Standard anions (F–, Cl–, NO2–, Br–, NO3–, HPO42- and SO42-) as well as carbonate were analyzed using IC I-524A. 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 0.207g of reagent grade p-hydroxybenzoic acid and 100mL of methanol into a messflask and dissolve.
2) Add pure water to make up a 900mL solution.
3) Add 7.9mL of 0.2M reagent grade diethylethanolamine.
4) Add purified water to make up a 1 liter solution.
5) Pass through a 0.2micron membrane filter before use.
(Remark): 0.2M diethylethanolamine should be kept in a refrigerator.
Column : Shodex IC I-524A (4.6mmID*100mm)
Eluent : 1.5mM p-Hydroxybenzoic acid(pH7.8 adjusted with N,N-Diethylethanolamine) + 10% CH3OH
Flow rate : 1.2mL/min
Detector : Non-suppressed coductivity
Column temp. : 40deg-C