title: Analysis of low molecular weight acids by monolithic immobilized pH gradient-based capillary isoelectric focusing coupled with mass spectrometry.
abstract: A novel method for the separation and detection of low molecular weight (LMW) acids was developed using monolithic immobilized pH gradient-based capillary isoelectric focusing coupled with mass spectrometry. Two main parameters, focusing conditions and delivery buffer conditions, which might affect separation efficiency, were optimized with the focusing time of 7 min at 350 V/cm and the delivery buffer of 50% (v/v) acetonitrile in 10 mmol/L ammonium formate (pH 3.0). Under these conditions, the linear correlation between the volume of delivery solvent and the pK(a) of the model components was observed. In addition, the separation mechanism of LMW acids was proposed as well. We suppose that this method may provide a useful tool for the characterization of LMW components (e.g. natural organic matter of different origins).
authors.affiliation: Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic Research and Analysis Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, PR China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Wang
authors.forename: Agnes
authors.initials: A
authors.lastname: Fekete
authors.forename: Andras
authors.initials: A
authors.lastname: Gaspar
authors.forename: Junfeng
authors.initials: J
authors.lastname: Ma
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liang
authors.forename: Huiming
authors.initials: H
authors.lastname: Yuan
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.forename: Philippe
authors.initials: P
authors.lastname: Schmitt-Kopplin
authors.forename: Yukui
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000143:Acids / Q000737:chemistry* / Q000302:isolation & purification*; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D007525:Isoelectric Focusing / Q000295:instrumentation / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D018892:Proton-Motive Force
chemical_list: D000143:Acids