A simple single-reagent colorimetric method for arsenic speciation analysis: application to the Dongargarh-Kotri...

In this study, a simple colorimetric method was developed using cupric acetate monohydrate to detect and differentiate arsenic species in groundwater in the Dongargarh-Kotri region, Chhattisgarh, Central India. The method produced precipitate that was distinctly green for As(III) and blue for As(V). The method achieved a detection limit of 5.5  $\mu$ g L $_{}^{-1}$ in collected groundwater samples and required only one reagent, without any pre- or post-treatment steps. This method also offers a semi-quantitative estimation of the relative proportions of As(III) and As(V). The successful application of this method to contaminated groundwater samples demonstrates its potential as a rapid, low-cost, and field-deployable screening tool for arsenic speciation and monitoring in resource-limited regions.