流动注射在线液-液萃取-ICP-AES测定土壤和化探样品中痕量铌和钽

应用流动注射在线萃取技术将Nb,Ta萃入甲基异丁酮(MIBK)和磷酸三丁脂(TBP)混合溶剂直接进行ICP-AES测定.研究了流动注射在线萃取-电感耦合等离子体原子发射光谱法测定土壤和化探样品中Nb和Ta的实验条件、流路参数、酸度条件的选择,考察了共存元素的干扰.采样速率为20样@h-1,RSD(n=10)为Nb4.5%;Ta5.1%,测定检出限(K=3)为Nb0.5ng@mL-1;Ta0.8ng@mL-1.方法操作简便、快速,经对国家一级标准物质分析,结果与推荐值一致.

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.