论文部分内容阅读
本文提出以铅空心阴极灯为光源,用石墨炉分子吸收分光光度法测定痕量氯。本法借石墨炉中生成的双原子分子AlCl在261.44nm处的吸收,用铅灯非灵敏线261.418nm测定它的吸收强度,并讨论了最佳的实验条件。在铝溶液中加入硝酸镧和柠檬酸可增强AlCl吸收和降低AlO背景吸收,提出了灵敏度增强和背景降低的机理。也讨论了其他共存离子及酸度对AlCl分子吸收的影响。应用镀碳化物石墨管改善了测量精密度,延长了管子寿命。本方法的灵敏度(1%吸收)为8.5ng/mL,相对标准偏差为2%,检出极限为5.7×10~(-10)g。
In this paper, lead hollow cathode lamp as light source, graphite furnace molecular absorption spectrophotometric determination of trace chlorine. The law by the graphite furnace generated diatomic molecule AlCl absorption at 261.44nm, with lead non-sensitive line 261.418nm determination of its absorption intensity, and discussed the best experimental conditions. The addition of lanthanum nitrate and citric acid to the aluminum solution can enhance the AlCl absorption and reduce the background absorption of AlO, and the mechanism of enhanced sensitivity and background reduction is proposed. The effect of other coexisting ions and acidity on the absorption of AlCl molecules was also discussed. The use of carbide-coated graphite tubes improves measurement precision and extends tube life. The sensitivity (1% absorption) of the method was 8.5 ng / mL with a relative standard deviation of 2% and a detection limit of 5.7 × 10 -10 g.