Separation and quantitation of serum constituents associated with calcium by gel filtration.
- 1 December 1976
- journal article
- research article
- Published by Oxford University Press (OUP) in Clinical Chemistry
- Vol. 22 (12), 1968-1972
- https://doi.org/10.1093/clinchem/22.12.1968
Abstract
Gel filtration of serum by use of polyacrylamide beads (Biogel P-2) separates total colcium into four distinct peaks: an initial peak, corresponding to protein-bound calcium; a second peak containing the calcium complexes of citrate, phosphate, lactate, and sulfate; a third peak containing calcium bicarbonate; and a fourth peak or trough corresponding to the serum ionic calcium. An eluent containing (per liter) 140 mmol of sodium, 1.1o mmol of calcium, 0.50 mmol of magnesium, and 10 mmol of 2-([tris(hydroxymethyl)methyl]amino)ethanesulfonic acid(pH 7.40 at 37 degrees C) provides physiological conditions that determine the equilibria between these calcium components. Association constants determined under these conditions permit calculation of the expected concentration of the calcium complexes in each tube of eluent, and these concentrations closely correspond to the amount of bound calcium measured experimentally. The mean distribution of calcium in healthy individuals, as determined by this method, is (per liter): calcium protein, 1.00 mmol; calcium complexes, 0.31 mmol; and ionic calcium, 1.07 mmol.This publication has 2 references indexed in Scilit:
- Multiple Automatic Sequential AnalysisClinical Chemistry, 1964
- ION ASSOCIATION. VI. INTERACTIONS BETWEEN CALCIUM, MAGNESIUM, INORGANIC PHOSPHATE, CITRATE AND PROTEIN IN NORMAL HUMAN PLASMA*JCI Insight, 1961