Anion standards were analyzed using IC I-524A (an anion analysis column for non-suppressor method). This shows the change in column efficiency with the concentration of the sample when the injection volume is 100 μL. The column efficiency does not decrease until the sample concentration reaches 10 mg/L for Cl^- and 100 mg/L for SO₄^2-. Beyond those concentrations, HETP increases and peak becomes broad. When 1 mg/L of Cl^- is injected, there is not decreasing in column efficiency until the injection volume reaches 500 μL.


Sample :
Cl^-
SO₄^2-

HETP=(Column length)/(Theoretical plate number)

Column       : Shodex IC I-524A (4.6 mm I.D. x 100 mm)
Eluent       : 2.5 mM Phthalic acid (pH4.0 adjusted by Tris(hydroxymethyl)aminomethane)
Flow rate    : 1.2 mL/min
Detector     : Non-suppressed coductivity
Column temp. : 40 °C