微萃取火焰原子吸收法测定水中微量铅

Determination of trace lead in the water by atomic absorption spectrometry combined with microextraction

建立了分散液-液微萃取与火焰原子吸收光谱结合测定水中微量铅的实验方法.该方法为火焰原子吸收光谱法提供了一种易雾化的、非易燃的有机萃取体系.选定并优化了萃取的影响参数后,计算出经过富集与未经过富集的标准曲线的斜率比为330.标准曲线在2～70μg/L的质量浓度范围内呈线性,检测限为1.4μg/L.重复7次测量50μg/L的铅溶液的相对标准偏差为0.2﹪.对自来水、井水、湖水等样品进行了分析,回收率为104.4﹪～109.6﹪.

The flame atomic absorption spectrometry （FAAS） was combined with the dispersive liquid-liquid microextraction （ DLLME ） for determination of trace lead in the water samples. The new system was employed for the microvolume nebulization of the non-flammable chlorinated organic extracts. Some effective parameters on the microextraction and the complex formation were selected and optimized, under the optimized conditions, the slope of the calibration curve after enrichment is 330 times as one before. The calibration curve is linear in range of 2.0-70 μg/L with a detection limit of 1.4 μg/L. The relative standard deviation（ R.S.D. ） for seven replicate measurements of 50 μg/L of lead is 0.2%. The percent recoveries of lead in tap, well and lake samples ranges from 104.4% to 109.6%.