摘要
建立了交流电弧-光电直读发射光谱法测定岩石矿物样品中的高含量锡。将样品和固体缓冲剂(由质量比为22∶20∶44∶14的焦硫酸钾、氟化钠、三氧化二铝、碳粉混合而成,内含质量分数为0.007%内标物二氧化锗)振动混匀后直接固体进样。先采用一级电流3A预激发样品,再升到二级电流15A激发样品,截取曝光时间25s;选择次灵敏线(Sn 242.1700nm)作为锡元素分析线,并与锗元素分析线(Ge 270.9626nm)组成分析线对,用电荷耦合器件(CCD)检测器测定,采用离线差减法(即锡和锗信号强度分别减去各自背景强度)去除背景干扰。以地球化学标准物质及其与基物(由质量比为72∶15∶4∶4∶2.5∶2.5的二氧化硅、三氧化二铝、三氧化二铁、纯白云石、硫酸钠、硫酸钾混合而成)混合而成的标准物质-基物样品制作校准曲线。结果显示:方法适用的测定范围为370~12700μg·g^(-1),检出限(3s)为62.41μg·g^(-1);分析3种标准物质12次,得到的测定值的相对标准偏差(RSD)均不大于2.0%;分析了3种标准物质-基物样品,测定值与已知值的对数差值(Δlgw)的绝对值均小于0.05。
A method on determination of high content of tin in rock and mineral samples by alternating current arc-optoelectronic direct reading emission spectrometry was established.The sample and solid buffer[composed of potassium pyrosulfate,sodium fluoride,aluminum oxide,and carbon powder with mass ratio of 22∶20∶44∶14(containing 0.007%internal standard germanium dioxide)]were mixed by vibration.After direct injection in solid form,the sample was pre-excited by primary current of 3 Aand excited by secondary current of15 A,with the exposure time of 25 s.The sub-sensitive line(Sn 242.1700 nm)was selected as analytical line for tin,to form an analytical line pair with the germanium element analytical line(Ge 270.9626 nm).The CCD detector was used for determination.The background interference was removed by off-line subtraction which tin and germanium signal intensities were subtracted from their respective background intensities.The calibration curve was made with the geochemical reference materials and the mixed samples consisted of reference material and basematerial(composed of silicon dioxide,aluminum oxide,iron oxide,pure dolomite,sodium sulfate,and potassium sulfate with the mass ratio of 72∶15∶4∶4∶2.5∶2.5).The results showed that the detection range available for this method ranged from 370 to 12700μg·g^(-1),with detection limit(3 s)of 62.41μg·g^(-1);RSDs of the measured values were not more than 2.0%after twelve times of analysis of three reference materials;the 3 mixed samples consisted of reference materials and base-materials were analyzed,the absolute values of the logarithm difference between the determined values and the known values were all less than 0.05.
作者
肖细炼
朱园园
陈燕波
杨小丽
XIAO Xilian;ZHU Yuanyuan;CHEN Yanbo;YANG Xiaoli(Wuhan Center of China Geological Survey,CGS,Wuhan 430205,China;Central South China Innovation Center for Geosciences Wuhan 430205,China)
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2021年第3期241-246,共6页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
中国地质调查局地质调查项目(121201009000150002)。
关键词
交流电弧
光电直读发射光谱法
高含量锡
岩石矿物
alternating current arc
optoelectronic direct reading emission spectrometry
high content of tin
rock and mineral
