Analyzing a Specific Component using Group Analysis of msFineAnalysis Ver. 2 - MSTips 303 April 13, 2020 AccuTOF™ GC, Application Note, Mass Spectrometry (MS), Materials, msFineAnalysis msFineAnalysis 0 Integrated Analysis Results of a Vinyl Acetate Resin Product: JMS-T200GC GC /MS System Introduction Electron ionization (EI) is a hard ionization method that is commonly used with gas chromatography mass spectrometry (GC-MS). The mass spectral fragmentation patterns produced by EI are used for library database searches to identify compounds. Conversely, soft ionization methods like field ionization (FI) tend to produce clear molecular ions with minimal fragmentation. When high-resolution MS is used with these ionization techniques, the accurate masses for the fragment ions produced by EI and the molecular ions produced by soft ionization provide an additional dimension of information for the analytes. Combining the exact mass information with the results of conventional library search can enhance the accuracy of identification compared to the use of library search alone. 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. Software Enhancements Chromatographic Deconvolution: The msFineAnalysis Version 2 software supports chromatographic deconvolution to reconstruct mass spectra by using the information (m/z, area) from extracted ion chromatograms (EIC) created using exact mass information. Chromatographic deconvolution is effective in separating coeluting components which are detected as a single peak in the total ion current chromatogram (TICC). Group Analysis: Group analysis can be used after chromatographic deconvolution to identify compounds that have common substructures. Group analysis is accomplished by creating mass chromatograms from the exact mass data to identity compounds that have the same molecular weight, or that have common fragments or neutral losses. Figure 1 shows the graphical user interface (GUI) for Group analysis. Experiment A commercial vinyl acetate resin was used as a model sample. A JEOL JMS-T200GC GC-HRTOFMS was used for analysis, and a Frontier Lab pyrolysis inlet was used for sample pretreatment. Additionally, the system was equipped with an EI/FI combination ion source for this work. The resulting data were analyzed by using msFineAnalysis version 2 (JEOL). Table 1 shows the pyrolysis and GC-HRTOFMS analysis conditions. Table 1. Measurement conditions [Pyrolysis Conditions] Pyrolyzer PY-3030D (Frontier Lab) Pyrolysis Temperature 600°C [GC-TOFMS Conditions] System JMS-T200GC (JEOL) Ion Source EI/FI combination ion source Ionization mode EI+: 70 eV, 300 μA FI+: -10 kV, 6mA/10msec (Carbotec) GC column DB-5MSUI, 30 m x 0.25 mm, 0.25 μm Oven temp. 50°C (1 min) → 30°C/min → 330°C (1.7 min) Inlet mode Split 100:1 Figure 1. Group Analysis Window Figure 2. Group analysis results of C6H5 ion Results and discussions Figure 1 shows the C6H5 fragment ions that were detected in the pyrolysis GC-MS results for the vinyl acetate resin. This fragment ion is characteristic for aromatic compounds. The table on the right shows that there are 26 compounds containing C6H5. The view on the left allows the operator to quickly identify where the components containing this ion were detected. The view on the left top shows the GC/EI data with the TICC marked by a solid black line. The bottom left view shows the soft ionization data with the TICC marked by a solid green line. The blue peaks in both views represent the components containing C6H5 extracted from the chromatographic deconvolution result. The operator can select an ion such as C6H5 from the table and click the OK button at the bottom right of the GUI to immediately create a C6H5 tab, thus allowing for extraction of the components containing that specific fragment (Figure 2). Figure 2 shows the extracted results for components containing C6H5. The Group Analysis function displays an “All” tab for the entire analysis results and up to 5 tabs for groups created for ions or neutral losses specified from the exact mass list in Figure 1. For example, the operator can select a fragment ion containing nitrogen, phosphate, or sulfur to find a group of compounds containing the specified elements. The ID and integrated analysis results are then shared between tabs. The results under the C6H5 tab represent a group of aromatic compounds. Conclusions The msFineAnalysis program is designed to run integrated analysis with or without library search. It is a qualitative program based on a new concept that is effective for non-targeted analysis. The basic functions of the program are capable of identifying numerous components for non-targeted analysis. Group Analysis adds the capability to extract specific compounds or families of related compounds in the same manner as target analysis, speeding up the process of their detailed analysis. For full details: Attached files often contain the full content of the item you are viewing. Be sure and view any attachments. Analyzing a Specific Component using Group Analysis of msFineAnalysis Ver. 2 - MSTips 303.pdf 346.29 KB Related Articles 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 2: Reproducibility of group-type analysis results 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. 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In this work, we will introduce a new technique of non-targeted analysis, which combines comprehensive analysis using high resolution GC-MS and unknown component analysis using soft ionization and EI. Comprehensive Analysis + Unknown Component Analysis of Vinyl Acetate Resins Using Pyrolysis GC-MS Advances in mass spectrometry are enabling analysis of micro samples and unknown components that were not observable before. As the volume of information acquired from mass spectrometry increases, researchers are calling for simple techniques to analyze numerous components observed, and as a result, there is a rise in demand for comprehensive analytical techniques including multiple classification analysis. In this work, we will introduce a new technique for non-target analysis, which combines comprehensive analysis using high resolution GC-TOFMS and unknown component analysis using soft ionization. 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. Showing 0 Comment Comments are closed.