【摘要】 联合应用几种改善火焰原子吸收分析性能的技术可显著地改善火焰原子吸收的灵敏度和检出限,我们称这种方法为微量火焰原子吸收技术。提出了微量火焰原子吸收技术的理论模式。以矿石及其加工产品中微量金的测定和水中铅与砷的测定为例,详细地讨论了微量火焰原子吸收技术的应用效果。联合应用高效雾化器、高性能空心阴极灯、石英缝管和流动注射在线富集的系统,使测定微量金的信噪比改善950倍,检测限达到0.2ng/ml(3σ),可以测定矿石及其加工产品中0.005g/t以上的金。联合应用高效雾化器、高性能空心阴极灯和石英缝管的系统,使测定铅的信噪比改善67倍,检测限达1.6ng/mL(3σ),可以直接测定水体中ng/ml级的铅。采用联合应用高性能空心阴极灯、石英缝管和HG-3简易氢化物发生器的系统,使测定砷的信噪比改善了430倍,检出限达3.0ng/ml(3α),可以直接测定水体中ng/ml级的砷。更多还原

【Abstract】 The combined use of several kinds of technique for improving analytical performance of flame AAS can markedly modify the analytical sensitivity and detection limits. The technique is referred to as microamount flame atomic absorption technique(MFAAT). A new theoretical model for MFAAT has been proposed in this paper. With the determination of trace Au in ore and the determination of Pb and As in water as examples, the application effectiveness of MFAAT was discussed in detail. The combined use of high efficiency nebulizer (HEN), high performance hollow cathode lamp(HPHCL), slotted quartz tube(SQT) and flow injection analysis (FIA) for the direct determination of trace Au by using flame AAS results in 950 fold improvement of signal to noise ratio, and detection limits down to levels of 0.2ng/mL(3σ), this method can be used for the direct determination of Au down to levels of 0.005g/t in ore. The combined use of HEN, HPHCL and SQT for the determination of trace Pb by using flame AAS results in 67 fold improvement of signal to noise radio and detection limits down to levels of 1.6ng/mL (3σ), it can be used for the direct determination of Pb down to levels of ng/mL in waters. The combined use of HPHCL, SQT and HG-3 hydride generator for the determination of trace As by using flame AAS results in 430 fold improvement of signal to noise ratio and detection limits down to levels of 3.0ng/mL(3σ), it can be used for the direct determination of As down to levels of ng/mL in water.更多还原