Versatility of tandem mass spectrometry for focused analysis of oxylipids.
Liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the multiple reaction monitoring (MRM) scan mode has been the primary MS method applied for the target identification of specific and minor oxylipids in complex matrices, such as eicosanoids and docosanoids, which are potent lipid mediators derived from polyunsaturated fatty acid oxygenation. However, the high specificity of MRM can limit the detection of species with m/z MRM transitions not covered by the method. In addition to MRM, tandem-quadrupole mass analyzers enable other experiments to be conducted, by fragmenting ions via collision-induced dissociation process (CID). This paper presents the potential of tandem mass spectrometry for the focused analysis of oxylipids. We have successfully developed an LC-MS/MS method for the identification of precursor ions of m/z 115, a diagnostic product ion of 5-hydroxy- and 5-epoxy-fatty acids. As a proof of concept, the developed method was used to discover several oxylipids oxidized at C5 derived from arachidonic acid (C20 : 4) oxygenation in a hypothalamus rat extract that were not identified using the target MRM methodology. The proposed focused MS/MS-based approach in a tandem mass analyzer has proven to be a powerful strategy to accelerate the identification of oxylipids with structural similarities and assist the field of lipidomic research.
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Avenida do Café s/n, Ribeirão Preto, SP, CEP 14040-903, Brazil.
Tania
T
Petta
Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Bairro Monte Alegre, Ribeirão Preto, SP, CEP 14040-901, Brazil.
Luiz A B
LA
Moraes
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Avenida do Café s/n, Ribeirão Preto, SP, CEP 14040-903, Brazil.
Lúcia H
LH
Faccioli
D000818:Animals; D000838:Anions; D002853:Chromatography, Liquid / Q000379:methods*; D008055:Lipids / Q000032:analysis* / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D053719:Tandem Mass Spectrometry / Q000379:methods*
D000838:Anions; D008055:Lipids
eicosanoids; focused lipidomics; liquid chromatography-tandem mass spectrometry; multiple reaction monitoring; oxylipids; precursor ion scan