Methyl-beta-cyclodextrin modified micellar electrokinetic capillary chromatography with laser-induced fluorescence for separation and detection of phospholipids

Micellar electrokinetic capillary chromatography (MECC) with laser-induced fluorescence detection was applied to the separation of amino group-contain ing phospholipids including phosphatidylethanolamine (PE), phosphatidylseri ne (PS), lysophosphatidylethanolamine (LysoPE), and lysophosphatidylserine (LysoPS). A fluorogenic dye, 3-(2-furoyl)quinoline-2-carboxaldehyde (FQ), w as successfully used to fluorescently label these phospholipids, 4-Fluoro-7 -nitrobenzofurazan only produced fluorescent product from LysoPE and PE; si gnals were not observed from LysoPS and PS. A borax buffer containing sodiu m deoxycholate modified with methyl-beta-cyclodextrin (methyl-beta-CD) was an excellent MECC system for these phospholipids. Under the optimum conditi ons, four FQ-labeled phospholipid classes were separated within 8 min. More over, each of the PE, PS, LysoPE and LysoPS peaks split into two components corresponding to subclasses with different lengths of the fatty acid chain s, but these subclasses were completely resolved only for LysoPE. Detection limits ranged from 0.18 to 1.1 fg (10(-9)-10(-10) M), which was four- to f ive-orders of magnitude superior to previously reported CE methods. (C) 200 0 Elsevier Science B.V. All rights reserved.