差示分光光度法测量Cu30W70钨铜合金中钨的含量

采用传统的湿化学差示分光光度分析方法,研究了广泛用于军工、高压开关、电火花电极、电子封装的新型材料钨铜合金中钨含量的定量分析方法。由于该材料的耐腐蚀性,试样溶解是关键,实验表明采用盐酸+硝酸(9+1)、硫酸+磷酸(1+3)混合酸低温加热溶解,测定时加入草酸胺掩蔽铜的干扰,用硫氰酸胺显色。以Cu30W70为例用40%的钨为参比,配制一系列标准溶液制作工作曲线,钨含量在5~10μg/mL内服从比耳定律,方法的相对标准偏差(RSD)为1.6%,加标回收率为101.6%,适用于含钨45%以上的钨铜合金中钨的测定。

Determination of Tungsten Content in Tungsten Copper Alloy by Differential Spectrophotometry

The traditional wet chemical differential spectrophotometry analysis method was used to analyze tungsten in new copper alloys which were widely used in military industry, high voltage switch, edm electrode, and electronic packaging. Due to good corrosion resistance of the material, whether the samples can be dissolved is critical to wet chemical analysis. The experimental results show that in the mixture of hydrochloric acid and nitric acid （9 ＋ 1）, sulfuric acid and phosphoric acid（1 ＋ 3）, samples could be dissolved at lower temperature. When the sample was analyzed, ammonium oxalate was added to the solution in order to mask the interference from copper. Ammonium thiocyanate was used as color development agent. Taking Cu30W70 as an example, a working curve was made by testing series of standard solutions prepared using 40% of tungsten as reference. When the tungsten contents were within 5-10 μg/mL,the relationships between signals with concentrations obey the beer＇s law. The RSD of the method was 1.6% and the recovery was 101.6%. The method is suitable for determination of tungsten content in the copper tungsten alloy with the tungsten content more than 45 %.