Anion standards were analyzed using IC I-524A. This eluent is suited to the separation of three kinds of acids, phosphoric acid(H₂PO₄^-), pyrophosphoric acid(H₂P₂O₇^2-) and tripolyphosphoric acid(H₃P₃O₁₀^2-). EDTA-2Na is added to prevent the complexation of ferrous ion with polyphosphoric acids.


Sample : 50 μL
1. H₂PO₄^- 20 mg/L
2. H₂P₂O₇^2- 50 mg/L
3. H₃P₃O₁₀^2- 50 mg/L

Column       : Shodex IC I-524A (4.6 mm I.D. x 100 mm)
Eluent       : 5 mM Trimesic acid + 0.04 mM EDTA-2Na
Flow rate    : 1.2 mL/min
Detector     : Non-suppressed conductivity
Column temp. : 40 °C