Urinary calcium determination. Three newer methods compared with the Clark-Collip procedure.

OVEL METHODS for routine deterniiiiatiou of calcium in serum have widely replaced cumbersome “classic” methods. Further evaluation of the applicatioii of such methods to urine is needed. In our laboratory, urinary calcium has been measured by the accurate, but tedious, ClarkCollip procedure of precipitating calcium as the oxalate and titrating the oxalate with standardized peimangaiiate. Over the past 12 years, several other methods have been tried and found unsatisfactory for various reasons. This report compares results obtained by three adequate, newer procedures with those found by the Clark-Collip procedure. In each case, the urine specimens have a calcium content covermg the generally encountered pathologic range.