title: Microwave-accelerated derivatization for capillary electrophoresis with laser-induced fluorescence detection: a case study for determination of histidine, 1- and 3-methylhistidine in human urine.
abstract: The feasibility of microwave-accelerated derivatization for capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection was evaluated. The derivatization reaction was performed in a domestic microwave oven. Histidine (His), 1-methylhistidine (1-MH) and 3-methylhistidine (3-MH) were selected as test analytes and fluorescein isothiocyanate (FITC) was chosen as a fluorescent derivatizing reagent. Parameters that may affect the derivatization reaction and/or subsequent CE separation were systematically investigated. Under optimized conditions, the microwave-accelerated derivatization reaction was successfully completed within 150 s, compared to 4-24 h in a conventional water-bath derivatization process. This will remarkably reduce the overall analysis time and increase sample throughput of CE-LIF. The detection limits of this method were found to be 0.023 ng/mL for His, 0.023 ng/mL for 1-MH, and 0.034 ng/mL for 3-MH, respectively, comparable to those obtained using traditional derivatization protocols. The proposed method was characterized in terms of precision, linearity, accuracy and successfully applied for rapid and sensitive determination of these analytes in human urine.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Department of Chemistry, Lanzhou University, 222 Southern Tianshui Road, Lanzhou 730000, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhou
authors.forename: Na
authors.initials: N
authors.lastname: Yan
authors.forename: Huige
authors.initials: H
authors.lastname: Zhang
authors.forename: Ximin
authors.initials: X
authors.lastname: Zhou
authors.forename: Qiaosheng
authors.initials: Q
authors.lastname: Pu
authors.forename: Zhide
authors.initials: Z
authors.lastname: Hu
mesh_terms: D002021:Buffers; D019075:Electrophoresis, Capillary / Q000379:methods*; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D006639:Histidine / Q000031:analogs & derivatives* / Q000652:urine*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007834:Lasers; D057230:Limit of Detection; D016014:Linear Models; D008762:Methylhistidines / Q000652:urine; D008872:Microwaves; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013997:Time Factors; D016482:Urinalysis / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D002021:Buffers; D008762:Methylhistidines; D014867:Water; C028120:1-methylhistidine; D006639:Histidine; D016650:Fluorescein-5-isothiocyanate; C028118:3-methylhistidine