title: Ultrasensitive sample quantitation via selected reaction monitoring using CITP/CZE-ESI-triple quadrupole MS.
abstract: We demonstrate the direct coupling of transient capillary isotachophoresis/capillary zone electrophoresis (CITP/CZE) with a high-sensitivity triple quadrupole mass spectrometer operating in selected reaction monitoring (SRM) mode for sample quantitation. The capability of CITP/CZE for in situ sample enrichment and separation has been shown to significantly improve the analytical figures of merit. A linear dynamic range spanning 4 orders of magnitude was observed. An average signal-to-noise ratio (S/N) of 49.6 was observed for 50 amol of targeted peptide in the presence of a complex and much more abundant bovine serum albumin (BSA) digest. Correlation of variation (CV) of <10% for peak area was measured from triplicate sample analyses at 50 pM peptide concentration, showing good reproducibility of this online CITP/CZE-SRM mass spectrometry (MS) platform, and with limit of quantitation (LOQ) demonstrated to be well below 50 pM.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, College Park, 20742, United States.
authors.forename: Chenchen
authors.initials: C
authors.lastname: Wang
authors.forename: Cheng S
authors.initials: CS
authors.lastname: Lee
authors.forename: Richard D
authors.initials: RD
authors.lastname: Smith
authors.forename: Keqi
authors.initials: K
authors.lastname: Tang
mesh_terms: D000818:Animals; D002417:Cattle; D019075:Electrophoresis, Capillary; D006801:Humans; D057625:Isotachophoresis; D010446:Peptide Fragments / Q000032:analysis*; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine / Q000032:analysis*; D059629:Signal-To-Noise Ratio; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D010446:Peptide Fragments; D012710:Serum Albumin, Bovine