基于电感耦合等离子体质谱仪开发的检测器检测模式校正方法  

A detector detection mode correction method developed based on inductively coupled plasma mass spectrometer

作　　者：李凯 王雷[1,2] 王海舟 钊金辉[2] 王小龙 方哲 LI Kai;WANG Lei;WANG Haizhou;ZHAO Jinhui;WANG Xiaolong;FANG Zhe(Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China;NCS Testing Technology Co.,Ltd.,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司,北京100081 [2]钢研纳克检测技术股份有限公司,北京100081

出　　处：《冶金分析》2024年第6期1-10,共10页Metallurgical Analysis

基　　金：科技服务品牌机构发展(2023)。

摘　　要：电感耦合等离子体质谱具有灵敏度高、检出限低等优点,是痕量元素强有力的分析手段之一。然而,许多应用要进行主量元素和痕量元素的同时测量,这就要求仪器具备宽的线性动态范围。基于电感耦合等离子体质谱仪(ICP-MS)用双模式检测器,研究了一种此类检测器检测模式的校正方法,即脉冲-模拟(PA)校正方法。首先根据所要达到的动态范围,确定检测器负高压和正高压,并获取检测器合适阈值电压,确保待测信号被采集到,噪声信号被去除(220 u处计数值小于0.1 cps);然后确定碰撞反应池的He流量,使得待测元素在0.1 ng/L浓度时计数小于10 cps;最后进行信号测试,确定重叠区元素及其测试数据,计算其脉冲-模拟校正系数,简称PA系数,并对其进行三次多项式拟合,得到全质量范围元素的PA系数。选用样条插值与三次多项式进行拟合方式对比,结果表明,在2~250 u全质量数范围内,三次多项式拟合数据更接近原始数据趋势;选用线性动态范围为9个数量级的低、中、高质量数元素Be、Cd、U(0.1 ng/L~100 mg/L)对本校正方法进行了验证,结果表明,校准曲线的决定系数均为1.000,且测得数据对数坐标下校准曲线的决定系数均大于0.9995;选用高温合金标准物质GBW01636中含量跨度有4个数量级的Cu、Ga、As、Bi进行验证,结果显示测定值与认定值基本一致。采用本校正方法可实现线性动态范围达9个数量级的主量元素和痕量元素的同时测定,满足了某些应用中宽浓度范围的测试需求。Inductively coupled plasma mass spectrometry is one of the powerful analytical methods for trace elements due to its high sensitivity and low detection limit.However,the simultaneous determination of major elements and trace elements is performed in many applications,which requires a wide linear dynamic range.Based on the dual-mode detector for inductively coupled plasma mass spectrometer(ICP-MS),a correction method for detection mode of this type of detector,namely Pulse Analog(PA)correction method,was investigated.Firstly,according to the dynamic range desired,the negative high voltage and positive high voltage of the detector was determined.The appropriate threshold voltage for this detector was obtained to ensure that the test signal was collected,and the noise signal was removed(the counting value at 220 u was less than 0.1 cps).Then the flow rate of helium(He)gas for collision reaction cell was determined,so that the counting value of test element at the concentration of 0.1 ng/L was less than 10 cps.Finally,the signal testing was conducted to determine the overlapping elements and their test data.The Pulse-Analog correction coefficient(abbreviated as PA coefficient)was calculated.Cubic polynomial fitting was performed to obtain the PA coefficients of elements in whole mass range.The fitting methods of spline interpolation and cubic polynomial were compared.The results showed that the fitting data by cubic polynomial were closer to the trend of original data within the whole mass range of 2-250 u.The proposed calibration method was validated using low,medium,and high mass number elements of Be,Cd,and U(0.1 ng/L-100 mg/L)with a linear dynamic range of 9 orders of magnitude.The results showed that the determination coefficients of calibration curves were all 1.000,and the determination coefficients of calibration curves were all higher than 0.9995 under logarithmic coordinates of the test data.The superalloy certified reference material of GBW01636,which contained Cu,Ga,As,and Bi with content span in four ord

关 键 词：电感耦合等离子体质谱仪(ICP-MS) 检测模式 脉冲-模拟(PA)校正 线性动态范围 数据拟合 

分 类 号：O657.63[理学—分析化学] TH843[理学—化学] TP311.5[机械工程—仪器科学与技术]