Inductively Coupled Plasma Mass Spectrometry as a Reference Method to Evaluate Serum Calcium Measurement Bias and the Commutability of Processed Materials during Routine Measurements.

Background: Measuring total serum calcium is important for the diagnosis of diseases. Currently, results from commercial kits for calcium measurement are variable. Generally, the performance of serum calcium measurements is monitored by external quality assessment (EQA) or proficiency testing schemes.