Professor Vouros’ research programs in the development and applications of capillary LC-MS/MS techniques (and CE-MS/MS) for the analysis of biomolecules include a number of active collaborations with clinical/biomedical colleagues in the U.S. and overseas. A main focus is the development of LC(CE)-MS/MS methods for the detection of biomarkers indicative of exposure to environmental carcinogens or of other biological processes. A major collaboration includes two joint NIH grants with the University of Kentucky Medical School, Lexington.   In work conducted under support from a third recently awarded NIH grant, we are investigating by micro-capillary LC-MS/MS the formation of DNA adducts in tissues of animals and humans exposed to carcinogens present in diet and cigarette smoke (below). Work is also continuing in the areas of High-Throughput Screening and of vitamin D analysis, investigating the significance of metabolic pathways that were recently elucidated in our laboratory.  A new program, in collaboration with Dr. Helmut Zarbl of the Fred Hutchinson Cancer Center, Seattle, is investigating the relationship between DNA adduct formation and toxicogenomic processes (Zarbl, below).

Two exciting new techniques under development include Differential Ion Mobility and the NanoSplitter, which can increase sensitivity up to 1000-fold in coupling MS toconventional-scale LC, and is being applied in pharmaceutical analysis and, combined with microcoil NMR, to natural products identification.

Trace level analysis of DNA adducts from environmental (industrial, cigarette smoke and food borne) carcinogens as a means for assessing cancer risk from exposure.
Investigation of the relationship between DNA adduct formation and toxicogenomic processes (in collaboration with Dr. Helmut Zarbl of the Fred Hutchinson Cancer Center, Seattle, WA)


  • Mutation, Gene Expression and DNA Adduct Formation in Human Lymphoblast Cells Dosed with Benzo[a]pyrene and 4-aminobiphenyl.  Elaine M. Ricicki*, Wendy Luo, Helmut Zarbl and Paul Vouros.   Summary
  • Phenotypic Anchoring of Global Gene Expression Profiles Induced by N-hydroxy-4-acetylaminobiphenyl and Benzo(a)pyrene  Diol Epoxide Reveals  Correlations between Expression Profiles and Mechanism of Toxicity.   Luo, W., Fan, W., Xie, H., Jing, L.; Zhao, L.P., Ricicki, E., Vouros, P. and Zarbl, H.,  Chem. Res. Toxicol. 18, 619-629 ( 2005). Pubmed

Differential ion mobility interfaced to mass spectrometry to improve separations of biomolecules and MS sensitivity.

  • A novel nanoESI-DMS-MS system for characterizing gas phase molecular interaction mechanisms and their use in predicting differential mobility behavior.  Daren S. Levin and Paul Vouros.   Presentation Slides

Studies in drug metabolism and high throughput screening of combinatorial libraries.

  • High Throughput Medicinal Library Screening against Human Serum Albumin  Jimmy Flarakos, Paul Vouros, Kenny Morand.  Summary
  • The Comparative Analysis of Risperidone and it 9-hydroxy-metabolite using High Resolution Quadrupole Mass Spectrometry with Accurate Mass and Time-of- Flight Mass Spectrometry. Edward Daly, Jimmy Flarakos, et al.   Summary

Natural Products Identification by LC-UV-MS-NMR:  Trace Detection With On-Line LC-MS Using the NanoSplitter and Off-Line Microcoil LC-NMR 
Roger Kautz, Jimmy Orjala, and Paul Vouros

The Nano Splitter:  1000-fold Sensitivity Enhancement in Coupling Traditional-Scale LC to MS Detection.

  • Reduction of signal suppression effects in ESI-MS using a nanosplitting device. Gangl ET, Annan MM, Spooner N, Vouros P.  Anal. Chem. 2001,  73:5635-44
  • Fluid NanoSplitter Device,  Eric Gangl and Paul Vouros, Inventors, US Patent No. 6817554, Issued November 16, 2004
  • The Effect of Concentric Post-Column Splitting on Detection and Ion Suppression in ESI-MS Analysis of Pharmaceutical Compounds and their Metabolites   Christine L. Andrews, Eric T. Gangl, Meg Annan, Neil Spooner, Paul Vouros  Full Poster
  • The Analysis of Pharmaceutical Compounds by LC/MS/MS Utilizing a Nano-Splitting Device:  Investigation of Linearity and Dynamic Range Christine L. Andrews, Eric Yang, Chung-Ping Yu, Paul Vouros.   Full Poster
  • Drug Metabolism Studies Utilizing A Nanosplitting Device with On-line Mass Spectrometric and Radiomatic Detection Christine L. Andrews, Feng Li,  et al. Summary

Determination of metabolic pathways of vitamin D using GC-MS and LC-MS methods: 

  • C-25 Hydroxylation of the Antipsoriatic Drug  1α,24(R)-Dihydroxyvitamin D3 Is Catalyzed by 25-Hydroxyvitamin D3-24-Hydroxylase  (CYP24A1): Metabolism Studies with Human Keratinocytes and Recombinant CYP24A1,  Astecker, N., et al.  Archives Biochem. Biophys., 431, 261-270 (2004)
  • 1a,25-Dihydroxy-3-epi-Vitamin D3, a Natural Metabolite of 1a,25-Dihydroxy-Vitamin D3: Production and Biological Activity Studies in Pulmonary Alveoral Type II Cells  Rehan, V.K., et al.  Mol. Genet. Metab., 43, 3581-3586 (2002)
  • Isolation and identification of 1alpha-hydroxy-3-epi-vitamin D3, a potent suppressor of parathyroid hormone secretion.  Brown AJ, et al. J. Cell Biochem. 2005 Oct 15;96(3):569-78.