双指示电极电位滴定-流动注射分析法测定铀矿石中铀

将双指示电极电位滴定与流动注射分析方法相结合，建立了准确测定铀矿石中铀的新方法。在该方法中，用钒酸铵和氟化钠的混合溶液作为滴定剂，在流通池中同时插入铂电极和氟离子指示电极，在滴定过程中的任一滴定点，流出液的铀电位E_U和滴定进度f可由两个电极的电位测定值同时获得。该方法消除了体积读数产生的误差，又减少了试剂和样品的消耗量，且可自动批量进样，大大提高了检测速度，分析过程中，辐射强度小。应用该方法对铀矿中的铀进行了测定，其相对标准偏差小于0.5%(n=3)，回收率为99.3%~100.3%。

Determination of Uranium in Uranium Mine by Means of Flow Injection Analysis With Potentiometric Titration Using Double Indicator Electrodes

A new flow injection analysis method coupled with potentiometric titration using double indicator electrodes for the precise determination of uranium in uranium mine has been developed. In this method, the titrant is a mixture of ammonium vanadate and sodium fluoride, both platinum electrode and fluoride electrode are inserted in the flow cell. In a process of titration, both the potential of uranium and the volume ratio of the titrant and the titration solution can be obtained simultaneously from the two electrodes at each titration point. The method is free of volumetric and reduces the consumption of reagent and sample. The method is also very quick in analysis rapidity and depresses radiant intensity in the process of analysis. The method has been applied to the determination of the uranium concentrate in uranium mine with the relative standard deviation less than 0.5% (n=3) and the recovery of 99.3%-100.3%.