| Rapid method for accurate analysis of melatonin, serotonin and auxin in plant samples using liquid chromatography–tandem mass spectrometry J Cao, SJ Murch, R O’Brien, PK Saxena Journal of Chromatography A 1134 (1-2), 333-337, 2006 | 134 | 2006 |
| The mode of action of thidiazuron: auxins, indoleamines, and ion channels in the regeneration of Echinacea purpurea L. MPA Jones, J Cao, R O’Brien, SJ Murch, PK Saxena Plant Cell Reports 26, 1481-1490, 2007 | 115 | 2007 |
| Are clusters important in understanding the mechanisms in atmospheric pressure ionization? Part 1: Reagent ion generation and chemical control of ion populations S Klee, V Derpmann, W Wißdorf, S Klopotowski, H Kersten, ... Journal of the American Society for Mass Spectrometry 25, 1310-1321, 2014 | 53 | 2014 |
| A novel APPI-MS setup for in situ degradation product studies of atmospherically relevant compounds: capillary atmospheric pressure photo ionization (cAPPI) H Kersten, V Derpmann, I Barnes, KJ Brockmann, R O’brien, T Benter Journal of the American Society for Mass Spectrometry 22, 2070-2081, 2011 | 42 | 2011 |
| Evidence of neutral radical induced analyte ion transformations in APPI and near-VUV APLI H Kersten, V Funcke, M Lorenz, KJ Brockmann, T Benter, R O’brien Journal of the American Society for Mass Spectrometry 20, 1868-1880, 2009 | 31 | 2009 |
| Quantitation of select terpenes/terpenoids and nicotine using gas chromatography–mass spectrometry with high-temperature headspace sampling TD Nguyen, S Riordan-Short, TTT Dang, R O’Brien, M Noestheden ACS omega 5 (10), 5565-5573, 2020 | 29 | 2020 |
| Carbon disulfide as a dopant in photon‐induced chemical ionization mass spectrometry F Dousty, RT O'Brien, R Gahler, H Kersten, T Benter Rapid Communications in Mass Spectrometry 27 (17), 1969-1976, 2013 | 16 | 2013 |
| Comprehensive analytical chemistry JW Favell, R Hayward, E O’Brien, S Riordan‐Short, N Sagar, R O’Brien, ... Elsevier BV, Netherlands, Amsterdam, 2020 | 10 | 2020 |
| The use of isoprene as a novel dopant in negative ion atmospheric pressure photoionization mass spectrometry coupled to high‐performance liquid chromatography F Dousty, R O'Brien Rapid Communications in Mass Spectrometry 29 (11), 1031-1038, 2015 | 7 | 2015 |
| Quantitating cannabinoids in edible chocolates using heated ultrasonic-assisted extraction JW Favell, R Hayward, E O'Brien, S Riordan-Short, N Sagar, R O'Brien, ... Comprehensive Analytical Chemistry 90, 397-414, 2020 | 3 | 2020 |
| VUV Photoionization within Transfer Capillaries of Atmospheric Pressure Ionization Sources H Kersten, W Wissdorf, KJ Brockmann, T Benter, R OBrien Proceedings of the 58th ASMS Conference on Mass Spectrometry and Allied …, 2010 | 3 | 2010 |
| Progress in VUV measurements of a spark discharge lamp used for capillary Atmospheric Pressure Photoionization (cAPPI) H Kersten, M Dlugosch, K Kroll, KJ Brockmann, T Benter, R OBrien Proceedings of the 60th ASMS Conference on Mass Spectrometry and Allied Topics, 2012 | 1 | 2012 |
| Windowless Miniature Spark Discharge Light Sources for Efficient Generation of VUV Radiation Below 105 nm for On-Capillary APPI (CAPI) H Kersten, KJ Brockmann, R O’Brien, T Benter Windowless Miniature Spark Discharge Light Sources for Efficient Generation …, 2011 | 1 | 2011 |
| Role of non-ionizing photon absorption in the observed mass spectra produced by an Atmospheric Pressure Photoionization-LCMS source R O'Brien, A Furgeson, D Arkinstall 55 th ASMS Conference Proceedings, 2007 | 1 | 2007 |
| Quantitating terpenes/terpenoids and nicotine in plant materials and vaping products using high-temperature headspace gas chromatography–mass spectrometry TD Nguyen, S Riordan-Short, TTT Dang, R O'Brien, M Noestheden Comprehensive Analytical Chemistry 90, 139-168, 2020 | | 2020 |