also determined after reduction to As(III) with Na2SO3 in acidic solution. The method was applied for the determination as well as chemical speciation of arsenic in water samples. Results compared successfully with the official reference method inductively coupled plasma- mass spectrometry (lCP-OES). The developed method has a unique advantage to be applied directly towards quantitatively determination of representative analyze in a variety of samples due to simple instrumentation, no additional expensive material requirement and rapid response time.