2,6-pyridinedicarboxylic acid as an eluent for UV and conductivity detection of inorganic anions, magnesium and calcium in water by ion chromatography

2,6-Pyridinedicarboxylic acid (2,6-PDC) was investigated as an eluent for ion chromatographic (IC) separation of inorganic anions, Mg2+ and Ca2+ followed by UV and conductivity detection. Other eluents containing trimesic, pyromellitic and commonly used gluconate/borate were also studied. Eluents containing 2, 6-PDC gave reasonable resolution and detection sensitivity for all analytes of interest. The effects of eluent pH and concentration of 2,6-PDC on the retention and sensitivity were investigated systematically. The separation and detection of HCO3-, H2PO4-, Cl-, NO2-, NO3-, SO42-, Mg2+ and Ca2+ within 11 minutes were performed using 1 mM 2,6-PDC at pH 6.0. Detection limits were in the range 5-15 mu M for UV detection and 1.5-4 mu M for conductivity detection. The proposed method offers a quick, sensitive and simple means for the determination of common anions, Mg2+ and Ca2+ particulaly in water samples.