Anions in milk were analyzed using IC I-524A (an anion analysis column for non-suppressor method). Milk contains a considerable amount of proteins and fats, and therefore should be pretreated. 100-fold dilution with pure water was made and then treated by an solid phase extraction cartridge for reversed phase chromatography.


Sample : 100-fold diluted Milk, 50 μL
2. HCO₃^-
3. Cl^-
6. NO₃^-
7. HPO₄^2-

Sample : Anion Standards, 50 μL
1. F- 5 mg/L
2. HCO₃^- 30 mg/L
3. Cl^- 5 mg/L
4. NO₂^- 5 mg/L
5. Br^- 10 mg/L
6. NO₃^- 10 mg/L
7. HPO₄^2- 10 mg/L
8. SO₄^2- 10 mg/L

Column       : Shodex IC I-524A (4.6 mm I.D. x 100 mm)
Eluent       : 1.5 mM p-Hydoxybenzoic acid + 1.7 mM N,N-Diethylethanolamine + 10 % CH3OH
Flow rate    : 1.5 mL/min
Detector     : Non-suppressed coductivity
Column temp. : 40 °C