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钼酸盐目视滴定铅以及钼酸铵返滴定法测钼酸根均有报导,但由于与指示剂显色的共存离子的干扰,测定的选择性较低。无论是使用Ag_2S-PbS固膜铅电极作指示电极还是用镀PbO_3的铂丝电极做指示电极,钼酸钠电位滴定铅的干扰都很难消除。Frenzel和Dobcnik近年来提出以草酸钠或铬酸钾为滴定剂、玻璃电极指示电极的pH滴定法测铅,但由于许多金属离子参与滴定反应,使测定的选择性不高。
Molybdate visual titration of lead and ammonium molybdate back titration of molybdate has been reported, but due to interference with the indicator coexisting ions, the selectivity of the assay is low. Both the use of Ag_2S-PbS solid lead electrodes as lead electrodes or lead-free electrodes coated with PbO_3 as indicator electrodes, lead molybdate titration is difficult to eliminate the interference. In recent years, Frenzel and Dobcnik proposed to use sodium oxalate or potassium chromate as titrant, and the glass electrode indicates the pH value of the electrode to measure the lead. However, due to the participation of many metal ions in the titration reaction, the selectivity of the determination is not high.