A sensitive and simple method for the simultaneous determination of nutritionally important minerals including copper, nickel, and iron in real samples is in great demand. Atomic absorption spectrometry (AAS) coupled with a pre-concentration method is shown to be an appropriate technique for this objective. The method is based on the formation of mineral complexes by alpha-benzyl dioxime (BDO) supported on sodium dodecyl sulfate (SDS)-coated alumina. The metal contents in the complexes are eluted using 5 mL of 6 mol L-1 HNO3, and then detected by AAS at respective maximum wavelengths. In this procedure, minerals such as Cu, Ni, Pb, Co, and Fe can be analyzed in one run by carrying out the simultaneous separation and quantification of them. The low detection limit of these elements makes it a superior alternative to UV-vis and in several applications, also an alternative to ICP-MS techniques. The method has been successfully applied for these metal content evaluations in some real samples including waste water, river water, spring water, tap water, vegetable, and baking powder.