Taylor Drop Test, Chloride, Argentometric (for hi pH waters), 1 drop = 10, 25, 50, 100, or 500 ppm
 
Chloride is one of the major inorganic anions in water and wastewater. High concentrations of chloride may contribute to the corrosion of metal pipes and related structures. A key determination for industrial water treaters, chloride is mainly tested to control blowdown in boilers and bleed-off in cooling systems. Chloride tests are also employed to characterize boiler feedwater and to detect leaks in some types of condensers.
 
Chlorides are determined titrimetrically using either the argentometric or mercuric nitrate method. In the argentometric method, potassium chromate indicates the endpoint by forming red silver chromate with excess silver ions. In the mercuric nitrate method, diphenylcarbazone indicates the endpoint by formation of a purple complex with excess mercuric ions.
 
Note: Bromide and iodide titrate as equivalent chloride concentrations. Sulfite interferes but can be removed with hydrogen peroxide. High orthophosphate and iron may interfere.
 

Analyte	System	Method/Chemistry	Standard/Equivalence or Description	Comparator	Cell
Chloride	Drop test	Argentometric (high pH waters)	1 drop = 10, 25, 50, 100, or 500 ppm Clˉ	NA	9198O