The Application Of Novel CE-HRMS In Analysis Of Complex Samples

The analysis of complex samples is becoming the new concern in the field of analytic science. In this paper. Capillary Electrokinetic Fractionation (CEkF) is investigated as a new, simple and robust approach for semi-preparative and analytical sample analysis based on pKa-dependant pH-driven electrophoretic mobility, at-line coulping with High Resolution Mass Spectrometry (HRMS) for the meaningful molecular understanding of complex samples.In chap 1, the definition and features of complex samples, the advantages of the coupling of capillary electrophoresis and mass spectrometry was reviewed. In addition, the theory, feasibility and design of CEkF were introduced.In chap 2, we propose a semi-empirical model with 14 representative compounds based on the correlation between sample/medium pH regulating the partial charge, the electrokinetic loading of the capillary and intensity (Ⅰ) of analytes. According to the model, an empirical function (I= f (pH)) could be derived to calculate the acid dissociation constant (pKa) of various model compounds based on their pH-dependant MS intensity profiles with the RSD less than 4.05.In chap 3, using the ultrahigh resolution of ion cyclotron Fourier transform mass spectrometry (ICR-FT/MS), the pKa model was further illustrated in real samples into the structure prediction of important compounds in wine over 2 vintages. The established CEkF was successfully used to selectively fractionate sulfur compounds from the complex wine samples at pH 1.66. The proposed CEkF approach should allow in the future the simultaneous ipKa evaluation of multiple constituents without complicated separation out of a complex mixture in metabolomics or environmental chemistry.In chap 4, CEkF was coupled at-line with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS) to isolate and characterize OS compounds in WSOC fractions of biomass burning from boreal forest and urban PM2.5 aerosols. In a mass range of m/z 190-400, more than 500 CHOS-and CHONS-compounds were unambiguously identified in the CHONS compositional space.In chap 5, CEKF was at-line combined with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and Nuclear magnetic resonance (NMR) for the fraction characterization of Suwannee River fulvic acid (SRFA). By screening the collected fractionations over all the pH range (pH 1.9-10.5), we sorted out the constituents of SRFA according to their different dissociation directly relating to the functional groups. To our knowledge, this is the first application of CEkF coupling with NMR in the structural details description of this highly complex mixture.In chap 6, FASS was introduced as an on-line oncentration to combine with CE-ESI/MS and achieve the trace analysis of microcystin (MC) isomers in crude algae sample. The combination of FASS and CE-ESI/MS was also applied to analyze the β2-agonists hinuman urine samples successfully.In chap 7, the stability of a shellfish poisoning agent:domoic acid (DA) was investigated with HPLC-QqQ MS. Under the optimal conditions, DA in seawater samples and shellfish samples has been successfully detected by using HPLC-QqQ MS.