Degradation product of the chemical warfare agent, VX, q.v. Prepn as sodium salt: V. S. Abramov, M. N. Morozova, J. Gen. Chem. USSR 22, 315 (1952). Capillary electrophoretic determn in soils: A.-E. F. Nassar et al., Anal. Chem. 71, 1285 (1999). Determn in human urine samples after exposure to VX: M. Minami et al., J. Toxicol. Sci. 23, Suppl. II 250 (1998).