微量火焰原子吸收法测定水中铅

Determination of Pb in Water by Micro-amountFlame Atomic Absorption Technique

本文研究了高性能空心阴极灯－高效零化－单缝石英管系统这一微量火焰原子吸收技术在微量Ｐｂ测定方面的应用。在Ｐｂ的最灵敏线２１７．０ｎｍ处和次灵敏线２８３．３ｎｍ处考察了微量火焰原子吸收技术对嗓音、灵敏度及检出限的改善程度。分别得到噪音改善２．０８倍、３．８６倍；提高灵敏度３２倍、９．９倍；信噪比改善倍数６７和３８的满意结果。选择Ｐ６的最灵敏线２１７．０ｎｍ测定自来水及合成样品中的Ｐｂ，特征浓度可达６ｎｇ／ｍＬ／１％，检测限达１．９ｎｇ／ｍＬ（３σ），测定精度ＲＳＤ２．３％（２０．６ｎｇ／ｍＬ）。

A new micro-amount flame atomic absorptiontechnique was devefoped. The system of highperformance hollow cathode lamp-highly effectivenebulizer -single-slotted silica tube ,was studied for the determination of trace Pb.The ratio of signal to noise,sensitivity and detection limit have been improved bymicro-amount flame atomic absorption technique withthe most sensitive analvtical lines Pb 217.0nm and Pb283.3nm,The improvements in noise are 2.08,3.86fold ;improvements in sensitivity are 32.99 fold;improvements in signal to noise ratio(s/n)are 67, 38fold recpectivly,The analytical line 217.0nm waschosen for the determination of Pb in tap water andsynthetic samples,The sensitivity of Pb is 0.006μg/mL/1%. The detection limit of Pb is 0.0019μg/mL,RSD is 2.3%for 20.6ng/mL Pb.The precisions forthe detenmination of Pb in of tap water and svntheticsample containing 10.4ng/mL,235, 2ng/mL Pb are5.6%,0.6%,and the recoveries are 95～115%,92～100%respectively.