采用激光诱导击穿光谱技术分析安徽怀远农亢农场土壤样品中微量元素Mn的含量分布情况。实验中选取403.1nm作为Mn元素的分析线为,土壤中基体元素Fe作为内标元素,选取的分析线为407.2nm。选取10个土壤样品分别用传统定标方法和内标法建立定标曲线,并对4个待测样品浓度进行预测。实验结果表明,传统定标方法建立的定标曲线的拟合相关系数r为0.954,检测限为93mg·kg-1,待测样品的测量相对误差最大为5.72%;而采用内标法建立的定标曲线的拟合相关系数r为0.983,测量的相对误差减小到4.1%,检测限为71mg·kg-1。说明采用LIBS技术对土壤中微量元素Mn检测的可行性,同时,内标法一定程度上可提高测量的精确性。
The trace element of Manganese element in the agricultural farm(Anhui Huaiyuan Nongkang)soil was quantitatively analyzed by Laser-induced breakdown spectroscopy.The line of 403.1nm was selected as the analysis line of Mn.The matrix element of Fe in soil was chosen as the internal calibration element and the analysis line was 407.2nm.Ten soil samples were used to construct calibration curves with traditional method and internal standard method,and four soil samples were selected as test samples.The experimental results showed that the fitting correlation coefficient(r)is 0.954 when using the traditional method,the maximum relative error of the measurement samples is 5.72%,and the detection limit of Mn in soil is 93mg·kg-1.While using the internal standard method to construct the calibration curve,the fitting correlation coefficient(r)is 0.983,the relative error of measurement samples is reduced to 4.1%,and the detection limit of Mn in soil is 71mg·kg-1.The result indicates that LIBS technique can be used to detect trace element Mn in soil.In a certain extent,the internal standard method can improve the accuracy of measurement.