熔融制样-X射线荧光光谱法测定磷铁中磷硅锰钛

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

使用熔融制样-X射线荧光光谱法(XRF)测定磷铁合金样品,关键是要解决样品前处理中合金样品侵蚀铂-黄坩埚的难题。采用陶瓷坩埚石墨垫底低温预氧化后,高温熔融制样,建立了X射线荧光光谱测定磷铁中磷、硅、锰和钛的方法。选用磷铁标准样品,按照一定的比例合成及在磷铁标准样品中加入标准溶液的方式,配制成一定梯度的磷铁校准样品,拓宽了校准曲线的含量范围。以碳酸锂和过氧化钡复合氧化剂,从400℃缓慢升温至800℃,对磷铁样品进行预氧化,避免了熔融过程中对铂-黄坩埚的腐蚀。实验结果表明,以四硼酸锂为熔剂,溴化铵溶液为脱模剂,稀释比40∶1,于1100℃下熔融20 min,制得的玻璃熔片均匀稳定。各元素的检出限为32.47~57.49μg/g。在最佳实验条件下对磷铁标准样品进行测定,各元素测定结果的相对标准偏差(RSD,n=10)为0.28%~1.1%。实验方法应用于磷铁实际样品的测定,与其他方法的测量结果无显著性差异。

During the determination of ferrophosphorus sample by X-ray fluorescence spectrometry(XRF)with fusion sample preparation,the key is to solve the problem of platinum-gold crucible corrosion in alloy sample pretreatment.The sample was firstly pre-oxidized at low temperature in ceramic ruthenium with graphite on the bottom and then mused at high temperature for sample preparation.A method for determination of phosphorus,silicon,manganese and titanium in ferrophosphorus by X-ray fluorescence spectrometry was established.The calibration samples of ferrophosphorus with certain content gradient were prepared using certified reference materials of ferrophosphorus according to a certain ratio as well as adding standard solution.The content range of calibration curves was broadened.Lithium carbonate and ruthenium peroxide composite oxidant were used to pre-oxidize the ferrophosphorus samples by slowly increasing the temperature from 400℃to 800℃,avoiding the corrosion of platinum-gold crucible in sample melting process.The experimental results showed that the prepared glass pieces were uniform and stable under the following conditions:lithium tetraborate was selected as the flux;ammonium bromide solution was selected as the release agent;the dilution ratio was 40∶1;the melting temperature was 1100℃and the melting time was 20 min.The limits of detection for elements were between 32.47μg/g and 57.49μg/g.The standard sample of ferrophosphorus was determined under the optimal experimental conditions.The relative standard deviations(RSD,n=10)of determination results were between 0.28%and 1.1%.The proposed method was applied for the determination of actual ferrophosphorus samples,and the found results had no significant difference with those obtained by other methods.