title: Pepsin-modified chiral monolithic column for affinity capillary electrochromatography.
abstract: Pepsin-modified affinity monolithic capillary electrochromatography, a novel microanalysis system, was developed by the covalent bonding of pepsin on silica monolith. The column was successfully applied in the chiral separation of (±)-nefopam. Furthermore, the electrochromatographic performance of the pepsin-functionalized monolith for enantiomeric analysis was evaluated in terms of protein content, pH of running buffer, sample volume, buffer concentration, applied voltage, and capillary temperature. The relative standard deviation (%RSD) values of retention time (intraday <0.53, n = 10; interday <0.53, n = 10; column-to-column <0.70, n = 20; and batch-to-batch <0.80, n = 20) indicated satisfactory stability of these columns. No appreciable change was observed in retention and resolution for chiral recognition of (±)-nefopam in 50 days with 100 injections. The proteolytic activity of this stationary phase was further characterized with bovine serum albumin as substrate for online protein digestion. As for monolithic immobilized enzyme reactor, successive protein injections confirmed both the operational stability and ability to reuse the bioreactor for at least 20 digestions. It implied that the affinity monolith used in this research opens a new path of exploring particularly versatile class of enzymes to develop enzyme-modified affinity capillary monolith for enantioseparation.
authors.affiliation: Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Hong
authors.forename: Cuijie
authors.initials: C
authors.lastname: Chi
authors.forename: Yibing
authors.initials: Y
authors.lastname: Ji
mesh_terms: D000700:Analgesics / Q000032:analysis; D000818:Animals; D019149:Bioreactors; D002021:Buffers; D002417:Cattle; D002744:Chlorpheniramine / Q000737:chemistry; D002846:Chromatography, Affinity; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D009340:Nefopam / Q000737:chemistry*; D010434:Pepsin A / Q000737:chemistry*; D015203:Reproducibility of Results; D012709:Serum Albumin / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D000700:Analgesics; D002021:Buffers; D012709:Serum Albumin; D002744:Chlorpheniramine; D009340:Nefopam; D012822:Silicon Dioxide; D010434:Pepsin A
keywords: Affinity electrochromatography; Capillary monoliths; Enantiomeric separation; Pepsin; Silica