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 more than 4 orders of magnitude was observed. An average signal-to-noise ratio (S/N) of 49.6 was observed for 50 attomoles of targeted peptide in the presence of a complex and much more abundant bovine serum albumin (BSA) digest products. A correlation of variation (CV) less than 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.
Revised: December 7, 2012 |
Published: November 10, 2012
Citation
Wang C., C.S. Lee, R.D. Smith, and K. Tang. 2012.Ultrasensitive Sample Quantitation via Selected Reaction Monitoring Using CITP/CZE-ESI-Triple Quadrupole MS.Analytical Chemistry 84, no. 23:10395-10403.PNNL-SA-90482.doi:10.1021/ac302616m