The method describes how to determine the selenium content of water using atomic absorption spectrometry. Selenium is a by-product of coal combustion and of refining sulfurous ores. The presumption is that these emissions result in the accumulation of selenium in agricultural and unutilized lands, where the plants on these lands are able to utilize the selenium. In drinking water, selenium is found in very low concentrations, in the lower ppb range.
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 selenium ions in the water sample. In this process, selenium ions are reduced by sodium tetrahydroborate in an acidic medium. This compound is then transferred using an inert gas into a heated quartz cuvette, where it is pyrolyzed and measured using AAS.