多元谱线拟合技术在电感耦合等离子体原子发射光谱法测定镍基高温合金GH4720Li中硼的应用

Application of multi-component fitting technique for determination of boron in nickel-based superalloy GH4720Li by inductively coupled plasma atomic emission spectrometry

用盐酸和过氧化氢(或硝酸)溶解样品,采用多元谱线拟合技术(MSF)校正光谱干扰,消除了合金中镍、铬、钴、铝、钛、钨、钼、铁和锰等共存元素对测定的影响,实现了采用电感耦合等离子体原子发射光谱法(ICP-AES)测定镍-铬-钴系样品中硼的测定。分别采用B249.677nm、B 208.957nm和B 182.578nm为分析谱线,在合成标样和镍-铬-钴系标样两种校准模式下绘制两种校准曲线,结果表明,无论采用何种校准模式,若不选用MSF模型进行校正,则在各分析谱线处所得校准曲线的相关系数均较差,其最大值仅为0.828(谱线B208.957nm),而采用MSF模型校正后,在谱线B 249.677nm和B 208.957nm处的相关系数均大于0.990,B 208.957nm处的相关系数大于0.920。采用MSF模型进行校正,分别以合成标样和镍-铬-钴系标样两种校准模式对3个不同含量水平的镍-铬-钴系标样进行测定,结果表明,采用合成标样校准模式所得结果要优于镍-铬-钴系标样校准模式。因此,将MSF模型校正和合成标样校准模式作为测定镍-铬-钴系样品中硼的分析条件。考虑到若采用谱线B182.578nm为分析谱线,会增加分析时间和增大成本,同时在谱线B 208.957nm处的相关系数、与认定值的吻合性均低于谱线249.677nm,实验最终选用B 249.677nm作为分析谱线。精密度试验结果表明,样品A40和198在谱线B 249.677nm处测定结果的相对标准偏差(RSD,n=8)为2.0%~11.0%,方法检出限为0.000 5%。在选定的实验条件下,对GH4720Li合金样品进行分析,并采用离子选择电极法进行方法对照试验,结果表明两种方法测定结果基本一致。

The sample was dissolved with hydrochloric acid and hydrogen peroxide(or nitric acid).The multi-component spectral fitting(MSF)technique was used to correct the spectral interference and eliminate the influence of coexisting elements including nickel,chromium,cobalt,aluminum,titanium,tungsten,molybdenum,iron and manganese on the determination.The determination method of boron in nickel-chromium-cobalt alloy sample by inductively coupled plasma atomic emission spectrometry(ICP-AES)was established.B 249.677 nm,B 208.957 nm and B 182.578 nm were selected as the analytical lines.Two calibration curves were prepared using two standard modes,i.e.,synthetic sample and standard sample of nickelchromium-cobalt alloy.The results showed that whether which calibration mode was adopted,the correlation coefficients of calibration curves were poor if the correction was not conducted by MSF model.The maximum value was only 0.828(for line of B 208.957 nm).After correction using MSF model,however,the correlation coefficients at lines B 249.677 nm and B 208.957 nm were both higher than 0.990.Meanwhile,the correlation coefficient at line B 208.957 nm was 0.920.Three standard nickel-chromium-cobalt alloy samples with different boron content were determined by two calibration modes with correction using MSF model,respectively.The results indicated that the determination results of calibration mode using synthetic sample were better than those of calibration mode using standard sample.Therefore,the MSF model and the calibration mode using synthetic sample were used as the analysis conditions for boron in nickel-chromium-cobalt alloy samples.If B 182.578 nm was selected as analytical line,the analysis time and cost would be increased.Moreover,the correlation coefficient and consistence to certified values at line B 208.957 nm were lower than those at line B 249.677 nm.Thus B 249.677 nm was finally selected as the analytical line in this study.The precision tests showed that the relative standard deviation(RSD,n=8)of determined results at line B 249.677 nm were between 2.0%and 11.0%for samples A40 and 198.The detection limit of method was 0.000 5%.Under the selected experimental conditions,the alloy sample GH4720 Li was analyzed and compared with ion selective electrode method.The results indicated that the determination results of two methods were basically consistent.