Effects of Potassium Hydroxide Concentration on Retention Time (SI-36 4D)

Please use this column with a suppressor-type ion chromatography system.

The concentration of potassium hydroxide in eluent influences the retention of each anion when analyzed by IC SI-36 4D (a column for anions analysis). The relationship between potassium hydroxide and anions’ retention time is shown below. Basically, the higher the concentration of potassium hydroxide, the faster the elution of anions. The degree of elution is different depending on anions. Especially, retention volumes of phosphate ion, sulfate ion, sulfite ion, and carbonate ion are shortened by increasing the concentration of potassium hydroxide.

Sample: 25 μL

Inorganic anions 1 μg/mL each(in H₂O)

Organic acids 10 μg/mL each (in H₂O)

Column       : Shodex IC SI-36 4D (4.0 mm I.D. x 150 mm)
Eluent       : 20, 25, 30 mM KOH aq.
               (Eluent source : DionexTM EGC 500 KOH)
Flow rate    : 0.7 mL/min
Detector     : Suppressed conductivity
Column temp. : 30 °C