磷灰石中钙含量测定方法的探讨

The measurement of the content of Ca in apatite

在强碱条件下因为PO43－与Ca2＋结合生成难溶的Ca3（PO4）2，用经典方法测不出磷灰石中的钙含量。本文提出加入过量EDTA络合全部的钙，再用CaO标准溶液滴定过量的EDTA，测得准确的CaO含量。

：At the condition of strong alkali the infusible calcium phosphate can be composed by PO3－4and Ca2＋and the content of calcium cannot be measured by the tradition way． The paper indicate the new way ．The superfluous EDTA can complex all of calciumand the superfluous EDTA can be titrated by standard solution of calcium oxidethas measuring the precise content of calcium oxide．