Determination of trace iron in high purity graphite by high resolution continuum source graphite furnace atomic absorption spectrometry with high temperature ashing
CHEN Junqi
Henan University of Technology,Zhengzhou 450001, China
Abstract：High temperature ashing-acid dissolution method is a common sample pretreatment method for determination of impurity elements in high purity graphite because of its simple operation and low reagent dosage. However, the ashing residue will be adhered onto vessels after high temperature ashing, which is hardly fully decomposed with acid. Meanwhile, the oxidation reaction between carbon in high purity graphite and platinum dish will occur at high temperature, thus reducing its service life. The ash-free filter paper was pre-lined between the platinum dish and sample. After high temperature ashing, the ashing residue was pre-quenched with nitric acid. During this process, the solution was stirred for several times with teflon rod along the bottom of platinum dish. Then hydrofluoric acid and perchloric acid were added successively to dissolve the ashing residue by heating. The solution was determined by high resolution continuum source graphite furnace atomic absorption spectrometry(HR-GF-AAS). Thus, a method for determination of trace iron in high purity graphite was established. The results showed that the pre-introduction of ash-free filter paper on the bottom of platinum dish could effectively prevent the sample residue from adhering on the bottom of platinum dish after high temperature ashing as well as the reaction between carbon and platinum dish. The dissolution tests of ashing residue indicated that the solution easily splashed during the evaporation to small volume when the mixed acid system did not contain perchloric acid. The use of perchloric acid for evaporating smoke could reduce the digestion temperature and effectively prevent solution from splashing. Therefore, the ashing residue was decomposed with nitric acid-hydrofluoric acid-perchloric acid. Under the selected experimental conditions, the quadratic equation least square method was fitted with iron mass concentration in the range of 1-50 ng/mL. The determination coefficient (R2) was 0.999 8. The limit of detection was 0.001 6 μg/g, and the limit of quantification was 0.005 3 μg/g. The proposed method was applied for determination of iron in high purity graphite samples. The relative standard deviations (RSD, n=6) were between 0.82% and 3.6%, and the recoveries were between 96% and 104%. The determination results were in good agreement with those obtained by collision reaction cell-inductively coupled plasma mass spectrometry.
陈俊旗. 高温灰化-高分辨率连续光源石墨炉原子吸收光谱法测定高纯石墨中痕量铁[J]. 冶金分析, 2022, 42(9): 55-60.
CHEN Junqi. Determination of trace iron in high purity graphite by high resolution continuum source graphite furnace atomic absorption spectrometry with high temperature ashing. , 2022, 42(9): 55-60.
[1] Yukihiro Koshino,Akira Narukawa.Determination of trace metal impurities in graphite powders by acid pressure decomposition and inductively coupled plasma atomic emission spectrometry[J].Analyst,1993,118:827-830. [2] Mitsuyoshi Watanabe,Akira Narukawa.Determination of impurity elements in high purity graphite by inductively coupled plasma atomic emission spectrometry after microwave decomposition[J].Analyst,2000,125:1189-1191. [3] 中华人民共和国国家发展和改革委员会.YB/T 5159—2007 高纯石墨制品 硅和铁的光谱测定:粉末法[S].北京:冶金工业出版社,2007. [4] 中华人民共和国工业和信息化部.YB/T 5157—2016 高纯石墨制品中铁的测定:邻二氮菲分光光度法[S].北京:冶金工业出版社,2016. [5] 杨倩倩,何石,胡月,等.电感耦合等离子体原子发射光谱法测定高纯石墨中9种元素[J].冶金分析,2016,36(3):49-53. YANG Qiaqian,HE Shi,HU Yue,et al.Determination of nine elements in high purity graphite by inductively coupled plasma atomic emission spectrometry[J].Metallurgical Analysis,2016,36(3):49-53. [6] 中华人民共和国工业和信息化部. YB/T 4590—2017 硅材料用高纯石墨制品中杂质含量的测定 电感耦合等离子体发射光谱法[S].北京:冶金工业出版社,2017. [7] 张爱滨,魏进武,王燕,等.顺序扫描ICP-AES法测定高纯石墨灰分中14种杂质金属元素的方法研究[J].青岛海洋大学学报(自然科学版),2003,33(4):609-614. ZHANG Aibin,WEI Jinwu,WANG Yan,et al.Determination of impurity elements in high purity graphite ash by equential scan inductively coupled plasma atomic emission spectrometry[J].Periodical of Ocean University of China,2003,33(4):609-614. [8] 刘欣丽,段太成,韩熠,等.悬浮进样-电感耦合等离子体质谱水溶液校正法测定高纯石墨中的超痕量硼[J].分析化学,2010,38(5):693-696. LIU Xinli,DUAN Taicheng,HAN Yi,et,al.Slurry nebulization-inductively coupled plasma mass spectrometry with solution calibration for determination of ultra-trace boron in high pure nuclear graphite powder[J].Chinese Journal of Chemistry Research,2010,38(5):693-696. [9] 任婷,赵丽娇,曹珺,等.高分辨连续光源石墨炉原子吸收光谱法测定食品中铅、镉和铬含量[J].光谱学与光谱分析,2012,32(9):2566-2571. REN Ting,ZHAO Lijiao,CAO Jun,et,al.Determination of Pb,Cd and Cr in food by high resolution continuum source graphite furnace atomic absorption spectrometry[J].Spectroscopy and Spectral Analysis,2012,32(9):2566-2571. [10] 工业和信息化部.YS/T 37.5—2018 高纯二氧化锗化学分析方法:石墨炉原子吸收光谱法测定铁量[S].北京:冶金工业出版社,2018. [11] 工业和信息化部.YS/T 37.3-2018 高纯二氧化锗化学分析方法:石墨炉原子吸收光谱法测定砷量[S]. 北京:冶金工业出版社,2018. [12] 乐爱山,赵收创,何学文,等.石墨炉原子吸收光谱法测定高纯二硫化钼中铜铅[J].冶金分析,2004,24(3):51-53. LE Aishan,ZHAO Shouchuang,HE Xuewen,et,al.Determination of copper and lead in high-purity molybdenum disulfide by GFAAS[J].Metallurgical Analysis,2004,24(3):51-53. [13] 高燕,刘英.石墨炉原子吸收法测定高纯硒中痕量铁[J].分析试验室,2007(3):26-29. GAO Yan,LIU Ying.Determination of trace iron in high-purity selenium by GFAAS[J].Chinese Journal of Analysis Laboratory,2007(3):26-29. [14] 李奋,吴文启,谢晓雁,等.离子交换分离石墨炉原子吸收光谱法测定高纯铟中痕量铅[J].冶金分析,2013,33(12):19-23. LI Fen,WU Wenqi,XIE Xiaoyan,et,al.Determination of trace lead in high purity indium by graphite furnance atomic absorption specrometry after ion-exchange separation[J].Metallurgical Analysis,2013,33(12):19-23. [15] 王征,赵学玒,孙传强,等.电感耦合等离子体质谱法测定痕量铁元素时碰撞反应池条件的探讨[J].冶金分析,2015,35(6):1-7. WANG Zheng,ZHAO Xuehong,SUN Chuanqiang,et,al.Discussion on collision/reaction cell conditions for determination of trace iron by inductively coupled plasma mass spectrometry[J].Metallurgical Analysis,2015,35(6):1-7.
