Standard anions (F^-, Cl^-, NO₂^-, Br^-, NO₃^-, HPO₄^2- and SO₄^2-) as well as carbonate were analyzed using IC I-524A (an anion analysis column for non-suppressor method). When an alkaline eluent is used, peaks of divalent cations (Mg²⁺, Ca²⁺) may interfere. In such instances, the sample must be pretreated using an Na⁺ type cation exchanger and the divalent cations in the sample replaced with Na⁺.
In case that the pH of the eluent is higher than 7.0, 10 % methanol should be added to maintain the durability of the packing material.

(Preparation of eluent)
1) Put 0.207 g of reagent grade p-hydroxybenzoic acid and 100 mL of methanol into a volumetric flask and dissolve.
2) Add pure water to make up a 900 mL solution.
3) Add 7.9 mL of 0.2 M reagent grade diethylethanolamine.
4) Add purified water to make up a 1 liter solution.
5) Pass through a 0.2 μm membrane filter before use.

(Remark): 0.2 M diethylethanolamine should be kept in a refrigerator.
 

Sample : 20 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. HPO42- 10 mg/L 8. SO42- 10 mg/L

AsO43- 50 mg/L I- 50 mg/L CrO42- 50 mg/L S2O32- 50 mg/L WO42- 50 mg/L MoO42- 50 mg/L SCN- 50 mg/L

Column       : Shodex IC I-524A (4.6 mm I.D. x 100 mm)
Eluent       : 1.5 mM p-Hydroxybenzoic acid (pH7.8 adjusted with N,N-Diethylethanolamine)
               + 10 % CH3OH
Flow rate    : 1.2 mL/min
Detector     : Non-suppressed coductivity
Column temp. : 40 °C