3,3’一二甲基酚酞新分光光度法快速测定食品中的钙

利用钙与3．3’一二甲基酚酞在pH11的乙醇胺-硼酸缓冲溶液中的紫色反应，建立了光度快速测定食品中钙的新方法。λmax=570nm，测定的线性范围为0～10μg／6ml，ε=1.8×104，加标回收率为97．6％～101．6％，CV％约3．16％。用于食品中钙的快速测定，结果满意。

A new speictrophotometric method for rapiddetermination of calcium based on its purple color reaction with 3.3 '-Dimethy Lphenolphthalein in the presence of basic medium of ethanoamine -boric acid as buffer solution has been nivestigated.The optimum pH is 11.the λmax 570um the linear range of determination 0 ~ 10 μg/6ml and the molar absorbance coefficient ε =1 .8 x 10~4 .The percentage of recovery with standard addition is about 97.6% to 101 .6% and the coefficient of Variation of determination is about 3. 16% .This method has been found satistadory for the rapid determination of calcium in food.