Selective extraction and preconcentration of chromium using Moringa oleifera husks as biosorbent and flame atomic absorption spectrometry

► A method for selective extraction and preconcentration of chromium is proposed. ► Moringa oleifera husks were used as natural material for solid phase extraction. ► Cr(III) and Cr(VI) were adsorbed by distinct mechanism. ► Due to the preconcentration step it was possible to obtain low limit of detection.