The method describes how to determine the arsenic content of water using atomic absorption spectrometry. Arsenic is present in the form of arsenic(III) or arsenic(V), depending upon the redox potential and pH of the water.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
The hydride technique is used to determine the concentration of arsenic ions in the water sample. In this process, arsenic ions are reduced by sodium tetrahydroborate in an acidic medium to arsine. This compound is then transferred using an inert gas into a heated quartz cuvette, is pyrolyzed and measured using AAS.
The absorbance is determined at a wavelength of 193.7 nm, and the arsenic concentration is calculated using a reference curve.