title: Insights into cyclodextrin interactions during sample stacking using capillary isotachophoresis with on-line microcoil NMR detection.
abstract: On-line capillary isotachophoresis (cITP)-NMR experiments were used to probe the interactions of the pharmaceutical compounds S-alprenolol, S-atenolol, R-propranolol, R-salbutamol and S-terbutaline with beta-cyclodextrin (beta-CD) during cITP concentration. In cITP, ionic analytes are concentrated and separated on the basis of their electrophoretic mobility. Because neutral molecules have an electrophoretic mobility of zero, they are normally not concentrated or separated in electrophoretic experiments like cITP. Most of the analytes studied were concentrated by cITP sample stacking by a factor of around 300. For analytes that formed a strong inclusion complex, beta-CD co-concentrated during cITP sample stacking. However, once the focusing process was complete, a discrete diffusional boundary formed between the cITP-focused analyte band and the leading and trailing electrolyte, which restricted diffusion into and out of the analyte band.
authors.affiliation: Department of Chemistry, University of Kansas, Lawrence, 66045, USA.
authors.forename: Valentino K
authors.initials: VK
authors.lastname: Almeida
authors.forename: Cynthia K
authors.initials: CK
authors.lastname: Larive
mesh_terms: D000420:Albuterol / Q000032:analysis / Q000737:chemistry; D000526:Alprenolol / Q000032:analysis / Q000737:chemistry; D001262:Atenolol / Q000032:analysis / Q000737:chemistry; D003505:Cyclodextrins / Q000032:analysis* / Q000737:chemistry; D004058:Diffusion; D004573:Electrolytes / Q000737:chemistry; D004586:Electrophoresis / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011433:Propranolol / Q000032:analysis / Q000737:chemistry; D011522:Protons; D012680:Sensitivity and Specificity; D013726:Terbutaline / Q000032:analysis / Q000737:chemistry
chemical_list: D003505:Cyclodextrins; D004573:Electrolytes; D011522:Protons; D001262:Atenolol; D000526:Alprenolol; D011433:Propranolol; D013726:Terbutaline; D000420:Albuterol