Flame photometric determination of electrolytes in tissue and of calcium in serum.

The convenience and accuracy of flame photometric methods for the determination of sodium and potassium in body tissues and fluids suggest the desirability of determining other cations such as calcium and magnesium in the same sample. While reliable procedures for the determination of sodium and potassium have been developed (1, 2), there are apparently no satisfactory flame spectrophotometric methods available for the determination of calcium and magnesium in tissue. In the following, one flame photometric method is described which permits the simultaneous determination of calcium, magnesium, sodium, and potassium in tissue, and another method is described for determining calcium in blood serum.