Elimination of Interference in Simultaneous Determination of Trace Ga, In, Ta, W and Mo in Copper, Lead and Zinc Ores by Inductively Coupled Plasma-Mass Spectrometry

A method for correctioin and elimination of interference from matrix and major elements in simultaneously determination of Ga, In, Ta, W and Mo in copper, lead and zinc ores by inductively coupled plasma-mass spectrometry was developed. Interferences from matrix and major elements on the determination were systemically studied. The results showed that 1) when the concentration of Cu or Pb in the sample solution was <200 μg/mL, no interference from Zn on the determinatioin of the elements above was observed. 2) Cu with concentration of >50 μg/mL in the solution caused the negative interference on the determination of Ga, In, Ta, W and Mo. 3) Pb with concentration of >100 μg/mL produced the positive and negative interference on W and Mo, respectively, and the interference couled be eliminated by Sc-Re-La mixed internal standardization or matrix matching method. 4) Pb with concentration of >20 μg/mL caused the positive interference on the determination of Tl and the interference could be effectively relieved or eliminated by selecting ²⁰³Tl as measurement isotope and using matrix matching method or correction coefficient method.