A new titrant for perchlorate: Cetyltrimethylammonium bromide.

Cetyltrimethylammonium bromide is used in the precipitation titration of perchlorate, with potentiometric end-point detection. A perchlorate, fluoroborate or nitrate ion-selective electrode may be used. The method is more sensitive than the commonly used titration with tetraphenylarsonium chloride. It can be used over the pH range from 1.20 to at least 12.8. The titrant is much cheaper than tetraphenylarsonium chloride.