The determination of calcium in plasma and urine

Calcium is determined in plasma following a fifty-fold dilution with lanthanum chloride. 

Intermediate standard Ca 10mg% — dilute 10 ml of stock standard to 100 ml with 140 meq Na, 5 meq K l-1 solution. 

Working standard dilute the calcium 10mg% solution fifty-fold with lanthanum diluent. 

Take an appropriate volume of plasma and dilute fifty-fold with lanthanum diluent. For the determination of calcium in urine the sample should be diluted with lanthanum chloride to produce a concentration of about 100 mg/100 ml. 

---