Influence of lactose on the diffusion of calcium ions at physiological temperature.

Mutual diffusion coefficients for calcium chloride (0.100 mol dm(-3)) in aqueous solutions containing lactose at various concentrations (from 0.005 to 0.200 mol dm(-3)) have been measured at 37°C (physiological temperature), by using a conductimetric cell coupled to an automatic system to follow the diffusion. This cell uses an open-ended capillary method based on the measurement of the electrical resistance of a solution placed inside the capillaries at recorded times. The analysis of the CaCl2 diffusion coefficient values obtained suggests the presence of some CaCl2/lactose aggregates in the media, which are influenced by the temperature.