Determination of calcium and magnesium in serum, urine, diet, and stool by atomic absorption spectrophotometry.

ATOMIC ABSORPTION was developed by Walsh and his associates (1) as an analytical technic applicable to the determination of many metals. Willis (2-4) found that this technic was applicable in particular to tile determination of calcium and magnesium in Serum and urine. These published results indicated that atomic absorption spectrophotometry would be a simple, rapid, and practical method for tile determination of calcium and magnesium in biologic material, particularly in serum and urine, and that it could be adapted effectively to the needs of a clinical chemistry laboratory. After evaluation, we have used atomic absorption spectrophotometry for routine determinat ion of calcium and magnesium iii serum and urine since November 1962. Since our studies of this technic began, several reports have appeared on the determination of calcium and magnesium in biologic materials (5-12), indicating considerable variation in tile methods used. Thus, it seems appropriate to publish the procedures we have found useful for routine determinations of these elements, not only in serum and urine, but also in diet and stool.