Analytical Instrument Documents

In this paper, we report the use of mass spectrometry imaging and structural analysis of lipids directly on a tissue specimen, carried out by means of matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry, using a combination of spiral orbit-type and reflectron-type time-of-flight mass spectrometers. The most intense peak observed in the mass spectrum from a brain tissue specimen was confirmed as phosphatidylcholine (34 : 1) [M+K]+, using tandem mass spectrometry. The charge remote fragmentation channels, which are characteristically observed using high-energy collision induced dissociation, contributed significantly to this confirmation. Accurate mass analysis was further facilitated by mass correction using the confirmed peak. In mass spectrometry imaging, the high resolving power of our system could separate doublet peak of less than 0.1 u diveerence, which would otherwise be problematic when using a low-resolution reflectron type time-of-flight mass spectrometer. Two compounds, observed at m/z 848.56 and 848.65, were found to be located in complementary positions on a brain tissue specimen. These results demonstrate the importance of a high-performance tandem time-of-flight mass spectrometer for mass spectrometry imaging and analysis of observed compounds, to allow distinction between biological molecules.

SpiralTOF is the world’s highest mass resolution MALDI-TOFMS adopting JEOL’s own ion optical system. Features of SpiralTOF for Imaging mass spectrometry (IMS): Ultra-high mass resolution; Low chemical background noise. (Elimination of PSD ions); High Stability of Peak Position during IMS Measurement

The JMS-S3000 SpiralTOF is a MALDI-TOFMS, which utilizes the JEOL patented spiral ion optics system. It has a 5-10 times longer flight path than the typical reflectron type MALDI-TOFMS. As a result, it can achieve high mass-resolution to separate peaks that have the same nominal mass but have different exact masses (isobaric separation). This feature is particularly effective for MALDI-Imaging for drug metabolism, which typically consist of relatively low molecular weight compounds which are often interfered with by matrix compounds and/or surface contaminants.

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MS Imaging) is a powerful tool for the biochemical analyses of surfaces. Previously, this technique has been used to determine the spatial distribution of hundreds of unknown compounds in thinly sliced tissue sections. The mass spectral images are generated by changing the laser irradiation point at regular intervals across the sample surface and collecting a mass spectrum for each point. Time-of-flight mass spectrometers (TOFMS) are widely used as the mass analyzer for MALDI-MS Imaging because they are well matched for the MALDI ionization process. Ultra-high mass resolution achieving isobaric peak separation is important for lipid profiling using MALDI-Imaging [1, 2]. However, the fine structure of the matrix crystals and small irregularities in the tissue surface flatness can cause peak drift in the collected mass spectra that is caused by slight differences in the starting point of the flight path for the ions at each laser irradiation point. As a result, the typical reflectron type TOFMS systems have a difficult time achieving high mass resolution from spot to spot over a thinly sliced biological surface.

Imaging mass spectrometry using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-Imaging) has been expanded during the last decade in biological applications, to assess the distribution of proteins, peptides, lipids, drugs, and metabolites in a tissue specimen. In MALDI-Imaging measurements, a laser irradiation point was scanned on a sample surface to acquire a mass spectrum at each point. Analyzing the mass spectra with two-dimensional position information, localization of compounds with inherent molecular weights can be visualized or the mass spectra for certain regions of interests (ROIs) can be created. The JMS-S3000 SpiralTOF (Fig. 1) is a MALDI-TOFMS, which utilizes the JEOL patented spiral ion optical system. It has a 5-10 times longer flight path than the typical reflectron type MALDI-TOFMS. As a result, it can achieve high mass-resolution to separate peaks that have the same nominal mass but have different exact masses (isobaric separation). On the other hand, there are some issues for analyzing high mass resolution and high lateral resolution MALDI-Imaging raw data with common imaging software options such as Biomap.

Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-Imaging MS) is a powerful tool for the biochemical analyses of surfaces. Previously, this technique has been used to determine the spatial distribution of hundreds of unknown compounds in thinly sliced tissue sections. The mass spectral images are generated by changing the laser irradiation point at regular intervals across the sample surface and collecting a mass spectrum for each point. Time-of-flight mass spectrometers (TOFMS) are widely used as the mass analyzer for MALDI-Imaging MS because they are well matched for the MALDI ionization process. However, the fine structure of the matrix crystals and small irregularities in the tissue surface flatness can cause peak drift in the collected mass spectra that is caused by slight differences in the starting point of the flight path for the ions at each laser irradiation point. As a result, the typical reflectron type TOFMS systems have a difficult time achieving high mass resolution from spot to spot over a thinly sliced biological surface. Conversely, the JEOL JMS-S3000 “SpiralTOFTM”, which has 5-10 times longer flight path than the reflectron type TOF, is able to reduce the effect of this mass drift to achieve high mass resolution and high mass accuracy. In this work, we report the advantages of using the SpiralTOF for MALDI-Imaging MS analyses of lipids in a mouse brain tissue section.

Recently, matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging techniques have been developed for biological sciences to evaluate and understand the distribution of various chemicals on biological surfaces. In particular, this technique provides useful visual information about the locations of specific chemicals on surfaces. In this work, we explored the use of MALDI-MS imaging for the forensically applicable sample of gunshot residues (GSR). These measurements were done using a spiral-trajectory ion optics time-of-flight mass spectrometer (SpiralTOF-MS) which has a 17m flight path that provides high resolution capabilities, even down into the lower m/z region. Additionally, the m/z axis remains very stable over the long time period required for MALDI-MS imaging.

Since 1949, the JEOL legacy has been one of outstanding innovation in developing instruments used to advance scientific research and technology. JEOL has over 60 years of expertise in the field of electron microscopy, more than 50 years in mass spectrometry. In this applications note, we performed an analysis of a Gold Star Mothers Postage Stamp by using three JEOL instruments. We used the JSM-IT300LV which the latest addition to JEOL‘s popular series of analytical low vacuum SEM, , the JMS-T100LP “AccuTOF- DART” the first commercially available ambient ionization mass spectrometer, and the JMS-S3000 “SpiralTOF” which has highest mass-resolution and mass accuracy of all commercially available MALDI-TOFMS systems. We can therefore correlate analyses from various analytical techniques on the same sample.

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.

Recently, matrix assisted laser desorption/ionization (MALDI) imaging techniques have been developed for biological sciences to evaluate and understand the distribution of various chemicals on biological surfaces. In particular, this technique provides useful visual information about the locations of specific chemicals on surfaces. In this work, we explored the use of laser desorption/ionization (LDI) imaging for forensically applicable samples such as a handwriting sample with a ballpoint ink. These measurements were done using a spiral-trajectory ion optics time-of-flight mass spectrometer (SpiralTOF-MS). This TOF system has a 17m flight path that provides high resolution capabilities even down into the lower m/z region. Additionally, we looked at the SEM/EDS imaging using the JEOL JSM-6510LV scanning electron microscope.