Wu Hong, Jin Yan, Luo Mingbiao, Bi Shuping
School of Chemistry and Chemical Engineering, Key Laboratory of MOE for Life Science & State Key Laboratory of Coordination Chemistry, Analytical Center, Nanjing University, Nanjing, China.
Anal Sci. 2007 Sep;23(9):1109-12. doi: 10.2116/analsci.23.1109.
A simple and sensitive flow-injection on-line separation and preconcentration system coupled to hydride generation atomic fluorescence spectrometry (HG-AFS) was developed for ultra-trace lead determination in water, wine, and rice samples, with the salient advantages of its minimization of transition-metal interferences and tolerance to an ethanol matrix. A lead hydroxide precipitate was achieved by the on-line merging of a sample and an ammonium buffer solution and collected onto the inner walls of a knotted reactor (KR). Removal of the residual solution from KR was achieved by air flow, and dissolution of the precipitate was carried out by using 0.2 mol l(-1) HCl. With a sample consumption of 11.7 ml, an enhancement factor of 16 was obtained at a sample throughput of 30 h(-1). The limit of detection (3s) was 16 ng l(-1) and the precision (RSD) for 1.0 microg l(-1) Pb was 3.4%.
建立了一种简单灵敏的流动注射在线分离富集系统，与氢化物发生原子荧光光谱法（HG-AFS）联用，用于测定水、葡萄酒和大米样品中的超痕量铅。该系统具有显著优点，即能最大程度减少过渡金属干扰并耐受乙醇基质。通过在线合并样品和铵缓冲溶液形成氢氧化铅沉淀，并收集在打结反应器（KR）的内壁上。通过气流从KR中去除残留溶液，并使用0.2 mol l(-1) HCl溶解沉淀。进样量为11.7 ml时，在30 h(-1)的进样通量下富集倍数为16。检测限（3s）为16 ng l(-1)，1.0 μg l(-1) Pb的精密度（RSD）为3.4%。
