制备了负载5-(2-羟基-5-硝基苯偶氮)-硫代若丹宁(HNATR)的多孔石墨化碳黑并用作分离金的固相萃取柱填充剂。含金样品以1.0 mol/L的磷酸介质过柱,金定量吸附在小柱上,用0.1 mol/L的硫代硫酸钠洗脱小柱上富集的金,可实现样品中低浓度金的高倍数富集和与大部分干扰离子的分离。用火焰原子吸收光谱法测定洗脱液中的金,在选定实验条件下,吸光度与Au(Ⅲ)含量在0.05-3.0μg/mL范围内呈线性关系,线性回归方程的相关系数r=0.999 6;方法用于矿石和环境水样中金的测定,相对标准偏差在2.2%-3.2%之间,加入标准回收率在88%-104%之间。
The porous graphitization carbon black loaded with 5-(2-hydroxy-5-nitrophenylazo)-thiorhodanine(HNATR)was prepared,and used as a filler of solid phase extraction cartridge for separation of Au. Gold could be adsorbed quantitatively when gold-bearing samples flowed through the cartridge in 1.0 mol/L of phosphoric acid medium. The enriched gold in cartridge was eluted with 0.1 mol/L of sodium thiosulfate,realizing the high multiples enrichment of low concentration gold and the separation from most interfering ions. Au in the eluate was measured by flame atomic absorption spectrometry. Under the chosen experimental conditions, the absorbency was linear with the Au concentration in the range of 0.05-3.0 μg/ml with the correlation coefficient(r) of 0. 999 6. This method was used to measure gold in ore and environmental waste samples with RSD in the range of 2.2%- 3.2% and addition standard recovery of 88%-104%.