Microdetermination of serum calcium by parallel fast analyzer.
An adaptation of a direct microdetermination of serum calcium based upon its colored reaction product with cresolphthalein complexone for use with a parallel fast analyzer is described. It is simple, reliable and clinically accurate. Twenty microliters of sample are employed in a final volume of 650 mul. Comparison studies with an atomic absorption method resulted in a correlation coefficinet (r) of 0.94. Replicate analyses at normal (8.5 mg. per dl.) and abnormal (12.1 mg. per dl) levels showed inter-day coefficients of variation of 3.2 and 2.3%, respectively. Assays of sera of male and female donors (age range: 17--60 years) showed normal ranges of 8.5--10.8 and 8.5--10.5 mg. per dl., respectively. Moderate hemolysis and jaundice and mild lipemia are associated with spuriously high results. Magnesium in serum showed no significant effect below 4.0 mEq. per l.
D000293:Adolescent; D000328:Adult; D001322:Autoanalysis; D002118:Calcium / Q000097:blood*; D002498:Centrifugation; D003124:Colorimetry; D005260:Female; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D008832:Microchemistry / Q000295:instrumentation; D008875:Middle Aged; D013054:Spectrophotometry, Atomic
D007202:Indicators and Reagents; D002118:Calcium