This experiment was conducted to demonstrate the strength of the photo-desorption analyzer: the analysis of organic compounds on organic substrates. As an example, we analyzed oil contamination on PET. The figure below shows the photo-desorption data for PET at room temperature.
Since PET is composed of double bonds, there are no eluting components. Neither the target mass nor the pressure in the analysis chamber has changed, confirming the absence of eluting components.

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Figure 1: PET photodissociation data

The figure below shows an example of intentionally contaminating PET and analyzing the contamination. Focusing on m/z 29, the charts for pure PET and contaminated PET are compared.
As can be seen here, this enables the analysis of organic compounds on organic substrates—a type of analysis that was previously impossible.


Figure 2: Comparison Data with Contaminated PET