title: Direct analysis of triacylglycerols from crude lipid mixtures by gold nanoparticle-assisted laser desorption/ionization mass spectrometry.
abstract: Triacylglycerols (TAGs), essential energy storage lipids, are easily detected by conventional MALDI MS when occurring on their own. However, their signals are easily overwhelmed by other lipids, mainly phosphatidylcholines (PCs) and, therefore, require purification. In order to profile TAGs from crude lipid mixtures without prefractionation, we investigated alternative matrixes that can suppress phospholipid ion signals and enhance cationization of TAGs. We found that an aqueous solution of citrate-capped gold nanoparticles (AuNPs) with a diameter of 12 nm is a superior matrix for the laser desorption/ionization mass spectrometry (LDI MS) of TAGs in crude lipid mixtures. The AuNP matrix effectively suppressed other lipid signals such as phospholipids and also provided 100 times lower detection limit for TAGs than 2,5-dihydroxybenzoic acid (DHB), the best conventional MALDI matrix for TAGs. The AuNP-assisted LDI MS enabled us to obtain detailed TAG profiles including minor species directly from crude beef lipid extracts without phospholipid interference. In addition, we could detect TAGs at a trace level from a total brain lipid extract.
authors.affiliation: Department of Chemistry, Hankuk University of Foreign Studies, Yongin, 449-791, Korea.
authors.forename: Jeongjin
authors.initials: J
authors.lastname: Son
authors.forename: Gwangbin
authors.initials: G
authors.lastname: Lee
authors.forename: Sangwon
authors.initials: S
authors.lastname: Cha
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002417:Cattle; D019343:Citric Acid / Q000737:chemistry; D045424:Complex Mixtures / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D015203:Reproducibility of Results; D012995:Solubility; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013499:Surface Properties; D034421:Sus scrofa; D014280:Triglycerides / Q000032:analysis*
chemical_list: D045424:Complex Mixtures; D007202:Indicators and Reagents; D014280:Triglycerides; D019343:Citric Acid; D006046:Gold