Determination of gold,palladium and rhodium in geological samples by inductively coupled plasma atomic emission spectrometry after separation and enrichment with modified nano-titanium dioxide
改性纳米二氧化钛分离富集电感耦合等离子体原子发射光谱法测定地质样品中金钯铑

The nano-TiO2 was modified with diphenylsulfourea.The modified nano-TiO2 exhibited strong adsorption capacity to Au3+,Pd2+ and Rh3+,so it was applied to the separation and enrichment of Au3+,Pd2+ and Rh3+.This separation and enrichment method was combined with inductively coupled plasma atomic emission spectrometry(ICP-AES) to establish a new determination method for Au,Pd and Ph in geological samples.The effect of solution acidity,elution conditions and interference ions on the separation and enrichment of analyte was investigated.The result showed that Au3+,Pd2+ and Rh3+ could be quantitatively enriched by modified nano-TiO2 at pH 4.0,while K+,Na+,Ca2+,Mg2+,Zn2+,Ni2+,Ba2+,Co2+,Cd2+ and Mn2+ were not adsorbed.Although Fe2+,In3+ and Ga3+ were partially adsorbed,they had no influence on the determination.The adsorbed precious metal ions could be fully eluted with 20 g/L CS(NH2)2 and 2 mol/L HCl.Under the optimized experimental conditions,the adsorption capacity of adsorbent to Au3+,Pd2+ and Rh3+ was 21.63 mg/g,12.82 mg/g and 19.56 mg/g,respectively.The detection limit(3σ) for Au3+,Pd2+ and Rh3+ was 0.61 ng/mL,0.58 ng/mL and 1.89 ng/mL,respectively.The relative standard deviation(RSD,n=11) was 1.7 %,2.6 % and 1.8 %,respectively.The proposed method was applied to the determination of Au3+,Pd2+ and Rh3+ in reference material(GBW07293).The found results were consistent with the certified values.