The use of cetylpyridinium bromide, a cationic surfactant, added as a modifier to an aqueous acetonitrile mobile phase allowed good separation of the inorganic anions iodate, bromate, bromide, nitrite, nitrate, iodide and thiocyanate on a reversed-phase high-performance liquid chromatography column. Spectrophotometric detection at 222 nm was used for the identification and determination of the anions. The method was applied successfully to the determination of nitrite and nitrate in human saliva.