不同方法分解试样对电感耦合等离子体质谱测定不锈钢和高温合金中砷的影响  

Influence of decomposition methods on the determination of arsenic in stainless steel and superalloy by inductively coupled plasma mass spectrometry

作　　者：张翠敏[1] 刘正[1] 

机构地区：[1]钢铁研究总院,北京100081

出　　处：《冶金分析》2010年第6期21-26,共6页Metallurgical Analysis

摘　　要：对基于多种样品处理方法的电感耦合等离子体质谱(ICP-MS)测定不锈钢及高温合金中砷进行了研究。Ar与溶样酸中Cl-形成的40Ar35Cl+对砷产生重叠谱峰干扰,优化仪器参数使得As的信号-空白比与信号-干扰比最大。样品只用盐酸、硝酸分解,采用化学计量校正和理论推导校正两种方式校正Cl-干扰均可得到较好的结果;Cl-对As的干扰当量超过As含量较多时(10倍以上),源于干扰的校正结果不确定度分量显著;测试溶液中Cl-含量增加使得方法的检出限和测定下限变差。但采用稀硫酸溶解并冒烟分解和盐酸硝酸溶解-硫酸冒烟联合分解两种方法分解样品,完全消除了40Ar35Cl+多原子离子干扰,方法测定结果准确可靠,检出限(3σ)和测定下限(10σ)分别为0.00002%和0.00007%。The determination of arsenic in stainless steel and superalloy was conducted by inductively coupled plasma mass spectrometry （ICP-MS） based on a variety of sample decomposition methods in this paper. The 40Ar35Cl＋ formed by Ar and Cl-in hydrochloric acid had spectral overlapping interference with the determination of arsenic. Parameters of instrument were optimized to obtain the maximum ratio As signal to blank and As signal to interference.When the sample was decomposed with hydrochloric acid and nitric acid, the correction results of Cl-interference by stoichiometric method and theoretical derivation were both good. When the interference equivalent of Cl-to As exceeded much higher than As content （above 10-fold）, the uncertainty component of correction results from interference was significant. The increase of Cl-content in test solution deteriorated the detection limit and the lower limit of quantitation. However, when the sample was dissolved by diluted sulphuric acid or hydrochloric acid-nitric acid firstly and continued to fume with sulfuric acid, the interference of polyatomic ion （40Ar35Cl＋） could be fully eliminated. The determination results were accurate and reliable with detection limit （3 σ） of 0.000 02 % and lower limit （10 σ） of quantitation of 0.000 07 %, respectively.

关 键 词：电感耦合等离子体质谱 砷 不锈钢 高温合金 干扰校正 

分 类 号：TG115.3[金属学及工艺—物理冶金]