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Simultaneous determination of gold and copper by reversed-phase high-performance liquid chromatography using online column enrichment as their syn-phenyl-2-pyridylketoximate chelates.

Gold and copper ions react with syn-phenyl-2-pyridylketoxime (PPKO) at 40 degrees C to form neutral chelates. Metal-PPKO chelates subsequently become preconcentrated on a minicolumn packed with a divinylbenzene-methacrylate copolymer. By switching the valve, these chelates are separated on the silica-based phenyl column and detected with a photometric detector. These processes occur automatically except for chelation. The results of the chelation, preconcentration, and separation conditions studies are presented. Calibration curves for Au and Cu ions are linear from nanograms per milliliter (parts per billion) to micrograms per milliliter (parts per million) in the original solution. The precision for 0.5-ppm standards of Au and Cu is 2.1 and 0.9 relative standard deviation (%), respectively. The accuracy of the present method is verified for Au and Cu based on the analysis of a standard alloy of the National Institute of Standards and Technology (NIST). The limits of detection for Au and Cu are 16.7 and 0.6 ppb, respectively. The effects of foreign ions on the determination of Au and Cu are discussed.