Related Articles

• “Fraction base” KMD plots for a high molecular weight poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolyester following its on-plate alkaline degradation and SpiralTOFTM analysis

  High molecular weight polymers are often MS-silent due to their inherent high dispersity (ĐM) or detected in the high mass range with low resolving power. An “on-plate” alkaline degradation has thus been developed as a sample pre-treatment on the MALDI target with tenths of ng of polymer to cut long industrial polyester chains into short oligomers amenable to MALDI-HRMS [1]. The complicated mass spectrum of P3HB oligomers was analyzed by fraction base Kendrick mass defect (KMD) plot [2]. Fraction base KMD analysis has been developed from the regular KMD analysis to modify the aspect and separation capabilities of the KMD plots depending on a divisor (noted X) in addition to the base unit (noted R) via a fraction base R/X [3].
• “Fraction base” KMD plots for a high molecular weight poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolyester following its on-plate alkaline degradation and SpiralTOFTM analysis

  High molecular weight polymers are often MS-silent due to their inherent high dispersity (ĐM) or detected in the high mass range with low resolving power. High-resolution mass spectrometry (HRMS) is indeed limited to the low mass range (< 3000 Da) for an unambiguous evaluation of the nature of repeating units and/or end-groups or the isolation of isobaric compounds. An “on-plate” alkaline degradation has thus been developed as a sample pre-treatment on the MALDI target with tenths of ng of polymer to cut long industrial polyester chains into short oligomers amenable to MALDI-HRMS [1]. The complexity of the associated mass spectra can be greatly reduced with the appropriate resolution-enhanced Kendrick mass defect (KMD) analysis using the “fraction base” option of msRepeatFinder to produce compositional maps.
• Integrated Analysis of an Acrylic Resin using msFineAnalysis v2 - MSTips 300

  In 2018, msFineAnalysis Ver.1 software was released in which data acquired by EI, soft ionization, and accurate mass measurements were automatically integrated to generate a qualitative report for samples measured by these techniques with GC-MS. Recently, msFineAnalysis Ver.2 was introduced as an enhanced version with additional features. In this work, we will describe the changes in Ver.2, which now includes chromatographic deconvolution, and present applications using the new features.
• Group-type Analysis of Crude Oil by Using GC/FI-TOFMS Part 1: Determination of average molecular weights

  Field Desorption (FD) and Field Ionization (FI) are both techniques that ionize analytes by electron tunneling from the analyte molecules to a solid surface (emitter) in a high electric field. In the case of FD, the sample is applied directly onto the emitter and heated by applying an electric current through the emitter for desorption and ionization. In the case of FI, vaporized analyte molecules are introduced into the proximity of the emitter. Both FI and FD are soft ionization methods that generally yield intact molecular ions and, in most cases, produce very few fragment ions. Generally, these two techniques are used to ionize analytes that are easy to fragment and do not generally produce molecular ions during electron ionization (EI), such as hydrocarbons in crude oil.
• Analyzing a Specific Component using Group Analysis of msFineAnalysis Ver. 2 - MSTips 303

  In 2018, we announced the msFineAnalysis software which was designed to automatically integrate two types of data acquired by EI and soft ionization. Recently, we developed msFineAnalysis Version 2, an enhanced version with additional features. msFineAnalysis Version 2 incorporates two new features: Chromatographic Deconvolution and Group Analysis. In this work, we use the group analysis capabilities of the software to evaluate the pyrolysis GC-MS results for a vinyl acetate resin.
• 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).