Graphene oxide/Fe3O4@β-lactoglobulin nanocomposite for the enrichment of trace Pb(II) from real samples

A new GO/Fe3O4@beta-lactoglobulin sorbent was prepared for selective extraction of trace Pb(II). The GO/ Fe3O4@beta-lactoglobulin packed column advantageously permeates samples faster than nascent GO column ca. 5 fold. We experimentally demonstrated the developed SPE method for the enrichment of Pb(II) from real samples (tap, river and packaged drinking water) before ICP-OES determination. The sulfhydryl groups of the vicinal cysteine and the carboxylic groups were led to successful chelate formation with Pb(II) ions. The method shows a detection limit of 0.30 ng mL-1 for Pb(II) ion. The prepared sorbent has a surface area and pore volume of 1460.37 m2g- 1 and 1.36 ccg- 1, respectively. The preconcentration limit and preconcentration factor for Pb(II) was found to be 0.37 mu g L-1 and 900, respectively using 3 mL of eluent. At 95% confidence level, the Student's ttest was less than the critical Student's t value (4.303). A coefficients of variation for five replicate measurements is 3.45%, indicates good precision of the method.