Rapid Analysis of α-Tocopherol and Its Oxidation Products Using Supercritical Carbon Dioxide and Proton Transfer Reaction Ionization Mass Spectrometry

Chihiro Ota; Toshinobu Hondo; Yumi Miyake; Hiroshi Furutani; Michisato Toyoda

doi:10.5702/massspectrometry.A0108

Rapid Analysis of α-Tocopherol and Its Oxidation Products Using Supercritical Carbon Dioxide and Proton Transfer Reaction Ionization Mass Spectrometry

Mass Spectrom (Tokyo). 2022;11(1):A0108. doi: 10.5702/massspectrometry.A0108. Epub 2022 Dec 20.

Authors

Chihiro Ota^{1

2}, Toshinobu Hondo^{2

3}, Yumi Miyake², Hiroshi Furutani^{2

4}, Michisato Toyoda²

Affiliations

¹ Graduate School of Science and Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan.
² Forefront Research Center, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
³ MS-Cheminformatics LLC, Sasao-nishi 2-13-21, Toin, Inabe, Mie 511-0231, Japan.
⁴ Center for Scientific Instrument Renovation and Manufacturing Support, Osaka University, 1-2 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.

Abstract

We have developed a rapid and sensitive analytical method for α-tocopherol and its oxidative products by combining online hyphenation of supercritical fluid extraction-supercritical fluid chromatography (SFC) with proton transfer reaction (PTR) ionization mass spectrometry (MS). α-Tocopherol is a well-known antioxidant that plays a vital role in the antioxidant defense system in plant cells. However, studies on the cellular mechanisms of α-tocopherol have been limited owing to the lack of a rapid analytical method, which limits the comparison of plant cells incubated in various conditions. Additionally, complex sample preparation and long chromatography separation times are required. Moreover, the majority of the involved molecules are a combination of isomers, which must be separated before applying tandem MS. α-Tocopherol produces the α-tocopheroxyl radical in the first step of its antioxidant function; another ion with the same mass may also be generated from the source. SFC separation effectively distinguished the observed ions from their oxidative products in the sample and those produced during the ionization reaction process. This method enabled the measurement of α-tocopherol and its oxidative products such as α-tocopheroxyl radical and α-tocopheryl quinone in approximately 3 min per sample, including the time required for sample preparation.

Keywords: antioxidant; chemical ionization; proton-transfer reaction; supercritical fluid extraction-supercritical fluid chromatography; α-tocopherol.