提高快速滴定法测定生料中氧化钙准确度的措施

Measures to increase the veracity of rapid titration method for determination of CaO in raw meal

酸溶EDTA滴定法能快速测定生料中的氧化钙含量,在生产管理中可用作荧光分析测定结果的复检手段,但关键是要确保其检测的精密度和准确度。通过控制检测过程中的称量精度(采用高精度天平)和称量质量(取0.1000g),溶样时加热至沸并保持微沸2min以保证足够的溶样时间;同时EDTA标准溶液消耗量取较高量(取35ml),且CMP指示剂中的三种原料钙黄绿素、甲基百里香酚蓝、酚酞的质量配比按±0.2,±0.2和±0.1幅度变化,……就可达到绝对误差在0.10%左右、较碱熔法略低0.06%的准确测定结果。

EDTA titration can determine the CaO in raw meal rapidly and can be used as the rechecking method for fluorometric analysis when the precision and veracity guaranteed. Perfect test result of 0. 10% absolute error which slightly lower than that of 0.06% of alkaline fusion method can be realized by controlling the weighing precision（use high-precisionweighing scale and take 0.100 0 g sample） and guaranteeing enough dissolving time（when boiling then keep for 2min） and the consumption of EDTA standard solution taking 35ml and the mass error of three componets of CMP indicator calcein, methyl thymol blue eomplexon and phenolphthalein were ±0.2,±0.2 and ±0.1 respectively.