Mass Spectrometry
Online ISSN : 2186-5116
Print ISSN : 2187-137X
ISSN-L : 2186-5116
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Review
  • Yoshinao Wada
    2025 Volume 14 Issue 1 Pages A0169
    Published: February 08, 2025
    Released on J-STAGE: February 08, 2025
    Advance online publication: February 05, 2025
    JOURNAL OPEN ACCESS FULL-TEXT HTML

    Congenital disorders of glycosylation (CDG) constitute a group of rare inherited metabolic disorders resulting from mutations in genes involved in the biosynthesis of glycan chains that are covalently attached to proteins or lipids. To date, nearly 200 genes have been identified as responsible for these disorders, with approximately half implicated in N-glycosylation defects. Diagnosis of CDG is primarily achieved through genetic analysis and the identification of glycan abnormalities, referred to as molecular phenotypes. With the increasing use of whole exome and genome sequencing in the investigation of diseases with unknown etiology, the number of cases suspected of CDG is increasing, highlighting the necessity for glycan analysis. Molecular phenotyping in CDG typically targets glycoproteins, with transferrin and apolipoprotein CIII being key representatives of N- and mucin-type O-glycosylation, respectively. Mass spectrometry (MS) provides rapid analysis and yields moderately detailed information, establishing it as a first-line molecular diagnostic tool that complements genetic analysis. Structural anomalies detected by MS can be classified into distinct patterns, which may indicate specific defects within the glycosylation pathway. In cases of CDG types that lack clear molecular phenotypes, characteristic metabolites can often be identified and quantified by MS, further aiding in the diagnostic process. Molecular diagnosis of CDG using MS can be performed with a standard mass spectrometer and a dried blood spot on filter paper, enabling its application in population-based mass screening.

Original Article
  • Azusa Kubota, Takaya Satoh, Masaaki Ubukata, Ayumi Kubo, Chikako Nakay ...
    2025 Volume 14 Issue 1 Pages A0168
    Published: January 15, 2025
    Released on J-STAGE: January 15, 2025
    Advance online publication: January 08, 2025
    JOURNAL OPEN ACCESS FULL-TEXT HTML

    Polyethylene terephthalate (PET) is widely used across various industries owing to its versatility and favorable properties, including application in beverage bottles, food containers, textile fibers, engineering resins, films, and sheets. However, polymer materials are susceptible to degradation from factors such as light, oxygen, and heat. Therefore, it is crucial to understand the structural changes that occur during degradation and the extent of these changes. This report investigates the structural alterations in PET films resulting from ultraviolet (UV) irradiation utilizing pyrolysis–gas chromatography time-of-flight mass spectrometry (Py-GC-TOFMS) and matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOFMS). Using the reactive Py-GC-TOFMS, we estimated the composition of the pyrolysis products resulting from UV degradation through electron ionization, soft ionization, and exact mass measurements. Additionally, artificial intelligence (AI)-based structure analysis was performed to evaluate these compounds’ structures. Notably, most degradation products were not found in the National Institute of Standards and Technology database, underscoring the effectiveness of our approach. Using MALDI-TOFMS analysis, we determine the changes in the end groups before and after UV irradiation. This analysis confirmed the generation of a series of carboxylic acid end groups as a result of degradation, a polymer series not detected by reactive pyrolysis GC-MS. We also explored degradation in the depth direction, demonstrating that degradation progresses gradually to depths of several micrometers. Our findings highlight the importance of employing mass spectrometry techniques for a comprehensive analysis of polymer degradation.

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