交流电弧光电直读发射光谱法测定有机土壤中银锡硼  

Determination of sliver,tin and boron in organic soil by alternating current arc optoelectronic direct reading emission spectrometry

作　　者：兰明国 李飞 陈贵仁 何袖辉 郭家泽 石友昌 LAN Mingguo;LI Fei;CHEN Guiren;HE Xiuhui;GUO Jiaze;SHI Youchang(Kunming General Survey of Natural Resources Center,China Geological Survey,Kunming 650100,China;Technology Innovation Center for Analysis and Detection of the Elemental Speciation and Emerging Contaminants,China Geological Survey,Kunming 650100,China)

机构地区：[1]中国地质调查局昆明自然资源综合调查中心,云南昆明650100 [2]中国地质调查局元素形态与新污染物检验检测技术创新中心,云南昆明650100

出　　处：《冶金分析》2024年第9期45-52,共8页Metallurgical Analysis

基　　金：中国地质调查局地质调查项目(DD20243335)。

摘　　要：建立有机土壤中银、硼、锡的分析方法对地表基质调查评价项目具有重要意义。在采用交流电弧光电直读发射光谱法测定碳含量较高的有机土壤样品时,极易引起电弧激发不稳定、样品飞溅等问题,影响测定结果的准确性。本文采取将样品高温灰化预处理除去有机碳后,将缓冲剂与样品混匀后经交流电弧激发,采用交流电弧光电直读发射光谱法对样品进行测定,建立了有机土壤中银、锡、硼的测定方法。对预处理条件进行了优化,结果表明,将样品于600℃高温灰化2 h预处理后测定,可以显著提高测定结果的稳定性,且不会造成样品中银、锡、硼的损失。对激发电流进行了优化,确定激发电流以4 A起弧预激发,起弧3 s后升到二级电流17 A,保持22 s的两级电流激发条件。选用硅酸盐光谱分析标准物质,以分析线对各自扣除背景后的强度比对数值为纵坐标,以基物浓度值的对数值为横坐标,采用一次拟合的方式绘制校准曲线,校准曲线的相关系数均不小于0.9995。方法中银、锡、硼的检出限分别为0.0009、0.21和0.15μg/g。按照实验方法测定土壤标准物质中银、锡、硼,结果的相对标准偏差(RSD,n=12)不大于6.3%,测定值与理论值的对数偏差ΔlgC≤0.049,满足行业标准DZ/T 0258—2014及DD 2005—01中的方法精密度、正确度要求。实验方法用于测定有机土壤样品中银、锡、硼,结果的相对标准偏差(n=12)为3.4%~4.9%。The establishment of analysis method for silver,tin and boron in organic soil has importance significance for surface matrix investigation and evaluation projects.During the determination of organic soil samples containing relatively high content of carbon by alternating current arc optoelectric direct reading emission spectrometry,the problems such as unstable arc excitation and sample spattering are easily caused,influencing the accuracy of determination results.In this study,the sample was pretreated by high temperature ashing to remove organic carbon,then it was mixed with buffer agent followed by excitation with alternating current arc.Thus,a determination method of silver,tin and boron in organic soil was established by alternating current arc optoelectric direct reading emission spectrometry.The pretreatment conditions were optimized.The results showed that the pretreatment of sample by high temperature ashing at 600℃for 2 h could significantly improve the stability of determination results.Moreover,it would not cause the loss of silver,tin and boron in sample.The exciting current was also optimized,and the following two-stage current excitation conditions were adopted:the arcing current for preexcitation was 4 A for 3 s,and then it increased to secondary current of 17 A for 22 s.The certified reference materials of silicate for spectral analysis were selected.The calibration curves were plotted by linear fitting with the strength ratio logarithm of analytical line after deducting the background as ordinate,and the concentration logarithm as abscissa.The correlation coefficients of calibration curves were all no less than 0.9995.The limits of detection for silver,tin and boron were 0.0009,0.21 and 0.15μg/g,respectively.The contents of silver,tin and boron in certified reference materials of soil were determined according to the proposed method,and the relative standard deviations(RSDs,n=12)of determination results were not more than 6.3%with logarithic deviation of determination results from theoretical

关 键 词：交流电弧发射光谱法 有机土壤 银 锡 硼 

分 类 号：O657.31[理学—分析化学] X833[理学—化学]