Improved LC-MS method for the determination of fatty acids in red blood cells by LC-orbitrap MS

Anal Chem. 2011 Apr 15;83(8):3192-8. doi: 10.1021/ac103093w. Epub 2011 Mar 23.


We report a new method for fast and sensitive analyses of biologically relevant fatty acids (FAs) in red blood cells (RBC) by liquid chromatography mass spectrometry (LC-MS). A new chemical derivatization approach was developed forming picolylamides from FAs in a quantitative reaction. Fourteen derivatized FA standards, including saturated and unsaturated FAs from C14 to C22, were efficiently separated within 15 min. In addition, the use of a recently introduced benchtop orbitrap mass spectrometer under positive electrospray ionization (ESI) full scan mode showed a 2-10-fold improvement in sensitivity compared with a conventional tandem MS method, with a limit of detection in the low femtomole range for saturated and unsaturated FAs. The developed method was applied to determine FA concentrations in RBC with intra- and interday coefficients of variation below 10%.

MeSH terms

  • Amides / chemical synthesis
  • Amides / chemistry
  • Chromatography, High Pressure Liquid / methods*
  • Erythrocytes / chemistry*
  • Fatty Acids / analysis*
  • Humans
  • Molecular Structure
  • Spectrometry, Mass, Electrospray Ionization / methods*
  • Stereoisomerism


  • Amides
  • Fatty Acids