Visual detection of arsenic using hydride generation followed by reaction with silver bis(2-ethylhexyl)dithiocarbamate retained in a support filter.

In this study, a simple and effective method for the detection of trace amounts of arsenic in water samples was developed. Arsenic hydride generated by the reduction of a water sample was passed through a sensing filter retaining silver bis(2-ethylhexyl)dithiocarbamate complex. The original yellow color of the filter immediately turned reddish violet. The difference of color was observed by a reflection spectrophotometer. Sensing filters made of glass fiber gave the highest sensitivity. Addition of low volatile amines effectively stabilized the performance of the sensing filter. Common anions including phosphate ion did not interfere with the arsenic detection. Visual detection of 10 μg dm(-3) was achieved in φ10 mm filter area using 60 cm(3) of sample solution.