石墨炉原子吸收法连续测定土壤中铅、镉、砷的含量

用混和酸硝化处理同一样品,采用基体改进技术连续测定土壤中重金属铅、镉、砷的含量。通过灰化温度和特征波长的优化选择,避免了待测元素的损失。同时采用基体改进技术,避免了土壤中复杂基体的影响。本方法中铅、镉、砷的检出限分别为0.16mg/kg,0.012mg/kg,0.93mg/kg。通过重复性试验和加标回收试验,验证了方法的可靠性,回收率可达98%±5%,可实现同一样品的连续、快速测定,且最大限度地减少了土壤内复杂基体对测定的干扰。

Determination of Lead, Cadmium, Arsenic in Soil by Graphite Furnace AAs

Sample of soil is leached with mixed acids, the amount of lead ,cadmium, arsenic is determinted simultaneously by adding matrix modifier and electing pretreatment temperature and characteristic wavelength, and the effect of coexisting elements is avoided. The detection limits of Pb,Cd,As are 0.0.16mg·kg~(-1),0.01mg·kg~(-1),0.25 mg·kg~(-1) respectivily. Through repeated tests and adding standard sample ,the realibility of the method is testified,and the recoveries obtained are in the range of 93.0%～103.0%.The elements could be determined rapidily and continiously for a sample.