Arsenic

The metalloid arsenic belongs to the same group as the essential elements nitrogen and phosphorus. Like nitrogen and phosphorous, it forms stable oxygen bounds, but in anaerobe environment it prefers sulfur as binding partner. It forms stable penta- and trivalent compounds, whereby inorganic arsenic compounds are often found together with other chalcophilic elements like copper or iron. Organic arsenic compounds, containing one to four arsenic–carbon bounds, are widespread in biological samples. Inorganic compounds of arsenic are widely used in the metallurgy and in the semiconductor industry, organo-arsenic compounds are among others used as pesticides and herbicides.