石墨炉原子吸收法测定石脑油中痕量铜铅砷

Determination of trace copper,lead and arsenic in naphtha by graphite furnace atomic absorption spectrometry

以石脑油为原材料,碘-二甲苯为氧化剂,稀硝酸为萃取剂,混合硝酸钯-硝酸镁溶液为基体改进剂,采用石墨炉原子吸收法测定石脑油中痕量铜、铅、砷。结果表明：以硝酸钯-硝酸镁混合溶液[ρ（硝酸钯）和ρ（硝酸镁）均为0.05 g/L]为基体改性剂,对样品进行处理后,测试结果受干扰较小;以碘-二甲苯[w（碘）为1.0%]为氧化剂,硝酸溶液[w（硝酸）为10%]为萃取剂,对样品进行处理后,测定效果最佳,铜、铅、砷的吸光度最大分别为0.231 5,0.168 5,0.206 8;采用石墨炉原子吸收法测定样品中铜、铅、砷的标准偏差为0.4%~0.6%,相对标准偏差为3.7%~5.1%,加标回收率为93%~108%。

With naphtha as raw material, iodine - xylene as oxidizing agent, dilute nitric acid as extraction agent, mixed palladium nitrate -magnesium nitrate solution as matrix modifier, the trace copper, lead and arsenic in naphtha was determined by graphite furnace atomic absorption spectrometry. The results showed that the samples were treated by mixed palladium nitrate -magnesium nitrate solution [ p （ palladium nitrate ） and p （ magnesium nitrate ） were both O. 05 g/L] as matrix modifiers, which had less interference to test results; the samples were treated by iodine - xylene [ w（iodine） 1.0% ] as ox-idizing agent,nitric acid solution [ w （ nitric acid solution） 10% ] as extraction agent,which had the optimum results and the maximum absorbance of copper,lead and arsenic was 0. 231 5,0. 168 5,0. 206 8 respectively. By graphite furnace atomic absorption spectrometry, the standard deviation of copper, lead and arsenic in samples was 0.4% -0.6% ,the relative standard deviation was 3.7% - 5.1% , the recovery were all 93% - 108%.