Qing Yongchao, Hang Yiping, Wanjaul Ruth, Jiang Zucheng, Hu Bin
College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, Hubei, PR China.
Anal Sci. 2003 Oct;19(10):1417-20. doi: 10.2116/analsci.19.1417.
The adsorption behavior of gold (Au), silver (Ag) and palladium (Pd) on nanometer-size titanium dioxide (NSTD) at low concentrations was studied using inductively coupled plasma atomic emission spectrometry (ICP-AES). A preconcentration procedure of the analytes was carried out using NSTD as a solid-phase extractant before their determination by ICP-AES. The optimum conditions for adsorption were studied in detail, and under the condition that Au, Ag and Pd ions could be adsorbed and recovered quantitatively. The static adsorption capacities of Au, Ag and Pd on NSTD were 22.63, 14.06 and 11.82 mg/g, respectively. For the elution of gold, silver and palladium, a mixture of 5% thiourea solution and 3 mol L(-1) HNO3 was used. The parameters tested included: pH conditions, contact time of the analytes with NSTD, flow rate, adsorption capacity and sorption kinetics. According to the definition of IUPAC, the detection limits (3sigma) of this method for Au, Ag and Pd with an enrichment factor of 50 were (0.016), (0.006) and (0.012) microg mL(-1), respectively, the relative standard deviations (RSD) were 8.7%, 4.5% and 7.4%, respectively (n = 6). Some geological samples were determined with satisfactory results.
采用电感耦合等离子体原子发射光谱法（ICP-AES）研究了金（Au）、银（Ag）和钯（Pd）在低浓度下于纳米尺寸二氧化钛（NSTD）上的吸附行为。在通过ICP-AES测定分析物之前，使用NSTD作为固相萃取剂对分析物进行预富集。详细研究了吸附的最佳条件，在此条件下Au、Ag和Pd离子能够被定量吸附和回收。Au、Ag和Pd在NSTD上的静态吸附容量分别为22.63、14.06和11.82 mg/g。对于金、银和钯的洗脱，使用5%硫脲溶液和3 mol L⁻¹ HNO₃的混合物。测试的参数包括：pH条件、分析物与NSTD的接触时间、流速、吸附容量和吸附动力学。根据国际纯粹与应用化学联合会（IUPAC）的定义，该方法对富集因子为50的Au、Ag和Pd的检测限（3σ）分别为（0.016）、（-1）（0.006）和（0.012）μg mL ，相对标准偏差（RSD）分别为8.7%、4.5%和7.4%（n = 6）。对一些地质样品进行了测定，结果令人满意。
