电感耦合等离子体质谱法测定钢中痕量钙

Determination of trace calcium in steels by inductively coupled plasma mass spectrometry

微波消解钢铁样品后,以电感耦合等离子体质谱（ICP-MS）法测定试液中的痕量钙。实验中使用酸纯化器再次蒸馏的高纯酸以消除Ca的沾污,同时,分析试样前后,使用10%的盐酸对进样系统进行清洗,以去除毛细管、喷雾器和雾化室对钙的吸附。通过考察分析元素的质谱干扰情况,选择丰度高且受干扰程度较小的40Ca＋用于分析,并采用动态反应池技术消除40Ar＋对40Ca＋的质谱干扰。基体Fe的质量浓度不大于1 g/L时,Sc为内标元素可很好的校正基体效应。方法的检出限为3.18 ng/mL。以建立的分析方法对样品中钙元素含量进行了加标回收,回收率为91%～118%;对不同类型钢铁标准样品和实际样品进行分析,测定值与认定值相一致,相对标准偏差为3.5%～12%,实验结果表明该方法能够满足冶金行业对钢中痕量钙元素的测试需要。

After microwave digestion,trace calcium in sample solution was determined by inductively coupled plasma mass spectrometry（ICP-MS）.In experiments,the contamination of calcium was eliminated with high-purity acid which was redistilled in purifier.Meanwhile, the injection system was cleaned with 10 % HCl before and after analysis to remove the adsorbed calcium by capillary,nebulizer and spray chamber.By investigating the mass spectrometric interference of testing elements,the 40Ca＋ with high abundance and small interference was used for analysis.The mass spectrometric interference of 40Ar＋ to 40Ca＋ was eliminated by dynamic reaction cell technology.When the mass concentration of matrix Fe was not higher than 1 g/L,the matrix effect could be well corrected using Sc as internal standard element.The detection limit of method was 3.18 ng/mL.The recovery test of sample was conducted by the proposed method,and the recovery was 91 %-118 %.The standard and actual steel samples of different types were analyzed,and the determination results were consistent with the certified values.The relative standard deviation（RSD） was 3.5 %-12 %.The experimental results indicated that this method could meet the determination requirements of trace calcium in steel in metallurgy industry.