由于轻油蒸汽转化制氢催化剂中含有镍、铁、铝等元素,若用 EDTA 络合滴定催化剂中的氧化钙和氧化镁时,这些元素将有很大的干扰。虽然在络合滴定前可用氰化钾和三乙醇胺掩蔽干扰元素,但由于氰化物的毒性,给操作带来了不便。用 B—氨基乙硫醇和 L—半脱氨酸作掩蔽剂,又只能掩蔽少量的重金属离子。使用酒石酸钾钠—三乙醇胺—铜试剂掩蔽,也存在铜试剂络合物影响指示剂终点色变的问题。目前广为采用的六次甲基四胺—铜试剂及乙酸钠—铜试剂或用树脂分离干扰元素后,再用 EDTA 滴定氧化钙和氧化镁 Because light oil steam reforming hydrogen catalyst contains nickel, iron, aluminum and other elements, if EDTA complexation titration of calcium oxide and magnesium oxide catalyst, these elements will have a great disturbance. Although the interference element can be masked with potassium cyanide and triethanolamine prior to the complexometric titration, the operation is inconvenient due to the toxicity of the cyanide. With B-aminoethanethiol and L-half-amino acid as a masking agent, they can only mask a small amount of heavy metal ions. Using potassium sodium tartrate-triethanolamine-copper reagent masking, there is also the problem that copper reagent complexes affect the terminal color change of the indicator. Currently widely used hexamethylenetetramine - copper reagent and sodium acetate - copper reagent or resin separation of interference elements, and then titration with calcium oxide and magnesium oxide