It is well known that ion analysis is used with conductivity detector. There are two methods for conductivity detectors: the suppressed conductivity method and the non-suppressed conductivity method. The Non-suppressed conductivity method can be easily performed by adding a conductivity detector and IC columns to any typical HPLC system.

Merit of non-suppressed method.
Since the use of a suppressor is unnecessary, the system is simple and inexpensive.

Demerit of non-suppressed method.
1. Background conductivity is rather high.
(anion analysis: 200 to 250 μS/cmFS, cation analysis: 1,000 to 2,500 μS/cmFS)
2. Sensitivity is rather low. Detection sensitivity is about tens ppb and minimum sample concentration is about hundreds ppb.
3. The usable eluent is limited to low-conductivity solvents such as phthalic acid.