CE coupling with end-column electrochemiluminescence detection for chiral separation of disopyramide

Abstract

CE with electrochemiluminescence (ECL) detection technique was successfully applied for the chiral separation of a kind of class IA antiarrhythmic racemic drug. To the best of our knowledge, this is the first report of ECL detection used in chiral CE. To get better detection sensitivity and good enantioresolution at the same time, the conditions of capillary inlet and outlet buffer were systematically optimized. Unlike the traditional chiral separation method, the buffers we used in the capillary inlet and outlet differed from each other in terms of buffer pH, ionic strength, type of BGE as well as buffer composition. Under the optimum conditions, baseline enantioseparation and highly sensitive detection of the enantiomers were achieved. Wide linear relationship of each enantiomer was achieved in the range of 5 x 10(-7) to 2 x 10(-5) mol/L with relative coefficients of 0.996 and 0.997, respectively. The detection limits were estimated to be 8 x 10(-8) and 1.0 x 10(-7) mol/L (S/N = 3) for the enantiomers, respectively. In addition, a successful application of this new method to the chiral separation of the racemic drug in spiked plasma samples confirmed the validity and applicability of the chiral CE-ECL method.

Sensitive chiral analysis by CE: An update

“…Thus, Table 1 shows the use of LLE for the determination of drugs in biological samples as plasma [20][21][22][23], human serum [17,19], human urine [17], and a microsomal fraction of liver homogenates [18]. Preconcentration factors up to 21 were achieved by this extraction procedure.…”

“…ECL was also used as an attractive detection method for chiral CE [23]. This detection technique has comparative sensitivity to LIF and MS detection.…”

Review of aqueous chiral electrokinetic chromatography (EKC) with an emphasis on chiral microemulsion EKC

“…unique approach to chiral CE was taken by Fang et al [126] for the discrimination of disopyramide enantiomers (S-b-CD) by using electrochemiluminescence detection with the visualization agent tris-(2,2 0 -bipyridyl)-ruthenium. In another departure from the generally utilized set-up, the solutions in the inlet and outlet buffer vials were optimized with their final conditions varying in pH and ionic strength (chiral selector was present only in the inlet vial).…”

Advanced CE for chiral analysis of drugs, metabolites, and biomarkers in biological samples

“…Ionic character of these CD derivatives is responsible for their excellent water solubility. Enhanced enantiomeric recognition as well as solubility of these CDs and their complexes in comparison with their native forms was illustrated on many biological samples (urine, squirrel brain, human plasma), including carboxyethyl-b-CD versus H 1 -antihistaminic drugs (dioxopromethazine, dimethindene, pheniramine) [49,50,121], a highly sulfated-b-CD versus CBI derivatives of serine, glutamate, and aspartate [122], a highly sulfated-b-CD versus CBIderivatized baclofen [73], a highly sulfated-b-CD versus a racemic antiarrhythmic drug (disopyramide) [74], for details see Table 1.…”