ABSTRACT
A sensitive, selective, and solvent-free method based on direct immersion solid-phase microextraction (DI-SPME) followed by gas chromatography with mass spectrometry (GC-MS) is proposed for the determination of trace amounts of famoxadone in wines, fruits, and vegetables. Parameters affecting the sample enrichment step, such as sample mass, ionic strength, adsorption and desorption times, and temperatures were carefully optimized. A polar 85 µm polyacrylate fiber was found to be suitable for extraction at 60°C in 20 min under continuous stirring. Desorption was carried out at 270°C for 5 min. Undiluted wine samples and diluted extracts obtained from the solid samples submitted to an ultrasound treatment in the presence of ethanol were quantified against external aqueous standards prepared in 12% ethanol (v/v). Under the optimized conditions, detection limits of 5 ng L−1 and 10 pg g−1 were obtained for liquid and solid samples, respectively. SPME-GC-MS analysis yielded good repeatability (RSD under 10% in all cases). The method provided recoveries of 91.6–110.9% from spiked samples. The method was applied to different samples, and none of them was found to contain famoxadone at concentrations above the corresponding detection limits.
ACKNOWLEDGMENTS
The authors are grateful to Comunidad Autónoma de la Región de Murcia (CARM, Fundación Séneca, Project 02993/PI/05) and to the Spanish Ministerio de Educación y Ciencia, MEC (Project CTQ2006-08037/BQU) for financial support. N. Aguinaga also acknowledges a fellowhip from CajaMurcia, Spain.
Notes
a Mean value ± standard deviation (N = 5).
a Mean ± standard deviation (N = 5).
b Solid samples.
a Mean value ± standard deviation (N = 3).
An invited paper submitted to a special issue on Green Spectroscopy and Analytical Techniques, organized by Professor Miguel de la Guardia, of the Department of Chemistry, University of Valencia, Spain, and Professor Arabinda Kumar Das, of the Department of Chemistry, University of Burdwan, West Bengal, India.