RESUMO
An efficient method based on CysSB/MetSB@MWCNTs as a novel bio structure material was used for determination/separation of nickel and cobalt (Ni and Co) in human samples by ultrasound assisted-dispersive ionic liquid-suspension solid phase micro extraction (USA-DIL-SSPME). In this procedure, CysSB/MetSB@MWCNTs suspended in 1-butyl-2,3-dimethylimidazolium hexafluorophosphate ([BDMIM][PF6]) and mixture dispersed to 10 mL of blood samples at optimized pH by injecting. Then, the Co/Ni (II) was extracted with CysSB/MetSB@MWCNTs without any ligands and settled down in conical tube by IL [Ni/Coâ:SMWCNTs]. After back extraction of ions from remaining solution, the concentration of Co/Ni was determined by electro thermal atomic absorption spectrometry (ET-AAS). By optimizing, the linear range, detection limit and enrichment factor of CysSB @MWCNTs were obtained (0.1-3.4 µg L-1; 0.08-3.2 µg L-1), (0.028 µg L-1; 0.022 µg L-1) and (50.2; 48.7) for Ni and Co ions in human biological samples, respectively (RSD<5%). The adsorption capacity of CysSB@MWCNTs for Ni and Co ions was 226.7 mg g-1 and 193.3 mg g-1, respectively which was higher than MetSB@MWCNTs. The standard reference materials (NIST, SRM) and ICP-MS were used for validation of methodology.
