Journal of The American Society for Mass Spectrometry

, Volume 24, Issue 10, pp 1451–1455

Mechanism of Formation of the Major Estradiol Product Ions Following Collisional Activation of the Molecular Anion in a Tandem Quadrupole Mass Spectrometer

Authors

  • Kerry M. Wooding
    • Department of Obstetrics and GynecologyUniversity of Colorado School of Medicine
    • Department of PharmacologyUniversity of Colorado Denver
  • Robert M. Barkley
    • Department of PharmacologyUniversity of Colorado Denver
  • Joseph A. Hankin
    • Department of PharmacologyUniversity of Colorado Denver
  • Christopher A. Johnson
    • Department of PharmacologyUniversity of Colorado Denver
  • Andrew P. Bradford
    • Department of Obstetrics and GynecologyUniversity of Colorado School of Medicine
  • Nanette Santoro
    • Department of Obstetrics and GynecologyUniversity of Colorado School of Medicine
    • Department of PharmacologyUniversity of Colorado Denver
Short Communication

DOI: 10.1007/s13361-013-0705-y

Cite this article as:
Wooding, K.M., Barkley, R.M., Hankin, J.A. et al. J. Am. Soc. Mass Spectrom. (2013) 24: 1451. doi:10.1007/s13361-013-0705-y

Abstract

The importance of the mass spectral product ion structure is highlighted in quantitative assays, which typically use multiple reaction monitoring (MRM), and in the discovery of novel metabolites. Estradiol is an important sex steroid whose quantitation and metabolite identification using tandem mass spectrometry has been widely employed in numerous clinical studies. Negative electrospray ionization tandem mass spectrometry of estradiol (E2) results in several product ions, including the abundant m/z 183 and 169. Although m/z 183 is one of the most abundant product ions used in many quantitative assays, the structure of m/z 183 has not been rigorously examined. We suggest a structure for m/z 183 and a mechanism of formation consistent with collision induced dissociation (CID) of E2 and several stable isotopes ([D4]-E2, [13C6]-E2, and [D1]-E2). An additional product ion from E2, namely m/z 169, has also been examined. MS3 experiments indicated that both m/z 183 and m/z 169 originate from only E2 [M – H]m/z 271. These ions, m/z 183 and m/z 169, were also present in the collision induced decomposition mass spectra of other prominent estrogens, estrone (E1) and estriol (E3), indicating that these two product ions could be used to elucidate the estrogenic origin of novel metabolites. We propose two fragmentation schemes to explain the CID data and suggest a structure of m/z 183 and m/z 169 consistent with several isotopic variants and high resolution mass spectrometric measurements.

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Key words

EstradiolEstroneEstriolTandem mass spectrometryProduct ion structure

Supplementary material

13361_2013_705_MOESM1_ESM.pdf (316 kb)
ESM 1(PDF 316 kb)
13361_2013_705_MOESM2_ESM.pdf (188 kb)
ESM 2(PDF 187 kb)
13361_2013_705_MOESM3_ESM.docx (20 kb)
ESM 3(DOCX 20 kb)

Copyright information

© American Society for Mass Spectrometry 2013