Simultaneous Determination of Calcium and Magnesium of Serum by a Single Chelometric Titration

[摘要] Titration of a trichloracetic acid filtrate of serum with EDTA is carried out at pH 9.8 using an excess of Calmagite indicator. Successive photometric readings of percentage transmission, made with an EEL titrator, are plotted against the volume of EDTA added. There is very little change at first while calcium is being complexed; the reading then decreases rapidly while magnesium is being titrated, followed by a flattening of the curve at completion of the titration. Hence, two sharp "breaks" are obtained in the titration curve, the first corresponding to the amount of calcium and the second to the amount of magnesium.

[学科分类] 过敏症与临床免疫学