Eluents pyridine-2,6-dicarboxylic acid/oxalic

Among many ligands used for simultaneous ion chromatography of metals, the most common eluents used are oxalic acid, tartaric acid, citric acid, 4-(2-pirydylazo)resorcinol (PAR), pyridine-2,6-dicarboxylic acid (PDCA), a-hydroxyi-sobutyric acid (HIBA), 1,2-diaminocyclohexanetetraacetic acid (DCTA), diethylenetriarninepentaacetic acid (DTPA), and ethylenediaminetetraacetic acid (EDTA). 

Other common transition metal corrosion products typically monitored at various sites within the plant include iron, copper, nickel, zinc, and chromium. More than 80% of BWR plants analyze for iron, nickel, copper, and zinc in reactor water, and nearly all of the BWR plants determine these metals in feed water. In addition, zinc is also an additive used in many plants to control the shutdown radiation dose rate. Nickel and chromium are corrosion products in BWR plants fi-om stainless-steel piping. The best selectivity and sensitivity for achieving low to submicrogram/Liter detection limits for transition metals can be obtained by separating transition metal complexes using pyridine-2, 6-dicarboxylic acid (PDCA) or oxalic acid as chelators in the eluent, followed by postcolumn derivatization with 4-(2-pyridylazo)resorcinol (PAR) and absorbance detection at 520 nm (see Section 8.2.1.2). This approach was successfully used to determine trace concentrations of iron, copper, nickel, and zinc in BWR and PWR matrices [197]. Figure 10.113 compares the chromatograms from the... 

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