Application of Tandem Mass Spectra for the Peaks of Isotope Pattern in the Elemental Composition Assignment of Product Ions

Abstract

For an ion of known formula, there are some ambiguous formulas with respect to its product ions in tandem mass spectrometry in many cases. Researchers determined them mainly by high resolution mass spectrometer combing database searching. Here, we presented an innovative method to enhance the assignment possibility of the elemental composition of the product ion by exploiting the tandem mass spectra of isotopic peaks from the precursor ion such as＋ . This approach involved a process of excluding low match formulas for product ion stepwise until the final formula with the highest match. It also facilitated the deduction of the fragmentation pathway for the precursor ion in tandem mass spectrometry. The isotopic proportions of product ions possessed a good repeatability. Additionally, this method could be performed fast and conveniently on variety of instruments, which offers an alternative determination tool for the elemental composition of product ion in tandem mass spectrometry.

Analysis of Volatile Compounds in Radix Bupleuri Injection by GC–MS–MS

“…. As a result, the product ion isotope pattern analysis reported by Leng et al [23] was used for elucidation of the elemental composition of the precursor ion.…”

Analysis of the Volatile Compounds in Senecio Scandens Buch-Ham by Gas Chromatography—Tandem Mass Spectrometry Based on Diversified Scan Technologies

“…thus, the tandem mass spectra of m/z 150 and its isotopic pattern m/z 151 were selected for the experiment and were used to determinate the elemental composition of the product ion at m/z 107 ( figure 4). the experimental and theoretical abundance ratio of I 107 :I 108 were concluded according to the article reported by Leng et al 11 the experimental abundance ratio, I 107 /I 108 , was 0.41, and the theoretical abundance ratio, I 107 :I 108 , was c 9 H 10 o 2 and c 10 H 14 o were 0.50 and 0.43, respectively. the data are shown in table 2. from the results, the elemental composition of the product ion could be assigned to c 7 H 7 o + and chromatographic peak 41 could be identified as the compound verbenone due to the higher match of the theoretical value with 0.43. thus, this scan method would provide the elemental composition information and narrow the scope of the mass database research for the following scan methods in qualitative analysis.…”

“…Some compounds could produce particular neutral loss fragment with a retro-Diels-Alder (rDA) reaction in the EI source. 11,22,23 So, the neutral loss scan would easily distinguish the two compounds when only one of them has a particular neutral loss fragment according to the structure and the fragmentation mechanism of mass spectrometry of the compounds. two isomers, e, 4-terpineol, and f, b-terpineol, were considered as the candidate compounds for chromatographic peak 39 (figure 9).…”

“…5 tandem mass spectrometry (MS/MS) technology is an important tool to confirm the elemental composition of compounds and distinguish isomers and isobars. [6][7][8][9] the elemental composition of compounds could be confirmed by high-resolution mass spectrometry, 1,10,11 while they could also be confirmed by exploiting the tandem mass spectra of isotopic peaks from the precursor ion. 11 the product ion scan supplied the fragmentation information of the precursor ion, 6,[12][13][14] which can be used for the discrimination of parent ions with the same molecular weight and reducing the false matching rate.…”

Deep learning under mass‐to‐charge ratio pre‐retrieval to realize electron ionization mass spectrometry library retrieval

“…The ion peaks with larger m/z values, including molecular ion peaks, 9 stable quasi-molecular ion peaks, and isotopic ion peaks, provide crucial information. 10 The information in these ion peaks plays an important role in the library search, so these characteristic peaks are selected for performing the match. The five characteristic peaks at maximum m/z values are selected in the reference spectrum and three in the query spectrum.…”