title: On-stage liquid-phase lipid microextraction coupled to nanospray mass spectrometry for detailed, nano-scale lipid analysis.
abstract: BACKGROUND
  Developments in instrumentation aimed at microscopic sampling have led to an emphasis on applications analyzing small volumes and molecular concentrations within biological, chemical, and industrial samples. Simultaneous improvements in the sensitivity and versatility of nanospray mass spectrometers have made it possible to directly couple these sampling and analysis processes.
  
  
  METHODS
  We developed a versatile liquid-phase lipid microextraction (LPME) technique for nanoliter to microliter volumes that is amenable to direct nanospray mass spectrometry (NMS). Lipophilic analytes within several types of biological samples were extracted and analyzed by partitioning and concentrating the analytes based on their solubility within two immiscible or partially miscible liquid phases.
  
  
  RESULTS
  The utility of LPME-NMS is demonstrated by extracting and analyzing molecules in four different types of applications: (1) visualization of an extracted neutral lipid-specific fluorescent dye from an aqueous solvent; (2) identification of controlled acid-catalyzed hydrolysis of triacylglycerols within nanospray capillaries; (3) reproducible sampling of a fatty acid emulsion; and (4) profiling of diverse lipids in a complex biological matrix of rabbit serum.
  
  
  CONCLUSIONS
  The modified instrumentation of a multi-port, on-stage bioworkstation shows considerable versatility by combining nanomanipulation, microextraction and direct NMS for a variety of chemical, biological, industrial, and clinical applications.
authors.affiliation: Center for Plant Lipid Research, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Horn
authors.forename: Ubisha
authors.initials: U
authors.lastname: Joshi
authors.forename: Anna K
authors.initials: AK
authors.lastname: Behrendt
authors.forename: Kent D
authors.initials: KD
authors.lastname: Chapman
authors.forename: Guido F
authors.initials: GF
authors.lastname: Verbeck
mesh_terms: D000818:Animals; D008055:Lipids / Q000097:blood / Q000737:chemistry* / Q000302:isolation & purification; D059627:Liquid Phase Microextraction / Q000379:methods*; D013058:Mass Spectrometry; D011817:Rabbits
chemical_list: D008055:Lipids