Existing mass spectrometric methods for the analysis of fatty acids often require derivatization, chromatographic separations, and/or extensive sample preparation. Direct mass spectrometry strategies can avoid these requirements, but may also suffer from poor quantitation and/or lack of sensitivity. Condensed phase-membrane introduction mass spectrometry (CP-MIMS) provides direct quantitative measurements of analytes in complex samples with little or no sample preparation. CP-MIMS uses a semipermeable membrane to transfer neutral, hydrophobic compounds from real-world samples to a mass spectrometer. The results presented utilize aqueous/organic sample solvent (donor) mixtures to allow for the sensitive (pptr) detection of a range of fatty acids. The relative sensitivity across a homologous series of fatty acids is observed to change, favoring short- or long-chain fatty acids, depending on the amount of miscible co-solvent added to the donor phase. Further, lithium acetate added online via the acceptor phase was used in tandem mass spectrometry experiments to determine the location of double bonds in polyunsaturated fatty acids (PUFAs). The method was applied to direct measurements and structural determinations for selected PUFAs in salmon tissue samples. Standard addition was employed to quantify the amount of PUFAs in a variety of salmon samples, yielding 0.27–0.42 and 0.40–0.84 w/w % for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively, for Sockeye and Chinook salmon, in good agreement with the literature. This work presents, to our knowledge, the first use of CP-MIMS for the direct analysis of fatty acids in oily foodstuff samples.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Hrbek V, Vaclavik L, Elich O, Hajslova J. Authentication of milk and milk-based foods by direct analysis in real time ionization–high resolution mass spectrometry (DART–HRMS) technique: a critical assessment. Food Control. 2014;36(1):138–45.
Qu S, Du Z, Zhang Y. Direct detection of free fatty acids in edible oils using supercritical fluid chromatography coupled with mass spectrometry. Food Chem. 2015;170:463–9.
Voorhees KJ, Jensen KR, McAlpin CR, Rees JC, Cody R, Ubukata M, et al. Modified MALDI MS fatty acid profiling for bacterial identification. J Mass Spectrom. 2013;48(7):850–5.
Cody RB, McAlpin CR, Cox CR, Jensen KR, Voorhees KJ. Identification of bacteria by fatty acid profiling with direct analysis in real time mass spectrometry. Rapid Commun Mass Spectrom. 2015;29(21):2007–12.
Filimonova V, Gonçalves F, Marques JC, De Troch M, Gonçalves AMM. Fatty acid profiling as bioindicator of chemical stress in marine organisms: a review. Ecol Indic. 2016;67(Suppl. C):657–72.
Calligaris D, Caragacianu D, Liu X, Norton I, Thompson CJ, Richardson AL, et al. Application of desorption electrospray ionization mass spectrometry imaging in breast cancer margin analysis. Proc Natl Acad Sci. 2014;111(42):15184–9.
Valianpour F, Selhorst JJ, van Lint LE, van Gennip AH, Wanders RJ, Kemp S. Analysis of very long-chain fatty acids using electrospray ionization mass spectrometry. Mol Genet Metab. 2003;79(3):189–96.
Trufelli H, Famiglini G, Termopoli V, Cappiello A. Profiling of non-esterified fatty acids in human plasma using liquid chromatography-electron ionization mass spectrometry. Anal Bioanal Chem. 2011;400(9):2933–41.
Swanson D, Block R, Mousa SA. Omega-3 fatty acids EPA and DHA: health benefits throughout life. Adv Nutr. 2012;3(1):1–7.
Dyall SC. Long-chain omega-3 fatty acids and the brain: a review of the independent and shared effects of EPA, DPA and DHA. Front Aging Neurosci. 2015;7:52.
Sprague M, Dick JR, Tocher DR. Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006–2015. Sci Rep. 2016;6:21892.
Chilliard Y, Ferlay A, Doreau M. Effect of different types of forages, animal fat or marine oils in cow’s diet on milk fat secretion and composition, especially conjugated linoleic acid (CLA) and polyunsaturated fatty acids. Livest Prod Sci. 2001;70(1–2):31–48.
Vahmani P, Mapiye C, Prieto N, Rolland DC, McAllister TA, Aalhus JL, et al. The scope for manipulating the polyunsaturated fatty acid content of beef: a review. J Anim Sci Biotechnol. 2015;6(1):29.
Nudda A, Battacone G, Boaventura Neto O, Cannas A, Francesconi AHD, Atzori AS, et al. Feeding strategies to design the fatty acid profile of sheep milk and cheese. R Bras Zootec. 2014;43(8):445–56.
Griffiths WJ. Tandem mass spectrometry in the study of fatty acids, bile acids, and steroids. Mass Spectrom Rev. 2003;22(2):81–152.
Niehaus WG, Ryhage R. Determination of double bond positions in polyunsaturated fatty acids by combination gas chromatography-mass spectrometry. Anal Chem. 1968;40(12):1840–7.
Tomer KB, Crow FW, Gross ML. Location of double-bond position in unsaturated fatty acids by negative ion MS/MS. J Am Chem Soc. 1983;105(16):5487–8.
Eder K. Gas chromatographic analysis of fatty acid methyl esters. J Chromatogr B. 1995;671(1–2):113–31.
Zehethofer N, Pinto DM, Volmer DA. Plasma free fatty acid profiling in a fish oil human intervention study using ultra-performance liquid chromatography/electrospray ionization tandem mass spectrometry. Rapid Commun Mass Spectrom. 2008;22(13):2125–33.
Kortz L, Dorow J, Ceglarek U. Liquid chromatography–tandem mass spectrometry for the analysis of eicosanoids and related lipids in human biological matrices: a review. J Chromatogr B. 2014;964(Suppl. C):1–11.
Cajka T, Fiehn O. Comprehensive analysis of lipids in biological systems by liquid chromatography-mass spectrometry. Trends Anal Chem. 2014;61(Suppl. C):192–206.
Soliman LC, Andrucson EM, Donkor KK, Church JS, Cinel B. Determination of fatty acids in beef by liquid chromatography-electrospray ionization tandem mass spectrometry. Food Anal Methods. 2016;9(3):630–7.
Grebe SK, Singh RJ. LC-MS/MS in the clinical laboratory–where to from here? Clin Biochem Rev. 2011;32(1):5.
Han X, Gross RW. Shotgun lipidomics: electrospray ionization mass spectrometric analysis and quantitation of cellular lipidomes directly from crude extracts of biological samples. Mass Spectrom Rev. 2005;24(3):367–412.
Han X, Yang K, Gross RW. Multi-dimensional mass spectrometry-based shotgun lipidomics and novel strategies for lipidomic analyses. Mass Spectrom Rev. 2012;31(1):134–78.
Schiller J, Süß R, Arnhold J, Fuchs B, Lessig J, Müller M, et al. Matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectrometry in lipid and phospholipid research. Prog Lipid Res. 2004;43(5):449–88.
King R, Bonfiglio R, Fernandez-Metzler C, Miller-Stein C, Olah T. Mechanistic investigation of ionization suppression in electrospray ionization. J Am Soc Mass Spectrom. 2000;11(11):942–50.
Chen H, Gamez G, Zenobi R. What can we learn from ambient ionization techniques? J Am Soc Mass Spectrom. 2009;20(11):1947–63.
Ifa DR, Wu C, Ouyang Z, Cooks RG. Desorption electrospray ionization and other ambient ionization methods: current progress and preview. Analyst. 2010;135(4):669–81.
Awad H, Khamis MM, El-Aneed A. Mass spectrometry, review of the basics: ionization. Appl Spectrosc Rev. 2015;50(2):158–75.
Krogh ET, Gill CG. Membrane introduction mass spectrometry (MIMS): a versatile tool for direct, real-time chemical measurements. J Mass Spectrom. 2014;49(12):1205–13.
Davey NG, Krogh ET, Gill CG. Membrane-introduction mass spectrometry (MIMS). TrAC Trends Anal Chem. 2011;30(9):1477–85.
Johnson RC, Cooks RG, Allen TM, Cisper ME, Hemberger PH. Membrane introduction mass spectrometry: trends and applications. Mass Spectrom Rev. 2000;19(1):1–37.
Duncan K, McCauley E, Krogh E, Gill C. Characterization of a condensed-phase membrane introduction mass spectrometry (CP-MIMS) interface using a methanol acceptor phase coupled with electrospray ionization for the continuous on-line quantitation of polar, low-volatility analytes at trace levels in complex aqueous samples. Rapid Commun Mass Spectrom. 2011;25(9):1141–51.
Duncan KD, Willis MD, Krogh ET, Gill CG. A miniature condensed-phase membrane introduction mass spectrometry (CP-MIMS) probe for direct and on-line measurements of pharmaceuticals and contaminants in small, complex samples. Rapid Commun Mass Spectrom. 2013;27(11):1213–21.
Srinivasan N, Johnson RC, Kasthurikrishnan N, Wong P, Cooks RG. Membrane introduction mass spectrometry. Anal Chim Acta. 1997;350(3):257–71.
Vandergrift GW, Krogh ET, Gill CG. Polymer inclusion membranes with condensed phase membrane introduction mass spectrometry (CP-MIMS): improved analytical response time and sensitivity. Anal Chem. 2017;89(10):5629–36.
Willis MD, Duncan K, Krogh ET, Gill CG. Delicate polydimethylsiloxane hollow fibre membrane interfaces for condensed phase membrane introduction mass spectrometry (CP-MIMS). Rapid Commun Mass Spectrom. 2014;28(7):671–81.
Duncan KD, Vandergrift GW, Krogh ET, Gill CG. Ionization suppression effects with condensed phase membrane introduction mass spectrometry: methods to increase the linear dynamic range and sensitivity. J Mass Spectrom. 2015;50(3):437–43.
Krogh ET, Gill CG. Condensed phase membrane introduction mass spectrometry-continuous, direct and online measurements in complex samples. In: Cappiello A, Palma P, editors. Advances in the use of liquid chromatography mass spectrometry (LC-MS)-instrumentation developments and applications. Comprehensive Analytical Chemistry,vol 79. Elsevier; 2018. p. 173–203.
Cheng C, Gross ML. Applications and mechanisms of charge-remote fragmentation. Mass Spectrom Rev. 2000;19(6):398–420.
Yalkowsky SH, He Y, Jain P. Handbook of aqueous solubility data: CRC press; 2016.
Cistola DP, Hamilton JA, Jackson D, Small DM. Ionization and phase behavior of fatty acids in water: application of the Gibbs phase rule. Biochemistry. 1988;27(6):1881–8.
Wang Y, Ma J, Cheon HS, Kishi Y. Aggregation behavior of tetraenoic fatty acids in aqueous solution. Angew Chem. 2007;119(8):1355–8.
Royal Society of Chemistry. Chemspider. London: Royal Society of Chemistry; 2015. [cited July 21, 2018]. Available from: http://www.chemspider.com/
Wishart DS, Feunang YD, Marcu A, Guo AC, Liang K, Vázquez-Fresno R, et al. HMDB 4.0: the human metabolome database for 2018. Nucleic Acids Res. 2017;46(D1):D608–17.
Duncan KD, Letourneau DR, Vandergrift GW, Jobst K, Reiner E, Gill CG, et al. A semi-quantitative approach for the rapid screening and mass profiling of naphthenic acids directly in contaminated aqueous samples. J Mass Spectrom. 2016;51(1):44–52.
Gelotte KM, Lostritto RT. Solvent interaction with polydimethylsiloxane membranes and its effects on benzocaine solubility and diffusion. Pharm Res. 1990;7(5):523–9.
Twist JN, Zatz JL. A model for alcohol-enhanced permeation through polydimethylsiloxane membranes. J Pharm Sci. 1990;79(1):28–31.
Cussler EL. Diffusion: mass transfer in fluid systems. Cambridge University Press; 2009.
LaPack MA, Tou JC, Enke CG. Membrane mass spectrometry for the direct trace analysis of volatile organic compounds in air and water. Anal Chem. 1990;62(13):1265–71.
Domínguez A, Fernández A, González N, Iglesias E, Montenegro L. Determination of critical micelle concentration of some surfactants by three techniques. J Chem Educ. 1997;74(10):1227–31.
Murphy RC. Tandem mass spectrometry of lipids: molecular analysis of complex lipids. R Soc Chem. 2014.
Adams J, Gross ML. Tandem mass spectrometry for collisional activation of alkali metal-cationized fatty acids: a method for determining double bond location. Anal Chem. 1987;59(11):1576–82.
Jensen NJ, Tomer KB, Gross ML. Gas-phase ion decomposition occurring remote to a charge site. J Am Chem Soc. 1985;107(7):1863–8.
Duncan KD, Volmer DA, Gill CG, Krogh ET. Rapid screening of carboxylic acids from waste and surface waters by ESI-MS/MS using barium ion chemistry and on-line membrane sampling. J Am Soc Mass Spectrom. 2016;27(3):443–50.
Crockett JS, Gross ML, Christie WW, Holman RT. Collisional activation of a series of homoconjugated octadecadienoic acids with fast atom bombardment and tandem mass spectrometry. J Am Soc Mass Spectrom. 1990;1(2):183–91.
Ma X, Chong L, Tian R, Shi R, Hu TY, Ouyang Z, et al. Identification and quantitation of lipid C= C location isomers: a shotgun lipidomics approach enabled by photochemical reaction. Proc Natl Acad Sci. 2016;113(10):2573–8.
Bruce GR, Gill PS. Estimates of precision in a standard additions analysis. J Chem Educ. 1999;76(6):805–7.
US Department of Agriculture. USDA Food Composition Databases. 2018 [cited July 21, 2018]. Available from: https://ndb.nal.usda.gov/ndb/.
Cladis DP, Kleiner AC, Freiser HH, Santerre CR. Fatty acid profiles of commercially available finfish fillets in the United States. Lipids. 2014;49(10):1005–18.
The authors would like to acknowledge the AERL group members Heather Wilson for her contributions to this project as well as Lukas Miner, and Darien Degroot. The authors acknowledge Vancouver Island University and the University of Victoria for their ongoing support of our research. The authors acknowledge technical support for the Q-Sight MS system graciously provided by PerkinElmer.
This study was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC) (Grant # RGPIN-2016-05380 CGG and RGPIN-2016-06454 ETK) and additional funding was provided by the Canada Foundation for Innovation and BC Knowledge Development Fund (CFI #32238).
All fish samples used for this research were obtained as “food” items, and not specifically raised or collected for the purposes of this research. This includes the sport caught Chinook salmon, which was legally obtained as food by fly fishing using a BC Non-Tidal Angling Licence with the appropriate Non-Tidal Salmon Fishing Stamp.
Conflict of interest
The authors declare that they have no conflict of interest.
Electronic supplementary material
About this article
Cite this article
Borden, S.A., Damer, H.N., Krogh, E.T. et al. Direct quantitation and characterization of fatty acids in salmon tissue by condensed phase membrane introduction mass spectrometry (CP-MIMS) using a modified donor phase. Anal Bioanal Chem 411, 291–303 (2019). https://doi.org/10.1007/s00216-018-1467-y
- Long-chain fatty acids
- Membrane introduction mass spectrometry
- Direct mass spectrometry
- Omega-3 fatty acids
- Fatty acid aggregation