3.6. Application to real samples
To demonstrate the applicability of MSPE for routine analysis,the described method was applied to the determination of EDCsin five semi-skimmed milk samples obtained from local markets.The results revealed that the selected milk samples were free fromcontamination from the target analytes.In order to evaluate the accuracy of MSPE, blank milk sampleswere fortified at a concentration level of 5 g/L and analyzed bythe proposed method, as well as by a solid-phase microextraction(SPME) adopted by Fernandez-Alvarez et al. [17]. Application ofpaired t-test at 95% confidence level showed that no significantdifference was observed between the two methods.
4. Conclusions
Functionalized MNPs were synthesized to serve as solid-phaseextraction sorbents for simultaneous enrichment and detection ofendocrine disrupting compounds in milk samples with the aid ofGC–MS. Analyte extraction and desorption were carried out quicklyand the whole pretreatment process could be accomplished bysimple vortex and ultrasonication within 25 min. The applicabil-ity, accuracy, precision, sensitivity of the proposed method havebeen demonstrated based on SANCO/12571/2013 European Guide-lines. LODs were below the MRLs set by the European Union for allcompounds studied. Considering that Fe3O4@SiO2@C18 nanoparti-cles inherit the virtues of being easy-to-prepare, cost-effectivenessand ease of separation and dispersion, this protocol is believed tobe promising for the screening of the selected compounds in milkmatrices.
Acknowledgments
This research project has been co-financed by the Euro-pean Union (European Regional Development Fund-ERDF) (MIS:348148) and Greek national funds through the Operational Pro-gram “THESSALY-MAINLAND GREECE AND EPIRUS-2007–2013” ofthe National Strategic Reference Framework (NSRF 2007–2013).The use of the XRD and SEM units of the Network ofResearch Units of the University of Ioannina and especially Dr.Papachristodoulou and Dr. Tsaousi is gratefully acknowledged.Many thanks are due to Assist. Prof. D. Petrakis for the N2adsorption–desorption porosimetry measurements.