辉光放电光谱法测定因瓦合金中14种元素

Determination of fourteen elements in invar alloy by glow discharge optical emission spectrometry

采用11种与因瓦合金成分含量相接近的镍基合金标准样品绘制校准曲线,建立了基本不需要样品处理即可对因瓦合金中14种元素(C、Si、Mn、P、S、Ni、Cr、Mo、Cu、Al、Nb、Ti、Co、Fe)同时测定的辉光放电光谱法。确定辉光光谱仪检测因瓦合金的最佳条件:模块电压和相电压分别为8.22V和3.82V;功率为70 W;冲洗时间为80s;积分时间为60s。以各元素质量分数为横坐标,其对应的光谱强度为纵坐标绘制校准曲线,各元素校准曲线的相关系数均在0.99以上。采用实验方法对因瓦合金实际样品进行分析,结果显示:Cr、Ni、Mo、Ti、Fe的质量分数均大于0.3%,各元素测定值的相对标准偏差(RSD,n=11)均不大于1%;C、Si、Mn、P、S、Cu、Al、Nb、Co的质量分数均小于0.3%,各元素测定值的RSD(n=11)均小于5%。将实验方法应用于对因瓦合金样品中14种元素的测定,测得结果与滴定法测定Ni和Fe、高频燃烧红外吸收法测定C和S、电感耦合等离子体原子发射光谱法测定Si、Mn、P、Cr、Mo、Cu、Al、Nb、Ti和Co元素的结果基本一致。

After the calibration curve was prepared using 11 certified reference materials of nickel-based alloy with similar content to invar alloy,a method for simultaneous determination of fourteen elements（C,Si,Mn,P,S,Ni,Cr,Mo,Cu,Al,Nb,Ti,Co and Fe）in invar alloy was established by glow discharge optical emission spectrometry without sample treatment.The optimal conditions of glow discharge spectrometer for the determination of invar alloy were obtained as follows：the module voltage and phase voltage was 8.22 Vand 3.82 V,respectively;the power was 70 W;the flushing time was 80s;the integral time was 60 s.The calibration curves were plotted with mass fraction of each element as horizontal ordinate and its corresponding spectral intensity as vertical coordinate.The correlation coefficients of calibration curves were all higher than 0.99.The actual sample of invar alloy was analyzed by the experimental method.The results showed that the mass fraction of Cr,Ni,Mo,Ti,and Fe were all higher than 0.3%with relative standard deviations（RSD,n=11）all not higher than 1%,the mass fraction of C,Si,Mn,P,S,Cu,Al,Nb and Co were all less than 0.3% with relative standard deviations（RSD,n=11）all less than 5%.The proposed method was applied to the determination of fourteen elements in invar alloy samples.The results were basically consistent with those obtained by titration method（Ni and Fe）,high frequency combustion-infrared absorption method（C and S）or inductively coupled plasma atomic emission spectrometry（Si,Mn,P,Cr,Mo,Cu,Al,Nb,Ti and Co）.