土壤和马铃薯中元素铬的激光诱导击穿光谱研究

利用激光诱导击穿光谱(LIBS)技术对马铃薯及其生长土壤中的元素铬的光谱特性进行了研究。在425~430nm波长范围内分析比较了土壤样本和马铃薯样本中Cr元素的等离子体特征谱线,选取铬元素425.435nm的特征谱线作为分析线,测定了不同Cr掺杂浓度下的等离子体特征谱线强度,并建立了定标曲线。结果表明:在相同的Cr掺杂浓度下,由于土壤样本基体效应的存在,其特征谱线强度要整体高于马铃薯样本;根据元素谱线强度与浓度的关系,在低浓度条件下,铬元素谱线强度随浓度的增加而增加;通过定标曲线计算得到铬元素在土壤样本和马铃薯样本中的检测限分别为22.6μg·g-1和17.5μg·g-1。

Research on Chromium in Soil and Potato by Laser-induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy （LIBS） technique was used to research the spectral characteristics of chromium in the potato and its growth soil.In 425～430 nm wavelength range,Cr plasma characteristic spectral line was compared and analyzed in soil and potato samples.With the characteristic spectral line of Cr （Cr：425.435 nm） as the analysis line,the plasma characteristic spectral line intensity was determined in different Cr-doping concentrations,and the calibration curve was established.Results showed that under the same concentration of Cr-doping,the characteristic spectral line intensites of the soil samples as a whole were higher than that of potato samples because of its matrix effect; based on the relationship of spectral line intensity and concentration,under the condition of low concentration,chromium spectral line intensity increaseed with the increase in the concentration; calculated by the calibration curve,the LOD （limit of detection） of chromium in soil samples and potato samples were 22.6 μg · g^-1 and 17.5 μg · g^-1.