Preconcentration of trace amounts of copper(II) on octadecyl silica membrane disks modified with indane-1,2,3-trione 1,2-dioxime prior to its determination by flame atomic absorption spectrometry

Background: Oximes are a group of complexing agents with good affinity towards transition metal ions; The major advantages of SPE disks are: faster sample processing due to the high cross sectional area of the disk and decrease in pressure drop, allowing higher sample flow rates; less chance of plugging by particulate matter due to wide bed; reduced channeling and improved mass transfer because of small packing particles. Context and purpose: Indane-1,2,3-trione 1,2-dioxime was used as complexing agent for the preconcentration of trace amounts of Cu(II) ions from aqueous samples by modifying octadecyl silica membrane disks prior to determination by flame atomic absorption spectrometry. Results: The influence of analytical parameters including pH and flow rate of sample solution, amounts of complexing agent, and type and flow rate of eluent for the stripping of Cu(II) from the disks were investigated. Main findings: The proposed method had a linear range of 5.0 to 500 ng mL^−1. The limit of detection of the method was 0.2 ng mL^−1, and an enrichment factor of 200 was obtained. Conclusion: The proposed method has been applied to the determination of copper in several aqueous samples with satisfactory results.