Skip to main content
placeholder image

Combining Charge-Switch Derivatization with Ozone-Induced Dissociation for Fatty Acid Analysis

Journal Article


Abstract


  • The specific positions of carbon-carbon double bond(s) within an unsaturated fatty acid exert a significant effect on the physical and chemical properties of the lipid that ultimately inform its biological function(s). Contemporary liquid chromatography-mass spectrometry (MS) strategies based on electrospray ionization coupled to tandem MS can easily detect fatty acyl lipids but generally cannot reveal those specific site(s) of unsaturation. Herein, we describe a novel and versatile workflow whereby fatty acids are first converted to fixed charge N-(4-aminomethylphenyl)pyridinium (AMPP) derivatives and subsequently subjected to ozone-induced dissociation (OzID) on a modified triple quadrupole mass spectrometer. The AMPP modification enhances the detection of fatty acids introduced by direct infusion. Fragmentation of the derivatized fatty acids also provides diagnostic fragment ions upon collision-induced dissociation that can be targeted in precursor ion scans to subsequently trigger OzID analyses in an automated data-dependent workflow. It is these OzID analyses that provide unambiguous assignment of carbon-carbon double bond locations in the AMPP-derivatized fatty acids. The performance of this analysis pipeline is assessed in profiling the patterns of unsaturation in fatty acids within the complex biological secretion vernix caseosa. This analysis uncovers significant isomeric diversity within the fatty acid pool of this sample, including a number of hitherto unreported double bond positional isomers that hint at the activity of potentially new metabolic pathways.

UOW Authors


  •   Poad, Berwyck L. J. (external author)
  •   Marshall, David L. (external author)
  •   Harazim, Eva (external author)
  •   Gupta, Rajesh (external author)
  •   Narreddula, Venkateswara (external author)
  •   Young, Reuben (external author)
  •   Duchoslav, Eva (external author)
  •   Campbell, J Larry. (external author)
  •   Broadbent, James (external author)
  •   Cvacka, Josef (external author)
  •   Mitchell, Todd
  •   Blanksby, Stephen J. (external author)

Publication Date


  • 2019

Citation


  • Poad, B. L. J., Marshall, D. L., Harazim, E., Gupta, R., Narreddula, V. R., Young, R. S. E., Duchoslav, E., Campbell, J. L., Broadbent, J. A., Cvacka, J., Mitchell, T. W. & Blanksby, S. J. (2019). Combining Charge-Switch Derivatization with Ozone-Induced Dissociation for Fatty Acid Analysis. Journal of the American Society for Mass Spectrometry, 30 (10), 2135-2143.

Scopus Eid


  • 2-s2.0-85069749373

Number Of Pages


  • 8

Start Page


  • 2135

End Page


  • 2143

Volume


  • 30

Issue


  • 10

Place Of Publication


  • United States

Abstract


  • The specific positions of carbon-carbon double bond(s) within an unsaturated fatty acid exert a significant effect on the physical and chemical properties of the lipid that ultimately inform its biological function(s). Contemporary liquid chromatography-mass spectrometry (MS) strategies based on electrospray ionization coupled to tandem MS can easily detect fatty acyl lipids but generally cannot reveal those specific site(s) of unsaturation. Herein, we describe a novel and versatile workflow whereby fatty acids are first converted to fixed charge N-(4-aminomethylphenyl)pyridinium (AMPP) derivatives and subsequently subjected to ozone-induced dissociation (OzID) on a modified triple quadrupole mass spectrometer. The AMPP modification enhances the detection of fatty acids introduced by direct infusion. Fragmentation of the derivatized fatty acids also provides diagnostic fragment ions upon collision-induced dissociation that can be targeted in precursor ion scans to subsequently trigger OzID analyses in an automated data-dependent workflow. It is these OzID analyses that provide unambiguous assignment of carbon-carbon double bond locations in the AMPP-derivatized fatty acids. The performance of this analysis pipeline is assessed in profiling the patterns of unsaturation in fatty acids within the complex biological secretion vernix caseosa. This analysis uncovers significant isomeric diversity within the fatty acid pool of this sample, including a number of hitherto unreported double bond positional isomers that hint at the activity of potentially new metabolic pathways.

UOW Authors


  •   Poad, Berwyck L. J. (external author)
  •   Marshall, David L. (external author)
  •   Harazim, Eva (external author)
  •   Gupta, Rajesh (external author)
  •   Narreddula, Venkateswara (external author)
  •   Young, Reuben (external author)
  •   Duchoslav, Eva (external author)
  •   Campbell, J Larry. (external author)
  •   Broadbent, James (external author)
  •   Cvacka, Josef (external author)
  •   Mitchell, Todd
  •   Blanksby, Stephen J. (external author)

Publication Date


  • 2019

Citation


  • Poad, B. L. J., Marshall, D. L., Harazim, E., Gupta, R., Narreddula, V. R., Young, R. S. E., Duchoslav, E., Campbell, J. L., Broadbent, J. A., Cvacka, J., Mitchell, T. W. & Blanksby, S. J. (2019). Combining Charge-Switch Derivatization with Ozone-Induced Dissociation for Fatty Acid Analysis. Journal of the American Society for Mass Spectrometry, 30 (10), 2135-2143.

Scopus Eid


  • 2-s2.0-85069749373

Number Of Pages


  • 8

Start Page


  • 2135

End Page


  • 2143

Volume


  • 30

Issue


  • 10

Place Of Publication


  • United States