对氰含量在0.8mg/L升以上的水样,一般采用硝酸银滴定法测定氰化物.其原理是Ag~+与CN~-形成可溶性的银氰络合物[Ag(CN)_2]~-,用指示剂指示过量银离子的存在以显示滴定终点.硝酸银滴定氰化物的常用指示剂有碘化钾(KI)、试银灵(DABR)和百里酚酞(TPC)一试银灵合并指示剂.下面分别予 Cyanide is generally determined by silver nitrate titration for water samples with a cyanide content above 0.8 mg / L, and the principle is that Ag ~ + and CN ~ - form soluble silver cyanide complexes [Ag (CN) _2] ~ -, indicating the presence of excess silver ions with an indicator to indicate the end point of the titration Silver nitrate titration Cyanide commonly used indicators are potassium iodide (KI), test silver (DABR) and thymolphthalein (TPC) The following were given