Applying poly-dopamine coated on chromorpb-p as a simple and efficient solid phase extraction adsorbent for preconcentration of Pb, Cu, Zn and Co in industrial water samples

In this study, we reported the application of poly dopamine coated on chromosorb-p as new and efficient sorbent for extraction and preconcentration of Pb, Cu, Co, and Zn ions in water samples[1,2,3].The extracted metals ions were then eluted and determined by a flame atomic absorption spectrometer. An aqueous solution of dopamine was polymerized in 0.01 mol L-1 TRIS for 12 h and simultaneously coated on the chromosorb-p particles. During the process, the colour of the chromosob-p particles was turned from the orange to dark-brown, indicating the successful coating by poly-dopamine[1,3]. The structural characterization of the adsorbent was conducted by Fourier transform infrared (FT_IR), SEM (scanning electron microscopy), which confirmed the successful coating poly dopamine on choromsorb_P and the adsorbent contains a porous structure[3]. The effect of key parameters affecting the preconcentration and elution of the analytes such as the amount of the adsorbent conditions, pH of sample, type and volume of eluent, and the effect of electrolytes on extraction recoveries were studied. In addition, the effect of interfering ions that commonly found in industrial waters were examined, and no serious interference was observed from the studied ions. Under optimal conditions the recoveries of the analytes were ranged from 85%to 98%. The calibration plot was linear from 10 to 500 ng mL-1 with the correlation coefficients better than 0.996. The precisions of the extractions, based on relative standard deviation (RSD%, n=5) at two different concentrations levels were in the range of 2.15% to 6.27%. The limits of detection (LODs) of the analytes, based on a signal-to-noise ratio (S/N = 3) were ranged from 0.89 ng mL-1 to 22.31 ng mL-1. The ability of this adsorbent for extraction and preconcentration of the studied analytes was studied in different industrial wastewater samples. The recoveries of the spiked analytes in the real samples were in the range of 82% to 95%. The results showed that method obviously had a large potential for preconcentration and determination of heavy metals in industrial water samples.