Abstract:

A new method for the determination of Pb2+ in environmental water sample using crosslinked polyacrylonitrile as a solidphase extractant and flame atomic absorption spectrometry(FAAS) as a sensitive detector has been developed. The adsorption of Pb2+ by crossslinked polyacrylonitrile and factors affecting the adsorption capacity were studied by AAS. The experimental results showed that at optimal adsorption conditions, e.g., pH of adsorbate solution was 5.4, static adsorption time was 1.5 h and adsorption procedure was carried at room temperature, polyacrylonitrile as adsorbent has high adsorption capacity for Pb2+ which can reach 49.6 mg/g. Adsorption rate was 90% during the 1.5 h static adsorption time. Using 0.10 mol/L chloride acid as the desorption solvent to desorb the adsorbates, the enrichment factor and the recovery were 50 times and 97% respectively. Under enrichment factor of 50 times, the detection limits(3σ) was 5.3 μg/L and the relative standard deviation(RSD) was 2.1%. The established method was extended to the determination of environmental samples and the results were satisfactory(recovery was 92.9%～97.6%). These results indicate that the polymer has good regenerate capability.

Key words: polyacrylonitrile, adsorption, lead, atomic absorption spectrometry