title: Laser desorption/ionization mass spectrometric analysis of surfactants on functionalized carbon nanotubes.
abstract: BACKGROUND
  Recently, unmodified and carboxylated carbon nanotubes have been used as assisting surfaces laser desorption/ionization (LDI) in mass spectrometry. The functionalization of carbon nanotubes with organic compounds should lead to a gamut of other promising LDI-assisting surfaces.
  
  
  METHODS
  Carboxylated carbon nanotubes were functionalized with sinapinic acid either covalently or by creating an ionic macro-complex. Polyether-based surfactants were used as analytes to examine the properties of these new matrices. Mass spectrometric analysis was conducted on a LDI-quadrupole time-of-flight (QTOF) mass spectrometer. Carbon nanotube surfaces were deposited from suspension using the dried-droplet method.
  
  
  RESULTS
  The functionalization of the carbon nanotubes was confirmed with Fourier transform infrared (FTIR) spectroscopy. The usefulness of each material was examined with two poly(ethylene glycol) hexadecyl ether amphiphiles (Brij® 52 and Brij® 56) and a poly(ethylene glycol) monomethyl ether as analytes. Generally, the mass spectra obtained with carbon nanotubes covalently functionalized with sinapinic acid as a matrix had peaks with higher intensities than those obtained with carbon nanotubes functionalized by ionic macro-complex formation.
  
  
  CONCLUSIONS
  The presented new materials based on functionalized carbon nanotubes are effective in the LDI mass analysis of polyether amphiphiles and poly(ethylene glycol) monomethyl ether. This type of assisting surfaces can be highly modified by appropriate functionalization procedures.
authors.affiliation: Faculty of Chemistry, Adam Mickiewicz University in Poznan, Umultowska 89b, 61-614, Poznań, Poland. ceglowski.m@gmail.com
authors.forename: Michał
authors.initials: M
authors.lastname: Cegłowski
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Schroeder