Liquid chromatography-electrospray mass spectrometry and tandem mass spectrometry of ceramides

A quantitative liquid chromatography-mass spectrometry (LC/MS) method desig ned for the rapid, sensitive and specific analytical determination of all k inds of ceramides is described. LC separation was carried out on a RP 18 co lumn (2 mm i.d., 3 mu m particle size) using an isocratic mobile phase (met hanol/tetrahydrofuran 97:3) in less than 8 min. LC/MS and LC/MS/MS were per formed on an ion trap instrument and were compared to results obtained usin g a single quadrupole instrument. In the negative ionization mode a limit o f detection of approx. 500 pg/ml was reached. The quantification using exte rnal standards showed good linearity over three orders of magnitude and a r elative standard deviation of 3%. The use of Tandem MS and MS3 for obtainin g structural information was demonstrated on the ion trap instrument and co mpared to results achieved on a triple quadrupole instrument. (C) 2000 Else vier Science B.V. All rights reserved.