A new and efficient Solid Phase Microextraction approach for analysis of high fat content food samples using a matrix-compatible coating.
The current work presents the optimization of a protocol enabling direct extraction of avocado samples by a new Solid Phase Microextraction matrix compatible coating. In order to further extend the coating life time, pre-desorption and post-desorption washing steps were optimized for solvent type, time, and degree of agitation employed. Using optimized conditions, lifetime profiles of the coating related to extraction of a group of analytes bearing different physical-chemical properties were obtained. Over 80 successive extractions were carried out to establish coating efficiency using PDMS/DVB 65µm commercial coating in comparison with the PDMS/DVB/PDMS. The PDMS/DVB coating was more prone to irreversible matrix attachment on its surface, with consequent reduction of its extractive performance after 80 consecutive extractions. Conversely, the PDMS/DVB/PDMS coating showed enhanced inertness towards matrix fouling due to its outer smooth PDMS layer. This work represents the first step towards the development of robust SPME methods for quantification of contaminants in avocado as well as other fatty-based matrices, with minimal sample pre-treatment prior to extraction. In addition, an evaluation of matrix components attachment on the coating surface and related artifacts created by desorption of the coating at high temperatures in the GC-injector port, has been performed by GCxGC-ToF/MS.
Department of Chemistry, University of Waterloo, Ontario N2L 3G1, Canada; Dipartimento di Scienze del Farmaco e dei Prodotti per la Salute (SCIFAR), University of Messina, Viale Annunziata, 98168 Messina, Italy.
Selenia
S
De Grazia
Department of Chemistry, University of Waterloo, Ontario N2L 3G1, Canada.
Emanuela
E
Gionfriddo
Department of Chemistry, University of Waterloo, Ontario N2L 3G1, Canada. Electronic address: janusz@uwaterloo.ca.
Janusz
J
Pawliszyn
D004129:Dimethylpolysiloxanes; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D057230:Limit of Detection; D027421:Persea / Q000737:chemistry*; D052617:Solid Phase Microextraction / Q000379:methods*
D004129:Dimethylpolysiloxanes
Avocado; Direct immersion; Extended lifetime; Matrix-compatible SPME coating; PDMS/DVB/PDMS