Fingerprint Analyses Using MALDI Imaging and SEM Imaging
MALDI imaging is a state-of-art mass spectrometry technique that allows for the visualization of chemical distributions on the surfaces of biological and material samples. This analytical technique can provide the chemical distribution on the surface as an image that is mapped using the intensity of the observed ions. The image contains individual MALDI mass spectra at each pixel. Therefore, it is possible to simultaneously carry out high-mass-resolution qualitative analysis and chemical distribution analysis. The JMS-S3000 SpiralTOF (Figure 1) has a unique 17m fl ight path that offers the highest mass resolution and mass accuracy MALDI-TOF MS system. In this work, we demonstrated the MALDI imaging measurement for the fi ngerprints of a smoker and a non-smoker by using the JEOL SpiralTOF system. Additionally, we looked at the smoker’s fi ngerprint using the JEOL JSM-7800F thermal fi eld emission scanning electron microscope (FE-SEM) shown in Figure 2.
Sample information and preparation conditions are described below.
- A non-smoker’s fi ngerprint
• A smoker’s fi ngerprint
MALDI Imaging measurement
- Measurement mode: SpiralTOF positive mode
- Matrix: 2,5-Dihydroxybenzoic Acid (DHB), 2mL spray @ 30mg/mL
- Measurement region: Width 7.0 mm x Length 10.0 mm
- Analytics Software: Biomap 3.8 - Raw data was converted to imzML fi les
SEM Imaging measurement
- Sample preparation: Uncoated
- Acceleration voltage: 1 kV
- Magnifi cation: 50x and 5,000x