Strong ion difference excess and corrected strong ion difference model incorporating the variations in apparent dissociation constant for human blood plasma electro-neutrality equilibria.

We introduce computed value of the corrected Strong Ion Difference (SID) by including the large variability of the apparent dissociation constant pK' in non-logarithmic form on SID in Henderson-Hasselbach bicarbonate ion aqueous equilibria thereby resulting in a significant correction of up to 27% in SID. We further introduce a new concept of Strong Ion Difference Excess (SIDE) as the change in SID from the reference value at pH = 7.4, pCO2 = 5.33 Kpa (or 40 torr). The SIDE is a particularly useful quick measure when one can rule out the effects of hemoglobin, weak proteins and unidentified components for human blood plasma.