Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (12): 3632.doi: 10.7503/cjcu20210318

• Analytical Chemistry • Previous Articles     Next Articles

Characteristic Analysis of C1—C3n-Aldehydes and n-Alcohols in Proton Transfer Reaction Time-of-flight Mass Spectrometry

WANG Ruxin1, ZHAO Zhongjun2, HE Feiyao1, YUE Hanlu1, DENG Fulong1, LI Hong1, LI Wenwen3(), DUAN Yixiang1()   

  1. 1.College of Life Science
    2.College of Chemical Engineering
    3.West China of Public Health and West China Forth Hospital,Sichuan University,Chengdu 610064,China
  • Received:2021-05-08 Online:2021-12-10 Published:2021-08-11
  • Contact: DUAN Yixiang E-mail:wenwentp@163.com;yduan@scu.edu.cn
  • Supported by:
    the Special Project of Major Scientific Instruments and Equipment in Sichuan Province, China(2019ZDZX0036)

Abstract:

Proton transfer reaction time-of-flight mass spectrometer(PTR-TOF-MS) is a kind of soft chemical ionization mass spectrometry instrument, which can realize real-time online detection of trace volatile organic compounds. The E/N value(E: electric field intensity, N: gas molecule number density) is an important parameter in the proton transfer reaction, which will affect the type and content of product ions. Herein, the effects of different E/N values on the types and relative strengths of C1—C3n-aldehydes and n-alcohol product ions were systematically investigated, and the proton transfer reaction characteristics of C1—C3 n-aldehydes and n-alcohols as well as the formation pathways of fragment ions were studied. The results show that low molecular weight n-alcohols(methanol, ethanol and propanol) tend to form protonated polymers [nMH]+ and their dehydrated ions [nMH-H2O]+, and as the E/N value increases, n-alcohols will produce more fragments and polymer ions. Low molecular weight n-aldehydes(formaldehyde, acetaldehyde and propanal) mainly produce protonated products [MH]+ and monohydrate protonated products [M·H3O]+. High E/N value(>125 Td) will inhibit the protonation of formaldehyde and the formation of its adducts. Acetaldehyde is more inclined to form water adducts, and the change trend of [CH3CHOH]+ and [CH3CHOH·H2O]+ is opposite with the increase of E/N value. In addition, propanal will produce a series of polymers([C2H5CHOH·C2H5+, [C2H5CHOH·C2H5CHO]+) at higher E/N values. In this paper, the best analytical E/N values and characteristic fragment ions of C1—C3n-aldehydes and n-alcohols were obtained, which is expected to provide an important basis for the qualitative and quantitative analysis of low molecular weight aldehydes and alcohols.

Key words: Proton transfer reaction mass spectrometer, C1—C3n-aldehydes and n-alcohols, Time-of-flight mass spectrometry

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