Separation of related opiate compounds using capillary electrochromatography

• Published in: Electrophoresis 2000-03, Vol.21 (4), p.737-742
• Main Authors: Lim, Jong-Tae, Zare, Richard N., Bailey, Christopher G., Rakestraw, David J., Yan, Chao
• Format: Article
• Language: English
• Subjects: Analgesics, Opioid - chemistry; Analgesics, Opioid - isolation & purification; Capillary electrochromatography; Electrophoresis, Capillary - methods; Indicators and Reagents; Micellar electrokinetic chromatography; Narcotics - isolation & purification; Opiate drugs; Reproducibility of Results; Sensitivity and Specificity
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/(SICI)1522-2683(20000301)21:4<737::AID-ELPS737>3.0.CO;2-Q

Capillary electrophoretic separations have been investigated for six controlled narcotic analgesic compounds having related structures. Owing to the similar charge‐to‐mass ratios of these compounds, capillary zone electrophoresis failed to provide a satisfactory separation, whereas a baseline‐resolved separation was achieved in 10 min using micellar electrokinetic chromatography. Column efficiencies of 40 000—150 000 plates/m were obtained with a 50 cm long, 50 μm inner diameter (ID) capillary using 50 mM sodium dodecyl sulfate (SDS) in a 50 mM borate solution containing 12% isopropanol. In contrast, separation of this mixture by capillary electrochromatography proved to be significantly superior. The capillary was 15 cm long, with an ID of 75 μm, and was packed with 1.5 μm nonporous octadecyl silica (ODS) particles. The mobile phase consisted of 80% 10 mM tris(hydroxymethyl)aminomethane (Tris) and 20% acetonitrile, and contained 5 mM SDS. A complete separation was obtained in 2.5 min with an efficiency of 250000—500000 plates/m.