title: Optimized atomic absorption spectrophotometry of calcium in erythrocytes.
abstract: We sought to establish optimum conditions for measuring calcium in erythrocytes by atomic absorption spectrophotometry. The conditions we selected are as follows. Wash one volume of fresh heparin-treated packed cells once with 30 volumes of isotonic buffered saline (pH 7.4) at a temperature somewhat exceeding 25 degrees C. Dilute the washed packed cells 10-fold with 12 mmol/L hydrochloric acid, and analyze the supernate for calcium. Measure the hematocrit of the washed packed cells, then analyze an aliquot of them for calcium, using a computer-readout type of flame or a non-flame atomic absorption spectrophotometer equipped with a pyrocoated graphite tube. The temperature program is 1000 degrees C for ashing [corrected] and 1800 degrees C for the atomizing cycle. Intraday and day-to-day reproducibility of the assay was 6.55% and 8.19%, respectively, at the mean concentration of calcium in the erythrocytes of healthy adults, which is 4.30 mumol/L.
authors: Division of Clinical Chemistry, School of Medical Technology, University of Shinshu, Matsumoto, Japan.
authors: S
authors: S
authors: Nomoto
authors: S
authors: S
authors: Shoji
mesh_terms: D000328:Adult; D001800:Blood Specimen Collection; D002118:Calcium / Q000097:blood*; D004912:Erythrocytes / Q000032:analysis*; D006493:Heparin; D006801:Humans; D006851:Hydrochloric Acid; D008875:Middle Aged; D012016:Reference Values; D013054:Spectrophotometry, Atomic; D013696:Temperature
chemical_list: D006493:Heparin; D006851:Hydrochloric Acid; D002118:Calcium