建立了一种原子捕集火焰原子吸收光谱测量工业废水中痕量铅的方法。原理如下 :捕集管内通冷却水 ,原子蒸汽遇冷凝集在管子外表面 ,捕集一定时间内 ,迅速停止冷却水 ,管温剧烈上升 ,使管子外表面的原子迅速蒸发 ,产生一个强的峰型吸收信号 ,根据信号与浓度呈线形关系进行定量分析。该方法捕集 4min测铅特征质量浓度为 3.72× 10^-3 mg/L ,检出限为 0 .0 11mg/L ,灵敏度比常规法提高了 114倍 ,6次测量的相关系数为 0 .99。

The determination of Pb in wastewater by AAS with the use of trapping is introduced. The principle of it is that the Pb atoms condense on the surface of the stainless steel trapping tube when cooling water is passing through the tube. After a period of trapping the cooling water stops passing. Then the temperature of the trapping tube goes up swiftly , and the atom Pb which has trapped on the surface of stainless steel tube is evaporated, producing a strong absorption peak signal. Quantitative analyses can done according to the linear function of the signal and concent ration. The characteristic concentration is 3. 72×10^-3 mg / L by trapping for 4 min. The detection limit is 0. 011 mg/ L. This method can increase the sensitivity by 114 times as compared to convent ional AAS. The relative std. deviation is 0. 99 in 6 times of Pb determination.