Metrohm ISE Handbuch Seite 51

4 Appendix
Ionic strength
The ionic strength I is a measure for interionic interactions in a solution.
The ionic strength depends on the concentration c and the charge z of
i i
the ions:
1
∑
2
= ⋅ ⋅
I c z
(3)
i i
2
i
TISAB
TISAB is the abbreviation of Total Ionic Strength Adjustment Buffer. A
TISAB solution is a buffer solution with high ionic strength, which fixes
the ionic strength of a sample solution as well as its pH value. TISAB
solutions are important for direct measurements using calibration
curves.
47
Ion-selective electrodes, Manual