微波消解—石墨炉原子吸收光谱法测定紫菜中的铅

Microwave Digestion--Determination of Lead in Laver by Graphite Furnace Atomic Absorption Spectrometry

应用石墨炉原子吸收光谱法测定紫菜中铅含量，以HNO3-H2O2为氧化剂，微波消解处理样品，磷酸二氢铵作测铅基体改进剂，考察了基体改进剂浓度、灰化温度、原子化温度对吸光值的影响。在最优条件下，低浓度的铅与吸光值具有良好的线性关系，线性方程为：A=0．0058C＋0．0052，r=0．9994，检出限为1．0μg／L。运用该方法测定10次加标样的RSD为1．512％～2．469％，加标回收率为98．4％～101．1％。该方法简单、快速、重现性好，适合日常批量检测。

In order to detect the concentration of laver, graphite furnace atomic absorption spectrometry was used. Microwave digestion technology was applied to pretreat laver, using the HNO3-H2O2 as oxidizing agent, the two ammonium hydrogen phosphate as matrix modifier. This paper investigated the influence of matrix modifier concentration, ashing temperatureand atomization temperature to the light absorption value. Under the best detecting conditions, there was a good linear relationship between the concentration of lead and the absorption value, and the linear equation was A= 0.0058C ＋ 0.0052, the correlation coefficient was 0.9994, the detection limit was 1.0μg/L. The RSD of spiked samples was 1.512%-2.469%, under 10 consecutive detecting, and the rate of recovery was 98.4%-101.1%. This method was simple, speedy, has a good reproducibility, and it＇s suitable for daily batch testing