Abstract:

A new method for the determination of trace Pb2+ by flame atomic absorption spectrometry(FAAS) after separation and preconcentration with molecular imprinting of chitosan/attapulgite（MICA） has been established. Under dynamic condition, the optimal pH of the solution, flow rate, elution conditions were obtained for preconcentration of trace Pb2+. And the effect of interfering ions was also investigated. It was found that Pb2+ could be quantitatively preconcentrated on MICA at pH=4.5. The flow rates of sample solutions and eluting solution with 1.0 mol/L HCl-0.1 mol/L methyl isobutyl ketone alcohol were 0.60 mL/min and 0.96 mL/min, respectively. The dynamic adsorption capacity of Pb2+ on MICA was 36.78 mg/g. The linear range for Pb2+ was 0~1.28 mg/L, correlation coefficient was 0.999 7, detection limit(3σ, n=11) for Pb2+ was 0.73 μg/L, and the relative standard deviation was 1.69%(n=6, ρ=0.08 mg/L), the recovery was in the range of 98.7%~101.4%. The method is convenient, highly precise and linear in a wide range. The method has been applied to the determination of trace amount Pb2+ in water samples with satisfactory results.

Key words: Molecular imprinting Technique, Attapulgite, Chitosan, Separation and preconcentration, FAAS, Pb2+