| Drug screening of preserved oral fluid by liquid chromatography–tandem mass spectrometry EL Øiestad, U Johansen, AS Christophersen Clinical Chemistry 53 (2), 300-309, 2007 | 206 | 2007 |
| Simultaneous determination of 6 beta-blockers, 3 calcium-channel antagonists, 4 angiotensin-II antagonists and 1 antiarrhytmic drug in post-mortem whole blood by automated … L Kristoffersen, EL Øiestad, MS Opdal, M Krogh, E Lundanes, ... Journal of Chromatography B 850 (1-2), 147-160, 2007 | 182 | 2007 |
| Prevalence of alcohol and drugs among Norwegian motor vehicle drivers: a roadside survey H Gjerde, PT Normann, BS Pettersen, T Assum, M Aldrin, U Johansen, ... Accident Analysis & Prevention 40 (5), 1765-1772, 2008 | 150 | 2008 |
| Detection of drugs of abuse in simultaneously collected oral fluid, urine and blood from Norwegian drug drivers V Vindenes, HME Lund, W Andresen, H Gjerde, SE Ikdahl, ... Forensic science international 219 (1-3), 165-171, 2012 | 134 | 2012 |
| Drug screening of whole blood by ultra-performance liquid chromatography-tandem mass spectrometry EL Øiestad, U Johansen, ÅML Øiestad, AS Christophersen Journal of Analytical Toxicology 35 (5), 280-293, 2011 | 128 | 2011 |
| Comparison of drug concentrations between whole blood and oral fluid K Langel, H Gjerde, D Favretto, P Lillsunde, EL Øiestad, SD Ferrara, ... Drug testing and analysis 6 (5), 461-471, 2014 | 123 | 2014 |
| The PMMA epidemic in Norway: comparison of fatal and non-fatal intoxications M Vevelstad, EL Øiestad, G Middelkoop, I Hasvold, P Lilleng, ... Forensic science international 219 (1-3), 151-157, 2012 | 96 | 2012 |
| Electromembrane extraction of stimulating drugs from undiluted whole blood REG Jamt, A Gjelstad, LEE Eibak, EL Øiestad, AS Christophersen, ... Journal of Chromatography a 1232, 27-36, 2012 | 89 | 2012 |
| Oral fluid is a viable alternative for monitoring drug abuse: detection of drugs in oral fluid by liquid chromatography-tandem mass spectrometry and comparison to the results … V Vindenes, B Yttredal, EL Øiestad, H Waal, JP Bernard, JG Mørland, ... Journal of Analytical Toxicology 35 (1), 32-39, 2011 | 88 | 2011 |
| Prevalence of synthetic cannabinoids in blood samples from Norwegian drivers suspected of impaired driving during a seven weeks period SS Tuv, H Krabseth, R Karinen, KM Olsen, EL Øiestad, V Vindenes Accident Analysis & Prevention 62, 26-31, 2014 | 85 | 2014 |
| Levels of heroin and its metabolites in blood and brain extracellular fluid after iv heroin administration to freely moving rats A Gottås, EL Øiestad, F Boix, V Vindenes, Å Ripel, CH Thaulow, ... British journal of pharmacology 170 (3), 546-556, 2013 | 81 | 2013 |
| Electromembrane extraction using deep eutectic solvents as the liquid membrane FA Hansen, E Santigosa-Murillo, M Ramos-Payán, M Muñoz, EL Øiestad, ... Analytica chimica acta 1143, 109-116, 2021 | 76 | 2021 |
| Parallel electromembrane extraction in the 96-well format LEE Eibak, KE Rasmussen, EL Øiestad, S Pedersen-Bjergaard, ... Analytica chimica acta 828, 46-52, 2014 | 75 | 2014 |
| Bioanalysis of pharmaceuticals using liquid-phase microextraction combined with liquid chromatography–mass spectrometry F Hansen, EL Øiestad, S Pedersen-Bjergaard Journal of Pharmaceutical and Biomedical Analysis 189, 113446, 2020 | 73 | 2020 |
| Concentrations of APINACA, 5F-APINACA, UR-144 and its degradant product in blood samples from six impaired drivers compared to previous reported concentrations of other … R Karinen, SS Tuv, EL Øiestad, V Vindenes Forensic Science International 246, 98-103, 2015 | 70 | 2015 |
| Using biological samples in epidemiological research on drugs of abuse H Gjerde, EL Øiestad, AS Christophersen Norsk epidemiologi 21 (1), 2011 | 65 | 2011 |
| Determination of benzodiazepines in human urine using solid-phase extraction and high-performance liquid chromatography-electrospray ionization tandem mass spectrometry S Hegstad, EL Øiestad, U Johansen, AS Christophersen Journal of analytical toxicology 30 (1), 31-37, 2006 | 64 | 2006 |
| Underestimated impact of novel psychoactive substances: laboratory confirmation of recreational drug toxicity in Oslo, Norway OM Vallersnes, PS Persett, EL Øiestad, R Karinen, F Heyerdahl, ... Clinical toxicology 55 (7), 636-644, 2017 | 61 | 2017 |
| Drugs of abuse in oral fluid collected by two different sample kits–stability testing and validation using ultra performance tandem mass spectrometry analysis HME Lund, EL Øiestad, H Gjerde, AS Christophersen Journal of Chromatography B 879 (30), 3367-3377, 2011 | 58 | 2011 |
| Norwegian roadside survey of alcohol and drug use by drivers (2008–2009) H Gjerde, AS Christophersen, PT Normann, T Assum, EL Øiestad, ... Traffic injury prevention 14 (5), 443-452, 2013 | 51 | 2013 |
Trygve HelgakerUniversity of OsloVerified email at kjemi.uio.no
