LAUSR

The present study describes the successful fabrication of bio-polymeric nanocomposite bead (NCB) of alginate caged magnetic graphene oxide (Alg-MGO). NCB was obtained by crosslinking of sodium alginate and calcium ions in the presence of MGO. Analytical techniques Fourier transform infra-red (FT-IR), field emission scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the Alg-MGO. Analytical application is conducted with magnetic solid phase extraction (MSPE) method for determination of Cu(II) and Pb(II) in urine, saliva and river water sample. The linear concentration range obtained were 0.33–25.00 µg L− 1 with appropriate coefficient of determination (R2 = 0.99) and low limit of detection (LOD = 0.21–0.71 µg L− 1, n = 3). The newly developed MSPE-NCB was successfully validated with standard reference material (SRM 2670a, NIST). Metal ions removal process was studied at high concentration level (1–200 mg L− 1) and isotherm models were applied. Langmuir isotherm is well fitted to experiments due to high value of coefficient of determination (R2) and proper adsorption capacity 96.13 and 103.09 mg g− 1 obtained for Cu(II) and Pb(II), respectively. Thermodynamic model is suggested spontaneous process, endothermic nature and physical sorption mechanism for uptake of selected metal ions from aqueous solution.