ABSTRACT
Oxyhalides refer to anions containing one halogen atom and one or more oxygen atom(s) with a single negative charge and include perchlorate ( 4ClO−), chlorate ( 3ClO−), chlorite ( 2ClO−), and hypochlorite (ClO−) and similar oxo anions of bromine and iodine, such as perbromate ( 4BrO−), bromate ( 3BrO−), or iodate ( 4IO−). Fluorine, however, does not form such oxy uoride anions. A few oxyhalide anions, especially, the disinfection by-products, perchlorate, chlorate, chlorite, and bromate are found in the ground-and surface waters in the United States. Perchlorate salts are used in rocket propellants and explosives. Chlorine dioxide, ClO2, and hypochlorite salts of sodium and calcium are used in water treatment to kill bacterias. Oxyhalides are strong oxidizing agents. Perchlorate and other oxyhalide anions are suspected carcinogens and are globally regulated. e U.S. EPA has promulgated analytical methods to measure oxyhalides that are well below their maximum contaminant levels in the drinking waters for compliance monitoring.
