Calcium, Random Urine

Additional Information:

UFHPL Epic order code: LAB371

CPT Code(s):


Specimen Requirements:

Type: Urine, random

Container/Tube: Plastic urine container with no preservative

Sample Volume: 1 mL

Storage: Refrigerate specimens.

Specimen Retention Time: 5 days


This calcium procedure is based on calcium ions (Ca2+) reacting with Arsenazo III (2,2’-[1,8-Dihydroxy-3,6-disulphonaphthylene-2,7-bisazo]- bisbenzenear-sonic acid) to form an intense purple-colored complex.2,3 Magnesium does not significantly interfere in calcium determination using Arsenazo III. In this method the absorbance of the Ca-Arsenazo III complex is measured bichromatically at 660/700 nm. The resulting increase in absorbance of the reaction mixture is directly proportional to the calcium concentration in the sample. (Package Insert: OSR General Chemistry BAOSR6x117.05, 2014-04)


Within 24 hours

Reference Values:

No reference range established