Ionic liquid functionlized on multiwall carbon nanotubes for nickel and lead determination in human serum and urine samples by micro solid-phase extraction

In this study, a novel synthesis adsorbent, 1-(3-aminopropyl)-3-methylimidazolium hexafluorophosphate functionlized on multiwall carbon nanotubes ([Apmim][PF6]-MWCNTs, IL@MWCNTS) was used for nickel/lead (Ni/Pb) extraction and determination by dispersive ionic liquid micro solid-phase extraction (DIL-μ-SPE) coupled to electrothermal atomic absorption spectrometry (ET-AAS). After dilution of 20 mg of IL@MWCNTS in 200 μL of acetone, the mixture was injected to 10 mL of human serum/urine samples at pH of 8.0. After sonication for 5 min, the Ni(II) / Pb(II) were extracted by ionic liquid phase and then centrifuged for 2.5 min. The upper liquid phase set aside and Ni(II) / Pb(II) loaded in adsorbent were back-extracted by acidic solution at pH=2-3. Finally, the concentration of total nickel and lead was determined by ET-AAS. By optimizing, the limit of detection, linear range, and enrichment factor for nickel and lead were obtained (0.05 μg L−1; 0.1 μg L−1), (0.2-5.8 μg L−1; 0.4-30 μg L−1) and 24.7; 5.1, respectively (RSD less than 5%). Also, the capacity absorption of IL@MWCNTS for nickel and lead ions were achieved 149.3 mg g-1 and 162.5 mg g-1, respectively. The DIL-μ-SPE procedure was validated for nickel and lead extraction by spiking of real samples and ICP-MS analyzer.