title: Infinite dilution conductimetry of plasma and urine: correlation with osmolality.
abstract: The infinite dilution conductivity (IDC) of plasma and urine allows a measurement of the electrolyte content in small samples (5 to 15 microliter). The method was compared to the corrected osmolality (II'p) measured by the freezing-point depression. A linear correlation existed between II'p and the IDC: for plasma: II'p = 13.10 sigma o,p + 37.00 (n = 46 and r = 0.9949) for urine: II'u = 12.75 sigma o,u + 16.56 (n = 85 and r = 0.9504). The measurement of the IDC does not depend on protein concentration and can be used instead of the osmometer methods to determine the total plasma and urine electrolyte content.
mesh_terms: D001790:Blood Physiological Phenomena; D003217:Conductometry / Q000379:methods*; D004553:Electric Conductivity; D004573:Electrolytes / Q000097:blood; D006801:Humans; D009994:Osmolar Concentration; D014556:Urine / Q000502:physiology*
chemical_list: D004573:Electrolytes