Abstract

A new method for separation/preconcentration of trace amounts of Cr, Cu and Pb in environmental samples by magnetic solid-phase extraction (SPE) with Bismuthiol-II-immobilized magnetic nanoparticles and their determination by ICP-OES has been developed. The separation of the target analytes from the aqueous solution containing the target analytes and Bismuthiol-II-immobilized magnetic nanoparticles was simply achieved by applying external magnetic field. Optimal experimental conditions including pH, sample volume, eluent concentration and volume and co-existing ions have been studied and established. Under the optimal experimental conditions, the detection limits for Cr, Cu and Pb with enrichment factors of 96, 95 and 87 were found to be 0.043, 0.058 and 0.085 ng mL⁻¹ and their relative standard deviations (R.S.D.s) were 3.5%, 4.6% and 3.7% (n = 5, C = 2 ng mL⁻¹), respectively. The method was validated with certified reference material (GBW50009-88) of environmental water sample and the analytical results coincided well with the certified values. Furthermore, the method was successfully applied to the determination of target analytes in river and lake water samples. Compared with established methods, the proposed method is characterized with high enrichment factor, fast separation and low detection limits.

Keywords: Separation/preconcentration; Cr, Cu and Pb; Environmental samples; Magnetic nanoparticles; Bismuthiol-II; ICP-OES

Article Outline

1. Introduction

2. Experimental

2.1. Instrumentation

2.2. Standard solution and reagents

2.3. Preparation of silica-coated magnetic nanoparticles (SCMNPs)

2.4. Preparation of Bismuthiol-II-immobilized silica-coated magnetic nanoparticles (BSCMNPs)

2.5. General procedure

2.6. Sample preparation

3. Results and discussion

3.1. Characterization of Bismuthiol-II-immobilized SCMNPs

3.2. Effect of pH

3.3. Effect of elution

3.4. Effect of sample volume

3.5. Effect of ultrasonic time

3.6. Effect of sediment time

3.7. Effect of co-existing ions

3.8. Adsorption capacity study and sorbent regeneration

3.9. Analytical performance

3.10. Analytical applications

4. Conclusion

Acknowledgements

References