Solid phase extraction with silicon dioxide microsphere adsorbents in combination with gas chromatography-electron capture detection for the determination of DDT and its metabolites in water samples

Abstract

The goal of the present study was to investigate the feasibility of silicon dioxide (SiO₂) microspheres without special modification to enrich dichlorodiphenyltrichloroethane (DDT) and its main metabolites, p,p′-dichlorodiphenyl-2,2-dichloroethylene (p,p′-DDD) and p,p′-dichlorodiphenyldichloroethylene (DDE) in combination with gas chromatography-electron-capture detection. The experimental results indicated that an excellent linear relationship between the recoveries and the concentrations of DDT and its main metabolites was obtained in the range of 0.2–30 ng mL⁻¹ and the correlation coefficients were in the range of 99.96–99.99%. The detection limits based on the ratio of signal to the baseline noise (S/N = 3) were 2.2, 2.9, 3.8 and 4.1 ng L⁻¹ for p,p′-DDD, p,p′-DDT, o,p′-DDT, and p,p′-DDE, respectively. The precisions of the proposed method were all below 10% (n = 6). Four real water samples were utilized for validation of the proposed method, and satisfactory spiked recoveries in the range of 72.4–112.9% were achieved. These results demonstrated that the developed method was a simple, sensitive, and robust analytical method for the monitoring of pollutants in the environment.

Keywords:

• Silicon dioxide microspheres
• solid phase extraction
• organochlorine pesticides

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (20877022), Program for New Century Excellent Talents in University (NCET-10-0813), the fund from State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (No.KF2009-16), and the fund from the Henan Key Laboratory for environmental pollution control.