An analytical method to improve the characterization of lipoprotein fractions is presented. Human plasma samples were treated with Sudan Black B to stain the lipid component in lipoproteins, then the stained lipoproteins were separated by frit inlet asymmetrical flow field-flow fractionation (FI-AFlFFF), according to the lipoprotein particle sizes, with the selective detection of eluting lipoprotein fractions, high-density lipoproteins (HDL), low-density lipoproteins (LDL) and very-low-density lipoproteins (VLDL), at 610 nm. The capability of this technique has been evaluated with plasma samples obtained from patients with coronary artery disease (CAD), and it showed that the retention profile of patients' lipoprotein samples was clearly distinct from those of healthy persons. The potential of this technique comes with the direct injection of a stained lipoprotein sample without a prior procedure such as ultracentrifugation for sample preparation, and the size calculation of lipoprotein particles from the experimental retention time by theory. Since sample relaxation was achieved hydrodynamically in an FI-AFlFFF channel, sample injection and separation processes were continuously made without stopping the separation flow. This study demonstrated the potential of the FI-AFlFFF technique to be utilized as a powerful tool for the determination of the LDL profiles of patients with CAD.
Copyright 2002 Elsevier Science B.V.