双波长吸光光度法测定磷矿中氧化镁

DW-ABSORPTIOPHOTOMETRIC DETERMINATION OF MAGNESIUM OXIDE IN PHOSPHATE ROCK

以EGTA Ba和SO2 - 4为联合掩蔽体系 ,有效地消除因大量钙存在而产生的干扰。在pH10 .2硼砂缓冲溶液中 ,镁与偶氮氯膦Ⅰ形成稳定络合物 ,用自制的双波长分光光度仪 ,在组合波长5 70nm和 5 0 0nm下 ,用于磷矿中镁的测定 ,不需分离 ,方法简单、快速 。

The DW absorptiophotometric method for the determination of magnesium oxide in phosphate rock was described. The chromogenic reaction of Mg(Ⅱ) with CPA Ⅰ was carried out in a borate buffer medium of pH 10.2, and solutions of EGTA Ba and Na 2SO 4 were added to mask calcium(Ⅱ) ion. The dual wavelength photometric measurements were made on a self made, simple constructed DW spectrophotometer. The measuring wavelength was set at 570nm and 500nm was chosen as the reference wavelength. The proposed method was proved to be simple, rapid and accurate.