Modified surface based on magnetic nanocomposite of dithiooxamide/Fe3O4 as a sorbent for preconcentration and determination of trace amounts of copper

• Fe3O4 nano-magnetic improved by SDS/dithiooxamide.
• It can be used in both the pre-concentration function and detecting of Cu ions.
• This modified surface shows high adsorptive characteristics.
• This procedure is relatively simple, fast and imposes less test analysis expenses.

Magnetic nanocomposites surface (MNCS) which has anionic surfactant sodium dodecyl sulfate (SDS) coating and has undergone dithiooxamide treatment as the sorbent could be an easy and useful method to extract and make a pre-concentrated in detecting the copper ions before they are determined via the flame atomic absorption spectrometry (FAAS). The influences of the experimental parameters such as the pH of the sample, the type and concentration of the eluent, dithiooxamide concentration and volume, amount of sorbent and the interactions of ions with respect to the copper ion detection have been studied. The calibration graph was linear in the range of 2–600 ng ml−1 with detection limit of 0.2 ng ml−1. Relative standard deviation (RSD) for 6 replicate measurements was 1.8%. This method of detection has been applied to the determination of Cu ions at levels in real samples such as wheat flour, tomatoes, potatoes, red beans, oat, tap water, river water and sea water with satisfactory results.