Reaction between Long-Chain Cation-active Salts and Sodium Hexametaphosphate

DURING an investigation involving the use of cation-active salts such as cetyl pyridinium bromide in conjunction with sodium hexametaphosphate, it was observed that precipitates frequently occurred. Further observations on distilled water solutions showed that cation-active long-chain salts of this class give rise to intense turbidity and in some instances to complete precipitation when treated with sodium hexametaphosphate (“Calgon”).