固硼灰化-电感耦合等离子体原子发射光谱法测定高纯人造石墨中硼  

Determination of boron in synthetic high purity graphite by boron-fixing ashing-inductively coupled plasma atomic emission spectrometry

作　　者：周智勇 肖刘萍 涂莉娟 ZHOU Zhiyong;XIAO Liuping;TU Lijuan(National Quality Supervision and Inspection Center of Graphite Products,Chenzhou 423000,China;National Quality Supervision and Inspection Center of Precious Metals and Heavy Non-ferrous Metals Products(Hunan),Chenzhou 423000,China)

机构地区：[1]国家石墨产品质量监督检验中心,湖南郴州423000 [2]国家有色贵重金属产品质量监督检验中心(湖南),湖南郴州423000

出　　处：《中国测试》2020年第8期58-62,共5页China Measurement & Test

摘　　要：高纯人造石墨中硼含量的测定通常将试样进行直接灰化处理,在灰化过程中,表面的碳化硼与氧气反应生成致密玻璃态氧化硼包裹住未被氧化的碳化硼,阻止其持续氧化,导致结果偏低。试验采用氢氧化钙溶液预处理样品后,在800℃灰化,灰化过程中,氢氧化钙分解为氧化钙,氧化钙再与玻璃态氧化硼反应,从而使碳化硼持续氧化。灰化后用硝酸溶解,建立电感耦合等离子体原子发射光谱法测定高纯人造石墨中硼含量的分析方法。结果表明,硼质量浓度在0.02~2.0 mg/L范围内与其对应的发射光谱强度呈线性,标准曲线的相关系数为0.9999,方法检出限为0.03μg/g,测定值的变异系数(n=8)为2.5%~6.6%,加标回收率为95.2%~104.7%。The determination of boron content in high-purity artificial graphite usually involved direct ashing of the sample.During the ashing process,a dense glassy boron oxide was formed by the reaction of boron carbide and oxygen.The glassy boron oxide wraped the unoxidized boron carbide,preventing its continued oxidation,resulting in low results.After the sample was pretreated with calcium hydroxide solution,the calcium hydroxide was decomposed into calcium oxide during ashing at 800℃.The calcium oxide then reacted with the glassy boron oxide,and the boron carbide was continuously oxidized.After ashing,it was dissolved with nitric acid.A determination method for boron content in high-purity artificial graphite was established by inductively coupled plasma atomic emission spectrometry.The results showed that the mass concentration of boron was linear in the range of 0.02-2.0 mg/L,the correlation coefficient of the standard curve was 0.9999,the detection limit of the method was 0.03μg/g,the coefficient of variation(n=8)of the measured value of the sample was 2.5%-6.6%,and the recovery rate of the standard addition was 95.2%-104.7%.

关 键 词：高纯人造石墨 电感耦合等离子体原子发射光谱法 硼含量 氢氧化钙 

分 类 号：O657.3[理学—分析化学] TF031[理学—化学]