熔融制样-X射线荧光光谱法测定锰铁和金属锰中锰硅磷

为了解决锰铁、金属锰等合金试样玻璃熔融制片时侵蚀铂黄坩埚的难题,实验采用四硼酸锂-碳酸锂混合熔剂、五氧化二钒氧化剂在石墨垫底瓷坩埚中高温预氧化熔融,有效避免了熔融制样过程中铂金坩埚腐蚀的问题,建立了X射线荧光光谱法(XRF)测定锰铁、金属锰中锰、硅、磷的分析方法。讨论了预氧化熔融的熔剂体系及氧化方法、试样与熔剂的稀释比,结果表明,试样与四硼酸锂-碳酸锂混合熔剂以1∶45的稀释比、以0.5mL200g/L溴化锂溶液为脱模剂,在1120℃熔融制得的玻璃片均匀、透亮、无气泡,符合测定要求。精密度和正确度试验结果显示,各元素测定结果的相对标准偏差(RSD,n=10)在0.10%~0.96%之间,结果与锰铁标准物质、金属锰内控标样认定值(参考值)相符,完全满足常规分析要求。

Determination of manganese,silicon, phosphorus in ferromanganese and manganese metal by X-ray fluorescence spectrometry with fusion sample preparation

During the glass fusion piece preparation for alloy samples such as ferromanganese and manganese metal, the platinum-gold crucible was easily corroded. Ithium tetraborate-lithium carbonate mixed flux and vanadium pentoxide oxidizer were melted for pre-oxidization at high temperature in porcelain crucible with graphite on the bottom, which could effectively avoid the corrosion problem of platinum-gold crucible in fusion sample preparation process. As a result, a determination method of manganese, silicon and phosphorus in ferromanganese and manganese metal by X-ray fluorescence spectrometry (XRF) was established. The flux system, oxidization method and the dilution ratio of sample to flux for pre-oxidization melting were discussed. The results showed that the prepared glass piece was uniform and transparent without bubbles, which could meet the determination requirements under the following conditions: the dilution ratio of sample to lithium tetraborate-lithium carbonate mixed flux was 1∶45; 0.5mL of 200g/L lithium bromide solution was used as the release agent; the fusion temperature was 1120℃. The precision and accuracy tests indicated that the relative standard deviations (RSD, n=10) of the measured results for each element were between 0.10% and 0.96%. The results were consistent with the certified values (reference values) of certified reference materials of ferromanganese and internal control reference samples of manganese metal. The proposed method could completely satisfy the requirements of routine analysis.