[On-line determination of transitional metal ions by low-pressure ion chromatography with chemiluminescence...

The separation and determination of five transitional metal ions, Co2+, Cu2+, Mn2+, Fe2+ and Cr3+ by low-pressure ion chromatography with chemiluminescence detection were investigated for the first time. The separation was carried out on a C3 ion chromatographic column by using a step gradient elution with the mobile phase of oxalic acid-citric acid solution. The five transitional metal ions could be separated simultaneously. Luminol-H2O2-Mn+ system was used as the flow injection chemiluminescence analytical system. Under the optimum conditions with 0.5 mmol.L-1 luminol, 0.05 mol.L-1 H2O2 and 0.020 mol.L-1 NaOH, the linear ranges (mg.L-1) for Co2+, Cu2+, Mn2+, Fe2+ and Cr3+ were 0.001-0.1, 0.1-6, 0.06-4, 0.03-5 and 0.025-1 respectively; the detection limit (microgram.L-1) for Co2+, Cu2+, Mn2+, Fe2+ and Cr3+ were 0.85, 85, 42, 21 and 20. The present method is simple, rapid, accurate and has been successfully applied to detect Co2+ in vitamin B12 and Co2+, Cu2+, Mn2+, Fe2+ and Cr3+ in human hair sample with satisfactory results, which were in good agreement with those from atomic absorption spectrometry.