Ionized calcium in human milk determined with a calcium-selective electrode.

Ion effects in measurement of ionized calcium with a calcium-selective electrode.

We examined the performance characteristics of an improved electrode for measurement of ionized calcium (Orion Research, Inc.) with respect to interferences by Na+, K+, Li+, Mg2+, and H+, as well as the effect of changes in ionic strength and osmolality. At physiologically observed concentrations, all ions except Na+ insignificantly affected ionized-calcium measurements. The decrease in ionized...

Effect of pH and NaCl on measurements of ionized calcium in matrices of serum and human albumin with a new calcium-selective electrode.

A neutral ligand ion-exchanger type of ion-selective electrode is used in the current version of the Orion Model SS-20 calcium analyzer. We evaluated it over the pH range 4.0 to 8.5, using albumin solutions containing 150 mmol/L NaCl and pooled patients' serum. Within this pH range response was nernstian, and the relationship between potential (in millivolts) and log [Ca2+] at each pH was linea...

Ionized calcium

pH-adjusted ionized calcium

Bioavailability of calcium – comparing milk calcium with inorganic milk