SCR直接光度法测定镁合金中微量铍

Measurement of Micro Beryllium in Magnesium Alloy by SCR Direct Photometry

在 pH =9 6的溶液中 ,以乙二胺四乙酸二钠 (EDTA)和酒石酸钠为掩蔽剂 ,铍 (Be)与铬天青R (SCR)、溴化十六烷基三甲基胺 (CTMAB)形成三元络合物。在波长 5 5 8nm处有最大吸收 ,摩尔吸收系数ε为 3 0 6× 10 4L·mol-1·cm-1,铍量在 0～ 5 0 0 μg/ 10 0mL范围内 ,服从比耳定律 ,方法准确、可靠 ,有很好的选择性。适用范围为含铍 0 0 0 0 5 %～ 0 0 0 5 0 %。样品回收率可达 10 0 % 。

In solution of pH=9 6, by using EDTA and sodium tartrate as screening agent, beryllium and SCR, CTMAB form a triplet complex The maximum absorption is achieved with the wave length of 558nm, the mole absorption coefficient is 3 06×10 4 L·mol -1 ·cm -1 , as the beryllium content falls within 0～5 00μg/100mL, it conforms to Beer′s law, and the measuring method is accurate and reliable with good selectiveness Applicable measuring range is 0 0005%～0 0050% of beryllium content Sample recovery rate of 96 8%～103 8% can be achieved The method is suitable for measuring the micro beryllium in magnesium alloy