Sandpaper: Efficient Medium for Analysis of Polishable Solid Samples by Ambient Mass Spectrometry

In this paper, we employed sandpaper as an efficientmedium toanalyze polishable solid samples. As proof of principle, the surfacesof coffee beans were sanded with pieces of sandpaper cut into a triangularshape. The triangle was placed in front of the mass spectrometer inlet,and methanol was dropped on its surface. After a high-voltage application,the fingerprints of the coffee beans (n = 100) wereachieved in the positive and negative ion modes in an identical procedureemployed for paper spray mass spectrometry (PS-MS) analysis. The newmethodology, named sandpaper spray mass spectrometry (SPS-MS), allowedfor identifying many compounds in coffee beans, mainly caffeine,sugars, and carboxylic acids, among other molecules. The new techniqueshows advantages over PS-MS in analyzing polishable solid samples.Furthermore, compared to the direct analysis of tissues such as leaves,grains, and seeds, in which the pieces must be cut in a triangularshape (a difficult task depending on the samples & PRIME; hardness),the SPS-MS technique is much more straightforward. Finally, SPS-MScan be potentially applied to analyze other hard surfaces such aswood, plastic, and assorted crop grains.

Automated summary

In this paper, the researchers used sandpaper as a tool to analyze polishable solid samples. They demonstrated the feasibility of this method by sanding the surface of coffee beans and obtaining fingerprints using mass spectrometry. The new technique, named sandpaper spray mass spectrometry (SPS-MS), has advantages over traditional paper spray mass spectrometry in analyzing polishable solid samples and offers a more straightforward approach for analyzing hard surfaces such as wood, plastic, and crop grains.