title: Sensitive absorption-based wave-mixing detector for anthracycline drugs separated by capillary electrophoresis.
abstract: Sensitive absorption-based detection of anthracycline antibiotics, daunorubicin and doxorubicin is demonstrated using a capillary electrophoresis system interfaced to a nonlinear wave-mixing detection system. Unlike conventional absorption methods, this nonlinear absorption method can detect very thin analytes (50 microm) efficiently. At the same peak height, the wave-mixing CE peak is narrower than a conventional CE peak, and hence, compared to other laser-based or non-laser-based CE on-column detection methods, our wave-mixing detection method offers intrinsically enhanced separation resolution even when using identical CE separation conditions. In this unusually sensitive "absorbance" detection method, two input laser beams interact to produce a thermally induced grating from which coherent laser-like wave-mixing signal beams are created. Using our sensitive "absorbance" on-column CE detector, we report a preliminary concentration detection limit of 9.9x10(-10)M using a 50-mum i.d. capillary column. The corresponding "injected" mass detection limit is 9.1x10(-18)mol using an injection volume of 9.2nL. The corresponding preliminary "detected" mass detection limit inside the 12-pL detector probe volume is 1.2x10(-20)M.
authors.affiliation: Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182, USA.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Berniolles
authors.forename: Hongjing
authors.initials: H
authors.lastname: Kan
authors.forename: William G
authors.initials: WG
authors.lastname: Tong
mesh_terms: D000042:Absorption; D018943:Anthracyclines / Q000032:analysis*; D000903:Antibiotics, Antineoplastic / Q000032:analysis; D003630:Daunorubicin / Q000032:analysis; D004317:Doxorubicin / Q000032:analysis; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D007834:Lasers; D057230:Limit of Detection; D004364:Pharmaceutical Preparations / Q000737:chemistry*
chemical_list: D018943:Anthracyclines; D000903:Antibiotics, Antineoplastic; D004364:Pharmaceutical Preparations; D004317:Doxorubicin; D003630:Daunorubicin