Green chemistry: magnetic dispersive solid phase extraction for simultaneous enrichment and determination of V, Ni, Ti and Ga in water samples by HR-CS ETAAS.

This work presents a straightforward, highly sensitive, and cost-effective method for the simultaneous determination of V, Ti, Ni and Ga by high resolution-continuum source electrothermal atomic absorption spectrometer (HR-CS ETAAS) in aqueous environmental samples (tap and seawater samples). The system is based on retention of the analyte onto a novel magnetic nanomaterial (M@GO magnetic graphene oxide) functionalised with methylthiosalicilate (MTS). The formed complexes between the M@GO-MTS and the target analytes were broken, adding 1 mL of nitric acid (6%) and sonication for 5 min. The optimized method achieved detection limits of 0.71 μg L^-1 for Ti, 0.20 μg L^-1 for V, 0.04 μg L^-1 for Ga, 0.66 μg L^-1 for Ni. The accuracy of the proposed method was demonstrated by analysing two certified reference materials and by determining the analyte content in spiked environmental water samples. The results obtained using this method were in good agreement with the certified values of the standard reference materials, and the recoveries for the spiked tap water and seawater samples ranged from 94% to 120%.