Thiol modified Au nanoparticles grafted manganese doped magnetic iron oxide nanoparticles for spectrometric determination of short-term release of mercury and copper from dental amalgam in saliva

A new adsorbent, ethylene glycol bisthioglycolate modified gold nanoparticles grafted Mn doped Fe3O4 nanoparticles (EGBTG-Au@Mn-Fe3O4 NPs) were synthesized through chemical precipitation followed by an oxidative Mn doping process to use for extraction and preconcentration of trace amounts of Hg, and Cu ions in artificial and natural saliva. The prepared adsorbent was characterized by TEM, BET, XRD and VSM techniques. Fusayama artificial saliva was prepared and used as blank sample and natural saliva was collected from nine volunteers ranged from 15-29 years old who exposed to posterior decayed teeth amalgam filling and short-term release of heavy metal ions was assessed in 24, 72 and 96 h after filling. Various factors affecting extraction/desorption efficiency of target ions have been investigated and analytical characteristics of the recommended method were determined. Detection limits of 0.12 and 0.09 ng mL-1 were obtained for Cu and Hg ions respectively with preconcentration factor of 96. The results revealed that the adsorbent has high adsorbent capacity and good reusability for extraction/preconcentration of target ions in relatively high saline solution like biological fluids.