Ion-pair chromatography and micellar electrokinetic capillary chromatography in analyzing beta-adrenergic blocking agents from human biological fluids.
Ion-pair chromatography (IPC) and micellar electrokinetic capillary chromatography (MECC) were used for the separation and determination of parent beta-blockers from human biological fluids. In both these techniques, N-cetyl-N,N,N-trimethylammonium bromide (CTAB) was used as a buffer additive. In IPC, CTAB was an ion-pair former, and in MECC it was a micelle-forming surfactant. The effectiveness of the IPC method using methanol-gradient elution and that of MECC were compared for drug-spiked serum and urine samples. Detection was performed with a diode-array detector in the IPC method and with a 214-nm filter in the MECC technique. In both methods a phosphate buffer (pH 7.0) was used. In MECC the buffer solution contained 10 mM CTAB, while in IPC the CTAB concentration was decreased from 7 to 4 mM during the separation when a methanol gradient was used. The study showed that the IPC technique performed better for bioanalyses than the high-performance MECC technique, since in MECC UV detection presented a problem because of the low sample concentration. However, in MECC sample preparation was less time-consuming, using hydrolyzation and protein precipitation and, unlike the IPC technique, it did not require any liquid-liquid extraction step.
Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, Finland.
P
P
Lukkari
H
H
Sirén
D000319:Adrenergic beta-Antagonists / Q000097:blood* / Q000652:urine*; D002853:Chromatography, Liquid / Q000379:methods*; D004563:Electrochemistry; D006801:Humans; D007477:Ions; D008823:Micelles; D013056:Spectrophotometry, Ultraviolet
D000319:Adrenergic beta-Antagonists; D007477:Ions; D008823:Micelles