Thin film solid phase microextraction (TF-SPME) – utility of novel SPME geometry in food analysis

Description:
A novel carbon mesh thin film-solid phase microextraction (TF-SPME) combined with thermal desorption in gas chromatography was found to be a new, promising tool in volatiles analysis. So far, the most popular SPME device in odorants analysis are fibers, which gained popularity, mostly due to robustness, selectivity, sensitivity, and the possibility of automation. However, some issues related to this technique were reported, such as the tendency for polar analytes to be replaced by a high abundance of non-polar substances when solid sorbents are used. This problem has mainly been observed in food sample analyses, as the majority of matrices used in these studies are highly complex, and contain high concentrations of non-polar substances. TF-SPME devices will be demonstrated as a tool able to overcome the issue. For two reasons, firstly larger capacity allows for the extraction of more compounds, therefore overcoming the issue itself. Secondly, the idea of sequential extraction by PDMS and PDMS/HLB thin films will be presented. The idea of experiments involving TF-SPME was performed on an odorants mixture and then it was tested on beer samples. This technique showed a promising result not only in terms of competition phenomena prevention but also in terms of recovery and sensitivity.
Another utility of TF-SPME in combination with the thermal desorption unit is the analysis of odor-active compounds in sparkling beverages. The idea behind the experiment was to compare the content of the aroma-active substance in the gas phase by TF-SPME with the amount of droplet-bound odorants extracted filter from pyrolyzed polyacrylonitrile fiber packed in the thermal desorption unit liner. The results showed the significance of droplet-bound odorants in the creation of aroma of the carbonated beverages, which is often overlooked in studies focused on flavor creation.

Speaker: Martyna Wieczorek - University of Waterloo
Martyna Wieczorek received her Ph.D. in Food Sciences in 2020, specializing in analysis of odorants in food products. Her research focused mainly on using SPME, as well as exhaustive extraction methods in combination with gas chromatography (GCxGC-ToFMS, GC-MS/MS, GC-MS, GC-O) for analyzing odour active substances in food products. Latter research involved also liquid chromatography for the analysis of taste active compounds. After defending her Ph.D. she was working as a Postdoctoral Fellow at the University of Waterloo in Professor Pawliszyn's team. During her work in Waterloo, she was mainly focused on the application of TF-SPME devices in combination with TDU-GC-MS for comprehensive analysis of odorants in beer and other food matrices. Currently, she is working at Poznan University of Life Sciences (Poznan, Poland) and she continuing her research on implementing TF-SPME technology in the food science field.