[On-line determination of niobium and tantalum in soil and geochemical exploration samples by inductively coupled plasma atomic emission spectrometry with solvent extraction flow injection].

A new method for the determination of trace niobium and tantalum in soil and geochemical exploration samples by inductively coupled plasma atomic emission spectrometry with solvent extraction flow injection was proposed. The niobium and tantalum were extracted with the mixed solvent of MIBK and TBP at 1 mol.L-1 HF and 4 mol.L-1 H2SO4. Experiment conditions and manifold parameters were investigated in detail. The detection limits were 0.5 x 10(-12) g.L-1 and 0.8 x 10(-12) g.L-1. The proposed method was rapid, simple and accurate, it has been applied to the determination of trace niobium and tantalum in national standard samples. The results were in good agreement with certified values with precisions of 4.5% and 5.1% RSD (n = 10). The sample throughput for niobium and tantalum is 20.h-1.