Fig. 3. Chromatograms of 10 μg L−1 Cr(III)-PDCA and Cr(VI) for m/z 52, using a pH 6.80 mobile phase and a flow rate of 0.5 mL min−1 (light gray), 0.6 mL min−1 (gray), and 0.7 mL min−1 (black) with the chromatogram of 210 mg L−1 Cl for m/z 35 at a flow rate of 0.6 mL min−1 (gray). PDCA, 2,6-pyridinedicarboxylic acid.
