电感耦合等离子体原子发射光谱法测定碳化钒中铁磷钛

准确、快速地测定碳化钒中Fe、P、Ti等杂质元素含量,对碳化钒产品质量判定意义重大。试验采用酸溶后碱熔回渣方法溶解样品,即先用王水溶解样品,再过滤,滤渣及滤纸经灰化后再用混合熔剂(碳酸钠-硼酸)熔融。采用基体匹配法绘制校准曲线消除基体效应的影响,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定Fe、P、Ti。方法中Fe、P和Ti校准曲线的线性相关系数均大于0.999,方法检出限分别为0.00036%、0.00082%和0.0012%。实验方法用于3个碳化钒实际样品中Fe、P、Ti的测定,结果的相对标准偏差(RSD,n=7)小于0.90%,加标回收率为96%~103%,测定值与其他方法(Fe采用GB/T 20255.2—2006火焰原子吸收光谱法、P采用YB/T 4566.6—2016铋磷钼蓝分光光度法、Ti采用GB/T 20255.3—2006火焰原子吸收光谱法)测定值相吻合。有效解决了碳化钒中低含量Fe、P、Ti的同时测定问题,可用于碳化钒中0.015%~0.113%Fe、0.016%~0.046%P、0.015%~0.088%Ti的测定。

Determination of iron,phosphorus and titanium in vanadium carbide by inductively coupled plasma atomic emission spectrometry

The accurate and rapid determination of impurity elements such as iron, phosphorus and titanium in vanadium carbide has great significance to judge the quality of vanadium carbide products. The sample was dissolved in experiments by acid dissolution-alkali fusion of slag. In other words, the sample was first dissolved with aqua regia. After filtration, the filter residue and filter paper were ashed and then fused with mixed flux (sodium carbonate-boric acid). The calibration curve was prepared by matrix matching method to eliminate the interference of matrix effect. The content of iron, phosphorus and titanium were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The linear correlation coefficients of calibrations curves for iron, phosphorus and titanium were all higher than 0.999. The limit of detection was 0.00036%, 0.00082% and 0.0012%, respectively. The experimental method was applied for the determination of iron, phosphorus and titanium in three actual samples of vanadium carbide. The relative standard deviations (RSD, n=7) were less than 0.90%, and the spiked recoveries were between 96% and 103%. The found results were consistent with those obtained by other methods (Fe: flame atomic absorption spectrometry in GB/T 20255.2-2006; P: bismuth-phosphorus-molybdenum blue spectrophotometry in YB/T 4566.6-2016; Ti: flame atomic absorption spectrometry in GB/T 20255.3-2006). The proposed method effectively solved the difficulty in simultaneous determination of low-content iron, phosphorus and titanium in vanadium carbide samples, and it was applicable for the determination of vanadium carbide samples with iron, phosphorus and titanium content in the range of 0.015%-0.113%, 0.016%-0.046% and 0.015%-0.088%, respectively.