Skip to main content

Ozone-induced dissociation on a modified tandem linear ion-trap: observations of different reactivity for isomeric lipids

Journal Article


Abstract


  • Ozone-induced dissociation (OzID) exploits the gas-phase reaction between mass-selected lipid ions and ozone vapor to determine the position(s) of unsaturation. In this contribution, we describe the modification of a tandem linear ion-trap mass spectrometer specifically for OzID analyses wherein ozone vapor is supplied to the collision cell. This instrumental configuration provides spatial separation between mass-selection, the ozonolysis reaction, and mass-analysis steps in the OzID process and thus delivers significant enhancements in speed and sensitivity (ca. 30-fold). These improvements allow spectra revealing the double-bond position(s) within unsaturated lipids to be acquired within 1 s: significantly enhancing the utility of OzID in high-throughput lipidomic protocols. The stable ozone concentration afforded by this modified instrument also allows direct comparison of relative reactivity of

    isomeric lipids and reveals reactivity trends related to (1) double-bond position, (2) substitution position on the glycerol backbone, and (3) stereochemistry. For cis- and trans-isomers, differences were also observed in the branching ratio of product ions arising from the gas-phase ozonolysis reaction, suggesting that relative ion abundances could be exploited as markers for double-bond geometry. Additional activation energy applied to mass-selected lipid ions during injection into the collision cell (with ozone present) was found to yield spectra containing both OzID and classical-CID fragment ions. This combination CID-OzID acquisition on an ostensibly simple monounsaturated phosphatidylcholine within a cow brain lipid extract provided evidence for up to four structurally distinct phospholipids differing in both double-bond position and sn-substitution.

UOW Authors


  •   Poad, Berwyck L. J.
  •   Pham, Huong T. (external author)
  •   Thomas, Michael C. (external author)
  •   Nealon, Jessica
  •   Campbell, J Larry. (external author)
  •   Mitchell, Todd
  •   Blanksby, Stephen J. (external author)

Publication Date


  • 2010

Citation


  • Poad, B. L., Pham, H. Thu., Thomas, M., Hughes, J. R., Campbell, J. Larry., Mitchell, T. W. & Blanksby, S. J. (2010). Ozone-induced dissociation on a modified tandem linear ion-trap: observations of different reactivity for isomeric lipids. Journal of the American Society for Mass Spectrometry, 21 (12), 1989-1999.

Scopus Eid


  • 2-s2.0-78649529343

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4601

Number Of Pages


  • 10

Start Page


  • 1989

End Page


  • 1999

Volume


  • 21

Issue


  • 12

Place Of Publication


  • http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TH2-50V5NK8-1-X&_cdi=5270&_user=202616&_pii=S1044030510005623&_origin=browse&_coverDate=12%2F31%2F2010&_sk=999789987&view=c&wchp=dGLbVtb-zSkWb&md5=b51114789cd4f1c1243aa3019b525118&ie=/sdarticle.pdf

Abstract


  • Ozone-induced dissociation (OzID) exploits the gas-phase reaction between mass-selected lipid ions and ozone vapor to determine the position(s) of unsaturation. In this contribution, we describe the modification of a tandem linear ion-trap mass spectrometer specifically for OzID analyses wherein ozone vapor is supplied to the collision cell. This instrumental configuration provides spatial separation between mass-selection, the ozonolysis reaction, and mass-analysis steps in the OzID process and thus delivers significant enhancements in speed and sensitivity (ca. 30-fold). These improvements allow spectra revealing the double-bond position(s) within unsaturated lipids to be acquired within 1 s: significantly enhancing the utility of OzID in high-throughput lipidomic protocols. The stable ozone concentration afforded by this modified instrument also allows direct comparison of relative reactivity of

    isomeric lipids and reveals reactivity trends related to (1) double-bond position, (2) substitution position on the glycerol backbone, and (3) stereochemistry. For cis- and trans-isomers, differences were also observed in the branching ratio of product ions arising from the gas-phase ozonolysis reaction, suggesting that relative ion abundances could be exploited as markers for double-bond geometry. Additional activation energy applied to mass-selected lipid ions during injection into the collision cell (with ozone present) was found to yield spectra containing both OzID and classical-CID fragment ions. This combination CID-OzID acquisition on an ostensibly simple monounsaturated phosphatidylcholine within a cow brain lipid extract provided evidence for up to four structurally distinct phospholipids differing in both double-bond position and sn-substitution.

UOW Authors


  •   Poad, Berwyck L. J.
  •   Pham, Huong T. (external author)
  •   Thomas, Michael C. (external author)
  •   Nealon, Jessica
  •   Campbell, J Larry. (external author)
  •   Mitchell, Todd
  •   Blanksby, Stephen J. (external author)

Publication Date


  • 2010

Citation


  • Poad, B. L., Pham, H. Thu., Thomas, M., Hughes, J. R., Campbell, J. Larry., Mitchell, T. W. & Blanksby, S. J. (2010). Ozone-induced dissociation on a modified tandem linear ion-trap: observations of different reactivity for isomeric lipids. Journal of the American Society for Mass Spectrometry, 21 (12), 1989-1999.

Scopus Eid


  • 2-s2.0-78649529343

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4601

Number Of Pages


  • 10

Start Page


  • 1989

End Page


  • 1999

Volume


  • 21

Issue


  • 12

Place Of Publication


  • http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TH2-50V5NK8-1-X&_cdi=5270&_user=202616&_pii=S1044030510005623&_origin=browse&_coverDate=12%2F31%2F2010&_sk=999789987&view=c&wchp=dGLbVtb-zSkWb&md5=b51114789cd4f1c1243aa3019b525118&ie=/sdarticle.pdf