https://doi.org/10.1351/goldbook.I03275
The pH value at which the net
electric charge
of an
elementary entity
is zero. pI is a commonly used symbol for this
kind-of-quantity
. It should be replaced by pH(I) because it is a pH determined under that particular condition.
Sources:
PAC, 1972, 31, 577. (Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 618 [Terms] [Paper]
PAC, 1994, 66, 891. (Quantities and units for electrophoresis in the clinical laboratory (IUPAC Recommendations 1994)) on page 894 [Terms] [Paper]