Lipids analysis by 2 dimensional LC coupled with triple quadrupole mass spectrometer

We have constructed a 2-D LC-ESI-MS/MS system. This system comprises 3 flow lines: one for primary class separation by normal phase column (1D), another for concentration, and the third for secondary separation by reverse phase column (2D).
A sample solution of GPLs mixture was loaded into a normal phase column and only the fractions of interest are selected from the effluent of the 1D separation and transferred to the 2D separation. At the start point of the fraction, two 2-position valves are serially switched and the effluent from the 1D column is automatically mixed with diluent and introduced into a trapping column intended to retain sample in a narrow zone. At the end point of the fraction, concentrated target class of GPLs are introduced into reverse phase column connected in series to obtain resulting chromatograms. This system offers automated target GPLs concentration and removal of undesired metabolites.Using a 1D and 2D column with different retention characteristics, or using different mobile phase compositions, permits reliable separation of various classes of GPLs. By connecting this 2-D LC system and triple quadropole MS instrument, high resolution analysis is performed. This method was successfully applied to a GPLs mixture.