A comprehensive food and flavor study was recently conducted, comparing a typical high-resolution PTR-TOFMS instrument to IONICON’s ultimate-resolution trace VOC analyzer PTR-TOF 10k.
While the PTR-TOF 10k is supplied with the ioniTOF 10k platform, which facilitates mass resolutions of 10,000 – 15,000 m/Δm, the comparison apparatus was set to a more typical 5,000 m/Δm.
This study aimed to identify the primary benefits of extremely high mass resolution for food and flavor science.
The superiority of the PTR-TOF 10k was demonstrated by analysis of the complex headspace of chocolate for the presence of ethyl maltol (C7H8O3.H+, m/z 141.055). With 5,000 m/Δm mass resolution at nominal m/z 141, five mass peaks are detected (represented by the grey line).
Image Credit: IONICON Analytik
At approximately m/z 141.05, a dip appears to be present rather than a peak. By observing the PTR-TOF 10k data (represented by the blue line) obtained from the same sample, the situation becomes clear. Ethyl maltol is evidently present (orange area) and completely separable from other isobars within the chocolate headspace.
However, the intensity of ethyl maltol is about an order of magnitude less than those of the most abundant isobar, and as a result, with 5,000 m/Δm, ethyl maltol is practically undetectable.
Similar findings have been revealed for many other m/z, for example, nominal m/z 153, which is shared by the isobaric aroma compounds vanillin, carveol, and ethyl guaiacol. Only the PTR-TOF 10k was able to clearly isolate the individual peaks present in the mass spectrum.
In addition, a fourth isobar was discovered that was “hidden” in the rightmost slope of the carveol peak for the 5,000 m/Δm resolution device.
In the case of nosespace analysis, both during and following food consumption, the case becomes more complicated. This is not only due to the food components but also due to potentially isobaric room air and endogenous compounds from human metabolism appearing in the mass spectrum.
In a non-targeted assessment of PTR-TOF 10k nosespace data during the consumption of chocolate at nominal m/z 123, three isobars may be clearly attributed to contamination in the sampling setup, a room air compound, and a compound derived from chocolate (cautiously labeled as trimethylpyrazine), respectively.
In conclusion, the study demonstrates that the extreme mass resolution of the PTR-TOF 10k provides invaluable advantages for food research. Within this field, more resolution is certainly better.
This information has been sourced, reviewed and adapted from materials provided by IONICON Analytik.
For more information on this source, please visit IONICON Analytik.