title: A microassay for serum dialyzable calcium and magnesium by ion chromatography.
abstract: We describe a method for determining dialyzable calcium and dialyzable magnesium in 50-microliter volumes of routinely handled aerobic serum. Calcium and magnesium concentrations were measured by ion chromatography after a 1-min equilibrium dialysis. Day-to-day precision (coefficient of variation, CV) was 3.8% for dialyzable calcium and 4.5% for dialyzable magnesium. Dilution of serum with water 1:1 as well as storage at 4 or -20 degrees C had no significant effects. Reference intervals for dialyzable calcium (58.1-68.1 mg/l) and magnesium (12.3-17.1 mg/l) were determined for 26 healthy adults. Lack of interference and the ability to determine simultaneously several analytes on a single specimen are advantages of the chromatographic method.
mesh_terms: D000328:Adult; D000332:Aerobiosis; D000693:Anaerobiosis; D002118:Calcium / Q000097:blood*; D002245:Carbon Dioxide / Q000032:analysis; D002852:Chromatography, Ion Exchange / Q000379:methods; D003956:Dialysis; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000097:blood*; D008297:Male; D008832:Microchemistry / Q000379:methods; D012016:Reference Values; D014462:Ultrafiltration / Q000379:methods
chemical_list: D002245:Carbon Dioxide; D008274:Magnesium; D002118:Calcium