In the system of sulfuric acid phenylglycollic acid cinchonine potassium chlorate, micro amount of tungsten in ammonium molybdate products has been determined by catalytic polarography.

在酸 -苯羟乙酸 -辛可宁 -氯酸钾体 ,催化极谱法测定钼酸铵产微量钨。