An on-line preconcentration system using ion-imprinted polymer for determination of bismuth in seawater employing atomic fluorescence spectrometry

This work proposes an on-line preconcentration system using ion-imprinted polymer (llP) for determination of bismuth in seawater employing atomic fluorescence spectrometry (AFS). The polymer was synthesized using 2- (5-bromo-2-pyridylazo) -5-diethylaminophenol (Br-PADAP) for complex formation, ethylene glycol dimethacrylate (EGDMA) as cross-linking reagent, methacrylic acid (AMA) reagent employed as the functional monomer and 2,2-azobisisobutyronitrile utilized as the radical initiator. The polymer was characterized employing the Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The determination of bismuth was performed employing hydride generation atomic fluorescence spectrometry (HG AFS) and the experimental conditions were optimized using a Box Behnken design involving the factors sample pH, eluent concentration and sodium tetrahydroborate concentration. So, using the optimized conditions the system allows the determination of bismuth with limits of detection and quantification of 26 and 88 ng L-1 and a preconcentration factor of 19.8. The system proposed was applied for the determination of bismuth in four seawater samples collected in Salvador City, Bahia State Brazil. The concentrations obtained varied from 0.38 to 0.45 μg L-1. The accuracy was evaluated by addition/recovery test. The recoveries found varied from 92 to 101 %.