惰气熔融法测定镁中氧、氢、氮

摘要

惰气熔融法定量分析镁中气体含量必须结合合适的浴料/助熔剂,氧、氢和氮分别测定,才能有效地减少镁挥发物对分析结果的干扰,实现定量准确测定.应用特制的Sn-Ni-FeCu-C五元浴测定纯镁粉、镁-铝粉、镁粒和镁锭样品中氧含量,相对标准偏差(RSD,n=3)小于31.5％；用纯物质Mg(OH)2标定时,氧的回收率达97.1％.应用锡助熔剂/浴料结合较低的分析功率测定纯镁粉、镁-铝粉和镁锭中氢,相对标准偏差(RSD,n=6)小于35.7％,采用Mg(OH)2标定,氢的回收率达96.9％.应用镍助熔剂测定纯镁粉、镁-铝粉和镁锭中氮,相对标准偏差(RSD,n=3)小于23.6％,采用纯物质Mg3 N2标定,氮的回收率达99.2％.应用钢标祥监控镁污染情况,确保镁中气体分析数据的可靠性.%In quantitative analysis of gases content in magnesium by inert gas fusion method, accurate determination could be realized by eliminating the interference of magnesium volatile matters through separate determination of oxygen, hydrogen,and nitrogen with combination of proper bath material and flux. In this paper, the content of oxygen in pure magnesium powder, magnesium-aluminum powder, magnesium granule and magnesium ingot samples were determined using special Sn-Ni-Fe-Cu-C quinary bath with relative standard deviation (RSD, n=3) smaller than 31. 5 %. The recovery of oxygen was up to 97. 1 % with pure Mg (OH)2 for calibration. The content of hydrogen in magnesium powder, magnesium-aluminum powder and magnesium ingot samples were determined using tin fluxing agent/bath material combining with low analytical power, and the RSD (n=6) was smaller than 35. 7 %. The recovery of hydrogen was up to 96. 9 % with Mg (OH)2 for calibration. The content of nitrogen in pure magnesium powder, magnesium-aluminum powder and magnesium ingot samples were determined using nickel fluxing agent, and the RSD (n=3) was smaller than 23. 6 %. The recovery of hydrogen was up to 99. 2 % with pure Mg3N2 for calibration. The magnesium pollution was monitored with steel certified reference materials to ensure the reliability of analytical results of gases in magnesium.