电感耦合等离子体原子发射光谱法测定V-4Cr-4Ti合金中铬和钛

作为核反应堆材料的钒铬钛合金要求严格控制成分符合V-(3%~5%)Cr-(3%～5%)Ti的比例关系,通常采用滴定法逐一测定合金组分铬、钛含量,操作繁杂周期较长。使用电感耦合等离子体原子发射光谱法(ICP-AES)测定V-4Cr-4Ti合金中铬和钛,满足快速高效同时测定钒铬钛合金中铬和钛的需要。重点研究了在钒铬钛三元合金共存体系下基体元素钒以及铬、钛相互之间的光谱干扰和基体效应,完成了对铬、钛的20余条主要谱线的光谱干扰试验和分析,最终优选了灵敏度适宜、未受共存组分光谱重叠干扰的铬、钛分析谱线;实验表明钒基体效应和连续背景叠加对测定产生正干扰,方法采用基体匹配和同步背景校正消除其影响。方法优化了仪器工作条件以及各分析谱线的积分区域、背景校正区域等检测条件。验证实验表明:铬和钛的检测范围为2.50%~6.00%,校准曲线线性相关系数大于0.9992。按照实验方法测定两个V-4Cr-4Ti合金样品中铬和钛,测定结果的相对标准偏差(RSD,n=8)小于0.70%;加标回收率为98%~102%;按照实验方法测定4个钒铬钛合金样品中铬、钛,与标准方法GB/T 4698.10—1996和YS/T 514.1—2009采用氧化还原滴定法分别测定铬和钛的测定值相吻合。

Determination of chromium and titanium in V-4Cr-4Ti alloy by inductively coupled plasma atomic emission spectrometry

The composition of vanadium-chromium-titanium alloy for nuclear reaction materials should be strictly controlled within the following proportion relationship: V-(3%-5%)Cr-(3%-5%)Ti. The content of alloying elements including chromium and titanium is usually determined one by one using titration method. The operation is complex and the analytical period is long. The determination of chromium and titanium in V-4Cr-4Ti alloy by inductively coupled plasma atomic emission spectrometry (ICP-AES) can meet the test requirements of chromium and titanium in vanadium-chromium-titanium alloy such as rapidness, high efficiency and simultaneous determination.The spectral interference and matrix effect between vanadium and chromium as well as titanium were emphatically studied in vanadium-chromium-titanium ternary alloy system. The spectral interference experiments and analysis of more than 20 major spectral lines of chromium and titanium were conducted. The analytical lines of chromium and titanium with appropriate sensitivity and no overlapping interference from the coexisting components were finally selected. The results showed that the matrix effect of vanadium and continuous background superimposition had a positive interference on the determination. The influence was eliminated by matrix matching and synchronous background correction. The proposed method optimized the working conditions of instrument and the detection conditions of analytical lines such as integral area and background correction area. The verification test indicated that the detection range of chromium and titanium was between 2.50% and 6.00%. The linear correlation coefficients of calibration curves were higher than 0.9992. The content of chromium and titanium in two V-4Cr-4Ti alloy samples was determined according to the experimental method. The relative standard deviations (RSD, n=8) of determination results were less than 0.70%. The spiked recoveries were between 98% and 102%. The proposed method was applied for the determination of chromium and titanium in four vanadium-chromium-titanium alloy samples, and the found results were consistent with those obtained by redox titration method according to standard method GB/T 4698.10-1996 and YS/T 514.1-2009.