Cyclodextrin‐micellar electrokinetic chromatography of apolipoproteins on human very low‐density lipoprotein

Abstract

The apolipoproteins (APOs) of human very low‐density lipoprotein (VLDL) were investigated by an optimized cyclodextrin‐micellar electrokinetic chromatography (CD‐MEKC) method. The separation buffer consisted of 20 mM sodium phosphate, 40 mM bile salts (50% sodium cholate and 50% sodium deoxycholate), 25 mM carboxymethyl‐β‐cyclodextrin (CM‐β‐CD) (pH 7.0). For CD‐MEKC separation, a sample injection time of 12 s, a separation voltage of 15 KV, and a capillary temperature of 15°C were chosen. The optimal CD‐MEKC method showed good resolution and repeatability for VLDL APOs. Identification and quantitation of VLDL APOs CI, CIII, and E were based on comparison with human APO standards. Good linear relationships with correlation coefficient (R2) 0.99 were obtained for APOs CI, CIII, and E standards. For these three APOs, the linear ranges were within 0.01‐0.54 mg/mL, and the concentration limits of detection (LODs) were lower than 0.02 mg/mL. Moreover, VLDL APOs from four uremic patients and four healthy subjects were compared. The uremic and healthy CD‐MEKC profiles showed dramatic difference. The levels of APO CIII were significantly higher for two patients, and the level of APO E was significantly higher for one patient. This study might be helpful for following the disease development of uremia and cardiovascular disease (CVD) in the future.

Strategies for capillary electrophoresis: Method development and validation for pharmaceutical and biological applications—Updated and completely revised edition

“…Here, the optimum BGE was composed of 50 mM sodium phosphate, pH 9 and 30 mM SDS; allowing the analysis of ethanol, butanol, and pentanol with limit of detections (LODs) of 0.17%, 0.18%, and 0.50%, respectively [51]. Table 2 [28,42,44,45,49,[52][53][54][55][56][57][58][59] provides additional examples of combinations of BGEs optimized for the separation of specific analytes.…”