基体干扰对ICP-AES分析土壤样品中主、次量元素的影响研究

为了研究分析方法中的干扰因素对于分析结果的影响程度，针对地球化学中常用的分析手段ICP-AES法，选择土壤标准物质采用与被测样品相同消解方法，作为工作校准曲线来抵消基体影响因素。比较了在土壤基体和无土壤基体条件下测得的土壤样品中各主、次量元素结果的相对偏差，分析了其中联系和规律。发现无土壤基体干扰的结果RE值均在0左右浮动，正负偏移比例基本一致，若排除谱线干扰因素的话，基体匹配方法能有效消除土壤中基体干扰影响。而土壤基体干扰对Al，Ca，Fe，Mg，P，Ti和Ba元素分析结果有较大负偏差影响，最大偏离差Mg 279.5 nm谱线达-14.49%，影响程度排序为Ti，Mg＞P，Fe＞Ca，Ba＞Al，对其他元素Na，Cr，Cu，V，Li，Mn，Ni和Sr则无明显影响。与原本设想的结果相反，基体干扰对我们视作基体的高含量元素测试结果影响十分大，反而对次量元素影响表现并不显著。在综合基体干扰中，Ca和Mg两元素自身组分含量影响权重明显，表现为自身组分含量与分析结果相对偏差值有明显线性相关性。其他元素自身组分与基体影响结果无线性趋势，自身含量的影响权重很小。谱线的选择，干扰因素的排除对结果的确定十分重要。干扰影响的因素和规律一直是ICP光谱学者致力研究探索的课题。这些研究结果对ICP-AES分析土壤样品时谱线的选择及结果准确度的判定有很好的指导意义。

Research on the Matrix Interference on Major and Minor Elements in Soil Samples with ICP-AES

According to the commonly used method of analysis with ICP‐AES in geochemistry ,to study the influence factors of interference from the analysis results ,standard soil substances were selected to be the calibration curve of work ,and the same method of digestion with soil samples was used to balance and eliminate the matrix interference .The concentrations of major and minor elements in soil samples were measured ;the relative deviation of the results was compared under conditions of soil matrix and non‐soil matrix interference ;the relations and laws were being analyzed .The relative deviation (RE% ) of testing results un‐der non‐soil‐matrix interference were found floating around zero ,the ratios of positive deviation and negative deviation were al‐most the same .Excluding the factors of spectral interference ,the method of matrix matching can effectively eliminate the effects of matrix interference on soil .It was found that the analysis results of major elements ,such as Al ,Ca ,Fe ,Mg ,P ,Ti and Ba , were influenced negatively greatly under the condition of soil matrix interference ,The maximum deviation of Mg 279.5 nm was up to -14.49% .The degree of influence ranking showed as Ti ,Mg>P ,Fe>Ca ,Ba>Al .However ,there is no obvious effect on other elements ,including Na ,Cr ,Cu ,V ,Li ,Mn ,Ni and Sr .Contrary to the original ideas ,the matrix interference effected greatly on the results of elements of high content ,nevertheless ,the effects on minor elements were not significant .As to the comprehensive matrix interference ,the large proportion of interference from component self‐content appeared of elements of Ca and Mg ,because obvious linear correlation was found between component self‐content and the relative deviation of the testing re‐sults of Ca and Mg .But no linear trend appeared between the self‐contents of other elements and the results of matrix interfer‐ence ,indicating that the influence weight from self‐content of other elements was very small .It was very important to select the right spectral lines ,and remove the factors of interference to determinate the results of measurement .Factors and rules of inter‐ference effect has always been the research topic by all of scholars in the research field of ICP spectrum .On the guidance of a‐bove research results ,the spectral lines will be selected and the accuracy judged reasonably ,when soil samples being analyzed by IC P‐A ES .