Related Articles

• Mass Spectrometry Imaging (MSI) on mixed conductive/non-conductive substrate using JMS-S3000 SpiralTOF™ - MSTips - 288

  In the industrial field, there is interest in measuring organic compounds on non-conductive substrates, such as resins a few millimeters thick. If the mass spectrum is obtained from the non-conductive surface with no pre-treatment, the mass resolution will be lower, and ultimately the ion intensity will decrease significantly due to the charge-up effect. This issue can be solved by providing conductivity to the non-conductive part via the gold deposition method.[1] In this report, MSI is performed using a permanent red marker on a substrate with a conductive part and a non-conductive part. Previously, ions could be observed only from the conductive part. Now, with the gold deposition method, they can be observed from both the conductive and the non-conductive parts, and they can be properly mapped.
• High Mass Resolution MALDI-imaging MS Using JMS-S3000 SpiralTOF and msMicroImager

  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.
• Non-targeted analysis of electronics waste by comprehensive two-dimensional gas chromatography combined with high-resolution mass spectrometry: Using accurate mass information and mass defect analysis to explore the data

  Comprehensive two-dimensional gas chromatography (GC×GC) and high-resolution mass spectrometry (HRMS) offer the best possible separation of their respective techniques. Recent commercialization of combined GC×GC–HRMS systems offers new possibilities for the analysis of complex mixtures. However, such experiments yield enormous data sets that require new informatics tools to facilitate the interpretation of the rich information content. This study reports on the analysis of dust obtained from an electronics recycling facility by using GC×GC in combination with a new high-resolution time-of-flight (TOF) mass spectrometer. New software tools for (non-traditional) Kendrick mass defect analysis were developed in this research and greatly aided in the identification of compounds containing chlorine and bromine, elements that feature in most persistent organic pollutants (POPs). In essence, the mass defect plot serves as a visual aid from which halogenated compounds are recognizable on the basis of their mass defect and isotope patterns. Mass chromatograms were generated based on specific ions identified in the plots as well as region of the plot predominantly occupied by halogenated contaminants. Tentative identification was aided by database searches, complementary electron-capture negative ionization experiments and elemental composition determinations from the exact mass data. These included known and emerging flame retardants, such as polybrominated diphenyl ethers (PBDEs), hexabromobenzene, tetrabromo bisphenol A and tris (1-chloro-2-propyl) phosphate (TCPP), as well as other legacy contaminants such as polychlorinated biphenyls (PCBs) and polychlorinated terphenyls (PCTs).
• Analysis of Electronics Waste by GCxGC Combined with High-resolution Mass Spectrometry: Using Accurate Mass Information and Mass Defect Analysis to Explore the Data

  Comprehensive two-dimensional gas chromatography (GCxGC) in combination with high-resolution mass spectrometry (HRMS) is a powerful tool for the analysis of complex mixtures. However, new software tools are required to facilitate the interpretation of the rich information content in GCxGC/HRMS data sets. In this work, we analyzed a dust sample collected from an electronics recycling facility by using GCxGC in combination with a new high-resolution time-of-flight (TOF) mass spectrometer. Nontraditional Kendrick Mass Defect (KMD) plots were used to identify halogenated contaminants in an electronics waste sample. Database search results combined with elemental composition determinations from exact-mass data were used to identify (potential) persistent organic pollutants (POPs).
• High Mass Resolution MALDI-MS Imaging Part II: Using the "MALDIVision" from PREMIER Biosoft

  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.
• High Mass Resolution MALDI-Imaging MS: High Stability of Peak Position during Imaging MS Measurement

  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.