Publications 2024

Fabris AL, Pedersen-Bjergaard S, Øiestad EL, Rossi GN, Hallak JEC, Dos Santos RG, Costa JL, Yonamine M (2024)
Solvent-free parallel artificial liquid membrane extraction for drugs of abuse in plasma samples using LC-MS/MS
Anal Chim Acta, 1301, 342387
DOI 10.1016/j.aca.2024.342387, PubMed 38553114

Publications 2023

Gjerde H, Oyono Y, Jamt REG, Tayimetha CY, Asongalem EA, Akum EA, Øiestad EL (2023)
Drug analysis: Comparison between dried plasma spots and liquid plasma samples of trauma patients from Cameroon-A feasibility study
Drug Test Anal, 16 (3), 303-308
DOI 10.1002/dta.3545, PubMed 37464568

Schüller M, Lucic I, Øiestad ÅML, Pedersen-Bjergaard S, Øiestad EL (2023)
High-throughput quantification of emerging "nitazene" benzimidazole opioid analogs by microextraction and UHPLC-MS-MS
J Anal Toxicol, 47 (9), 787-796
DOI 10.1093/jat/bkad071, PubMed 37700512

Skaalvik TG, Zhou C, Øiestad EL, Hegstad S, Trones R, Pedersen-Bjergaard S (2023)
Conductive vial electromembrane extraction of opioids from oral fluid
Anal Bioanal Chem, 415 (22), 5323-5335
DOI 10.1007/s00216-023-04807-3, PubMed 37386201

Skaalvik TG, Øiestad EL, Pedersen-Bjergaard S, Hegstad S (2023)
Determination of amphetamine enantiomers in urine by conductive vial electromembrane extraction and ultra-high performance supercritical fluid chromatography tandem mass spectrometry
Drug Test Anal, 15 (8), 909-918
DOI 10.1002/dta.3487, PubMed 37114617

Øiestad EL, Øiestad ÅML, Middelkoop G, Brochmann GW, Thaulow CH, Vindenes V (2023)
Comparative Study of Postmortem Concentrations of Benzodiazepines and Z-Hypnotics in Several Different Matrices
J Anal Toxicol, 47 (3), 287-298
DOI 10.1093/jat/bkac106, PubMed 36542823

Publications 2021

Mestad IO, Gjelstad A, Pedersen-Bjergaard S, Oiestad EL (2021)
Green and sustainable drug analysis-Combining microsampling and microextraction of drugs of abuse
SUSTAIN. CHEM. PHARM., 24, 100517
DOI 10.1016/j.scp.2021.100517

Oiestad EL, Bojko B, Boyaci E (2021)
Novel approaches and green sample preparation in bioanalytical protocols
SUSTAIN. CHEM. PHARM., 24, 100559
DOI 10.1016/j.scp.2021.100559

Pettersen S, Øiestad ÅML, Rogde S, Brochmann GW, Øiestad EL, Vindenes V (2021)
Distribution of tetrahydrocannabinol and cannabidiol in several different postmortem matrices
Forensic Sci Int, 329, 111082
DOI 10.1016/j.forsciint.2021.111082, PubMed 34775328

Schüller M, Tran KTT, Øiestad EL, Pedersen-Bjergaard S (2021)
Membrane-based liquid-phase microextraction of basic pharmaceuticals - A study on the optimal extraction window
J Chromatogr A, 1664, 462769
DOI 10.1016/j.chroma.2021.462769, PubMed 34998024

Skaalvik TG, Øiestad EL, Trones R, Pedersen-Bjergaard S, Hegstad S (2021)
Determination of psychoactive drugs in serum using conductive vial electromembrane extraction combined with UHPLC-MS/MS
J Chromatogr B Analyt Technol Biomed Life Sci, 1183, 122926
DOI 10.1016/j.jchromb.2021.122926, PubMed 34624684

Publications 2020

Bavlovič Piskáčková H, Øiestad EL, Váňová N, Lengvarská J, Štěrbová-Kovaříková P, Pedersen-Bjergaard S (2020)
Electromembrane extraction of anthracyclines from plasma: Comparison with conventional extraction techniques
Talanta, 223 (Pt 2), 121748
DOI 10.1016/j.talanta.2020.121748, PubMed 33298272

Drobnjak M, Hansen F, Øiestad EL, Løvli T, Trones R, Martinsen G, Pedersen-Bjertgaard S (2020)
Electromembrane Extraction with Vitals of Counducting Polymer
LCGCN North America, 38 (8), 435-439
PublikaID 355

Hansen F, Jaghl F, Leere Øiestad E, Jensen H, Pedersen-Bjergaard S, Huang C (2020)
Impact of ion balance in electromembrane extraction
Anal Chim Acta, 1124, 129-136
DOI 10.1016/j.aca.2020.05.039, PubMed 32534665

Hansen F, Øiestad EL, Pedersen-Bjergaard S (2020)
Bioanalysis of pharmaceuticals using liquid-phase microextraction combined with liquid chromatography-mass spectrometry
J Pharm Biomed Anal, 189, 113446
DOI 10.1016/j.jpba.2020.113446, PubMed 32619730

Hansen FA, Kubáň P, Øiestad EL, Pedersen-Bjergaard S (2020)
Electromembrane extraction of highly polar bases from biological samples - Deeper insight into bis(2-ethylhexyl) phosphate as ionic carrier
Anal Chim Acta, 1115, 23-32
DOI 10.1016/j.aca.2020.04.027, PubMed 32370866

Hansen FA, Santigosa-Murillo E, Ramos-Payán M, Muñoz M, Leere Øiestad E, Pedersen-Bjergaard S (2020)
Electromembrane extraction using deep eutectic solvents as the liquid membrane
Anal Chim Acta, 1143, 109-116
DOI 10.1016/j.aca.2020.11.044, PubMed 33384108

Seljetun KO, Sandvik M, Vindenes V, Eliassen E, Øiestad EL, Madslien K, Moe L (2020)
Comparison of anticoagulant rodenticide concentrations in liver and feces from apparently healthy red foxes
J Vet Diagn Invest, 32 (4), 560-564
DOI 10.1177/1040638720927365, PubMed 32476615

Seljetun KO, Vindenes V, Øiestad EL, Brochmann GW, Eliassen E, Moe L (2020)
Determination of anticoagulant rodenticides in faeces of exposed dogs and in a healthy dog population
Acta Vet Scand, 62 (1), 30
DOI 10.1186/s13028-020-00531-5, PubMed 32546243

Publications 2019

Ask KS, Lid M, Øiestad EL, Pedersen-Bjergaard S, Gjelstad A (2019)
Liquid-phase microextraction in 96-well plates - calibration and accurate quantification of pharmaceuticals in human plasma samples
J Chromatogr A, 1602, 117-123
DOI 10.1016/j.chroma.2019.06.013, PubMed 31229251

Bretteville-Jensen AL, Burdzovic Andreas J, Gjersing L, Øiestad EL, Gjerde H (2019)
Identification and Assessment of Drug-User Groups Among Nightlife Attendees: Self-Reports, Breathalyzer-Tests and Oral Fluid Drug Tests
Eur Addict Res, 25 (2), 93-102
DOI 10.1159/000497318, PubMed 30783038

Bruun LD, Kjeldstadli K, Temte V, Birdal M, Bachs L, Langødegård M, Strand DH, Gaare KI, Øiestad E, Høiseth G (2019)
Detection Time of Oxazepam and Zopiclone in Urine and Oral Fluid after Experimental Oral Dosing
J Anal Toxicol, 43 (5), 369-377
DOI 10.1093/jat/bky083, PubMed 30615130

Oiestad EL, Krabseth HM, Huestis MA, Skulberg A, Vindenes V (2019)
Interpreting oral fluid drug results in prisoners: monitoring current drug intake and detection times for drugs self-administered prior to detention
Forensic Toxicol., 37 (1), 59-74
DOI 10.1007/s11419-018-0434-9

Seljetun KO, Eliassen E, Madslien K, Viljugrein H, Vindenes V, Øiestad EL, Moe L (2019)
PREVALENCE OF ANTICOAGULANT RODENTICIDES IN FECES OF WILD RED FOXES (VULPES VULPES) IN NORWAY
J Wildl Dis, 55 (4), 834-843
DOI 10.7589/2019-01-027, PubMed 31112468

Temte V, Kjeldstadli K, Bruun LD, Birdal M, Bachs L, Karinen R, Middelkoop G, Øiestad E, Høiseth G (2019)
An Experimental Study of Diazepam and Alprazolam Kinetics in Urine and Oral Fluid Following Single Oral Doses
J Anal Toxicol, 43 (2), 104-111
DOI 10.1093/jat/bky062, PubMed 30517712

Vårdal L, Øiestad EL, Gjelstad A, Jensen H, Pedersen-Bjergaard S (2019)
Electromembrane extraction with solvent modification of the acceptor solution: improved mass transfer of drugs of abuse from human plasma
Bioanalysis, 11 (8), 755-771
DOI 10.4155/bio-2018-0308, PubMed 30994001

Publications 2018

Ask KS, Øiestad EL, Pedersen-Bjergaard S, Gjelstad A (2018)
Dried blood spots and parallel artificial liquid membrane extraction-A simple combination of microsampling and microextraction
Anal Chim Acta, 1009, 56-64
DOI 10.1016/j.aca.2018.01.024, PubMed 29422132

Kvello AMS, Andersen JM, Øiestad EL, Steinsland S, Aase A, Mørland J, Bogen IL (2018)
A Monoclonal Antibody against 6-Acetylmorphine Protects Female Mice Offspring from Adverse Behavioral Effects Induced by Prenatal Heroin Exposure
J Pharmacol Exp Ther, 368 (1), 106-115
DOI 10.1124/jpet.118.251504, PubMed 30361238

Oiestad AML, Berg T, Eliassen E, Wiklund T, Sand K, Oiestad EL (2018)
Separation of isomers of new psychoactive substances and isotope-labeled amphetamines using UHPSFC-MS/MS and UHPLC-MS/MS
J. Liq. Chromatogr. Relat. Technol., 41 (7), 391-400
DOI 10.1080/10826076.2017.1388818

Thaulow CH, Øiestad ÅML, Rogde S, Karinen R, Brochmann GW, Andersen JM, Høiseth G, Handal M, Mørland J, Arnestad M, Øiestad EL, Strand DH, Vindenes V (2018)
Metabolites of Heroin in Several Different Post-mortem Matrices
J Anal Toxicol, 42 (5), 311-320
DOI 10.1093/jat/bky002, PubMed 29409037

Vårdal L, Wong G, Øiestad ÅML, Pedersen-Bjergaard S, Gjelstad A, Øiestad EL (2018)
Rapid determination of designer benzodiazepines, benzodiazepines, and Z-hypnotics in whole blood using parallel artificial liquid membrane extraction and UHPLC-MS/MS
Anal Bioanal Chem, 410 (20), 4967-4978
DOI 10.1007/s00216-018-1147-y, PubMed 29947895

Vårdal L, Øiestad EL, Gjelstad A, Pedersen-Bjergaard S (2018)
Electromembrane extraction of substances with weakly basic properties: a fundamental study with benzodiazepines
Bioanalysis, 10 (10), 769-781
DOI 10.4155/bio-2018-0030, PubMed 29771135

Øiestad ÅML, Karinen R, Rogde S, Nilsen S, Boye Eldor KB, Brochmann GW, Arnestad M, Øiestad EL, Peres MD, Kristoffersen L, Vindenes V (2018)
Comparative Study of Postmortem Concentrations of Antidepressants in Several Different Matrices
J Anal Toxicol, 42 (7), 446-458
DOI 10.1093/jat/bky030, PubMed 29762694

Publications 2017

Hjelmeland K, Gustavsen I, Øiestad EL, Øiestad ÅML, Høiseth G, Mørland J (2017)
Zopiclone concentrations in oral fluid and blood after, administration of therapeutic doses of zopiclone
Forensic Sci Int, 278, 177-183
DOI 10.1016/j.forsciint.2017.07.004, PubMed 28735217

Vallersnes OM, Persett PS, Øiestad EL, Karinen R, Heyerdahl F, Hovda KE (2017)
Underestimated impact of novel psychoactive substances: laboratory confirmation of recreational drug toxicity in Oslo, Norway
Clin Toxicol (Phila), 55 (7), 636-644
DOI 10.1080/15563650.2017.1312002, PubMed 28406320

Vevelstad M, Øiestad EL, Nerem E, Arnestad M, Bogen IL (2017)
Studies on Para-Methoxymethamphetamine (PMMA) Metabolite Pattern and Influence of CYP2D6 Genetics in Human Liver Microsomes and Authentic Samples from Fatal PMMA Intoxications
Drug Metab Dispos, 45 (12), 1326-1335
DOI 10.1124/dmd.117.077263, PubMed 28978661

Vårdal L, Askildsen HM, Gjelstad A, Øiestad EL, Edvardsen HM, Pedersen-Bjergaard S (2017)
Parallel artificial liquid membrane extraction of new psychoactive substances in plasma and whole blood
J Chromatogr B Analyt Technol Biomed Life Sci, 1048, 77-84
DOI 10.1016/j.jchromb.2017.02.010, PubMed 28226266

Vårdal L, Gjelstad A, Huang C, Øiestad EL, Pedersen-Bjergaard S (2017)
Efficient discrimination and removal of phospholipids during electromembrane extraction from human plasma samples
Bioanalysis, 9 (8), 631-641
DOI 10.4155/bio-2017-0027, PubMed 28508669

Øiestad EL, Karinen RA, Haugland K, Øiestad ML (2017)
Chapter 101 Screening of Synthetic Cannabinoids
In Handbook of Cannabis and Related Pathologies (Victor R. Preedy, ed.), Academic Press, San Diego, 1, 981-997
DOI 10.1016/B978-0-12-800756-3.00118-6, PublikaID 291, ISBN 978-0-12-800756-3

Publications 2016

Andås HT, Enger A, Øiestad ÅM, Vindenes V, Christophersen AS, Huestis MA, Øiestad EL (2016)
Extended Detection of Amphetamine and Methamphetamine in Oral Fluid
Ther Drug Monit, 38 (1), 114-9
DOI 10.1097/FTD.0000000000000248, PubMed 26402425

Ask KS, Bardakci T, Parmer MP, Halvorsen TG, Øiestad EL, Pedersen-Bjergaard S, Gjelstad A (2016)
Parallel artificial liquid membrane extraction as an efficient tool for removal of phospholipids from human plasma
J Pharm Biomed Anal, 129, 229-236
DOI 10.1016/j.jpba.2016.07.011, PubMed 27433988

Krabseth HM, Tuv SS, Strand MC, Karinen RA, Wiik E, Vevelstad MS, Westin AA, Oiestad EL, Vindenes V (2016)
New psychoactive substances
Tidsskr. Nor. Laegeforen., 136 (8), 714-717

Krabseth HM, Tuv SS, Strand MC, Karinen RA, Wiik E, Vevelstad MS, Westin AA, Øiestad EL, Vindenes V (2016)
Novel psychoactive substances
Tidsskr Nor Laegeforen, 136 (8), 714-7
DOI 10.4045/tidsskr.15.1278, PubMed 27143461

Kvello AM, Andersen JM, Øiestad EL, Mørland J, Bogen IL (2016)
Pharmacological Effects of a Monoclonal Antibody against 6-Monoacetylmorphine upon Heroin-Induced Locomotor Activity and Pharmacokinetics in Mice
J Pharmacol Exp Ther, 358 (2), 181-9
DOI 10.1124/jpet.116.233510, PubMed 27217591

Tuv SS, Krabseth HM, Strand MC, Karinen RA, Wiik E, Vevelstad MS, Westin AA, Oiestad EL, Vindenes V (2016)
New drugs right from the online
Tidsskr. Nor. Laegeforen., 136 (8), 721-723

Tuv SS, Krabseth HM, Strand MC, Karinen RA, Wiik E, Vevelstad MS, Westin AA, Øiestad EL, Vindenes V (2016)
New designer drugs from the web
Tidsskr Nor Laegeforen, 136 (8), 721-3
DOI 10.4045/tidsskr.15.1276, PubMed 27143463

Vevelstad M, Øiestad EL, Bremer S, Bogen IL, Zackrisson AL, Arnestad M (2016)
Is toxicity of PMMA (paramethoxymethamphetamine) associated with cytochrome P450 pharmacogenetics?
Forensic Sci Int, 261, 137-47
DOI 10.1016/j.forsciint.2016.02.027, PubMed 26930544

Øiestad EL, Øiestad ÅM, Gjelstad A, Karinen R (2016)
Oral fluid drug analysis in the age of new psychoactive substances
Bioanalysis, 8 (7), 691-710
DOI 10.4155/bio-2015-0027, PubMed 26964619

Publications 2015

Gjerde H, Nordfjærn T, Bretteville-Jensen AL, Edland-Gryt M, Furuhaugen H, Karinen R, Øiestad EL (2015)
Comparison of drugs used by nightclub patrons and criminal offenders in Oslo, Norway
Forensic Sci Int, 265, 1-5
DOI 10.1016/j.forsciint.2015.12.029, PubMed 26826845

Gottås A, Ripel Å, Boix F, Vindenes V, Mørland J, Øiestad EL (2015)
Determination of dopamine concentrations in brain extracellular fluid using microdialysis with short sampling intervals, analyzed by ultra high performance liquid chromatography tandem mass spectrometry
J Pharmacol Toxicol Methods, 74, 75-9
DOI 10.1016/j.vascn.2015.06.002, PubMed 26123500

Nordal K, Øiestad EL, Enger A, Christophersen AS, Vindenes V (2015)
Detection Times of Diazepam, Clonazepam, and Alprazolam in Oral Fluid Collected From Patients Admitted to Detoxification, After High and Repeated Drug Intake
Ther Drug Monit, 37 (4), 451-60
DOI 10.1097/FTD.0000000000000174, PubMed 25549207

Publications 2014

Andås HT, Krabseth HM, Enger A, Marcussen BN, Haneborg AM, Christophersen AS, Vindenes V, Øiestad EL (2014)
Detection time for THC in oral fluid after frequent cannabis smoking
Ther Drug Monit, 36 (6), 808-14
DOI 10.1097/FTD.0000000000000092, PubMed 24819969

Edvardsen HM, Karinen R, Moan IS, Oiestad EL, Christophersen AS, Gjerde H (2014)
Use of alcohol and drugs among health professionals in Norway: a study using data from questionnaires and samples of oral fluid
J Occup Med Toxicol, 9 (1), 8
DOI 10.1186/1745-6673-9-8, PubMed 24612541

Eibak LE, Rasmussen KE, Oiestad EL, Pedersen-Bjergaard S, Gjelstad A (2014)
Parallel electromembrane extraction in the 96-well format
Anal Chim Acta, 828, 46-52
DOI 10.1016/j.aca.2014.04.038, PubMed 24845814

Gjerde H, Sousa TR, De Boni R, Christophersen AS, Limberger RP, Zancanaro I, Oiestad EL, Normann PT, Mørland J, Pechansky F (2014)
A comparison of alcohol and drug use by random motor vehicle drivers in Brazil and Norway
Int J Drug Policy, 25 (3), 393-400
DOI 10.1016/j.drugpo.2014.01.019, PubMed 24613265

Gottås A, Boix F, Øiestad EL, Vindenes V, Mørland J (2014)
Role of 6-monoacetylmorphine in the acute release of striatal dopamine induced by intravenous heroin
Int J Neuropsychopharmacol, 17 (9), 1357-65
DOI 10.1017/S1461145714000169, PubMed 24576415

Karinen R, Tuv SS, Øiestad EL, Vindenes V (2014)
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 synthetic cannabinoids
Forensic Sci Int, 246, 98-103
DOI 10.1016/j.forsciint.2014.11.012, PubMed 25485949

Karinen R, Vindenes V, Hasvold I, Olsen KM, Christophersen AS, Øiestad E (2014)
Determination of a selection of anti-epileptic drugs and two active metabolites in whole blood by reversed phase UPLC-MS/MS and some examples of application of the method in forensic toxicology cases
Drug Test Anal, 7 (7), 634-44
DOI 10.1002/dta.1733, PubMed 25331692

Vindenes V, Enger A, Nordal K, Johansen U, Christophersen AS, Oiestad EL (2014)
Very long Detection Times after High and repeated intake of Heroin and Methadone, measured in Oral Fluid
Scand. J. Forensic Sci., 20 (2), 34-41
DOI 10.2478/sjfs-2014-0004

Vindenes V, Enger A, Nordal K, Johansen U, Cristophersen AS, Øiestad EL (2014)
Very long Detection Times after High and repeated intake of Heroin and Methadone, measured in Oral Fluid
Scandinavian Journal of Forensic Science, 20 (2), 34-41
DOI 10.2478/sjfs-2014-0004, PublikaID 292

Publications 2013

Gjerde H, Christophersen AS, Normann PT, Assum T, Oiestad EL, Mørland J (2013)
Norwegian roadside survey of alcohol and drug use by drivers (2008-2009)
Traffic Inj Prev, 14 (5), 443-52
DOI 10.1080/15389588.2012.728016, PubMed 23697895

Gottås A, Øiestad EL, Boix F, Vindenes V, Ripel Å, Thaulow CH, Mørland J (2013)
Levels of heroin and its metabolites in blood and brain extracellular fluid after i.v. heroin administration to freely moving rats
Br J Pharmacol, 170 (3), 546-56
DOI 10.1111/bph.12305, PubMed 23865556

Langel K, Gjerde H, Favretto D, Lillsunde P, Øiestad EL, Ferrara SD, Verstraete AG (2013)
Comparison of drug concentrations between whole blood and oral fluid
Drug Test Anal, 6 (5), 461-71
DOI 10.1002/dta.1532, PubMed 24039237

Lund HM, Gjerde H, de Courtade SM, Oiestad EL, Christophersen AS (2013)
A Norwegian study of the suitability of hair samples in epidemiological research of alcohol, nicotine and drug use
J Anal Toxicol, 37 (6), 362-8
DOI 10.1093/jat/bkt038, PubMed 23689070

Lund HME, Gjerde H, DeCourtade SM, Øiestad EL, Christophersen AS (2013)
A Norwegian study of the suitability of hair samples in epidemiological research of alcohol, nicotine and drug use
J Anal Toxicol, 37 (6), 362-8
DOI 10.1093/jat/bkt038 , PublikaID 266

Oiestad EL, Johansen U, Christophersen AS, Karinen R (2013)
Screening of synthetic cannabinoids in preserved oral fluid by UPLC-MS/MS
Bioanalysis, 5 (18), 2257-68
DOI 10.4155/bio.13.182, PubMed 24053241

Tuv SS, Krabseth H, Karinen R, Olsen KM, Øiestad EL, Vindenes V (2013)
Prevalence of synthetic cannabinoids in blood samples from Norwegian drivers suspected of impaired driving during a seven weeks period
Accid Anal Prev, 62, 26-31
DOI 10.1016/j.aap.2013.09.009, PubMed 24129318

Øiestad EL, Karinen R, Christophersen AS, Vindenes V, Bachs L (2013)
Analyses of beverage remains in drug rape cases revealing drug residues--the possibility of contamination from drug concentrated oral fluid or oral cavity contained tablets
J Forensic Sci, 59 (1), 208-10
DOI 10.1111/1556-4029.12270, PubMed 24117495

Publications 2012

Gottas A, Oiestad EL, Boix F, Ripel A, Thaulow CH, Pettersen BS, Vindenes V, Morland J (2012)
Simultaneous measurement of heroin and its metabolites in brain extracellular fluid by microdialysis and ultra performance liquid chromatography tandem mass spectrometry
J Pharmacol Toxicol Methods, 66 (1), 14-21
DOI 10.1016/j.vascn.2012.04.009, PubMed 22561414

Storhaug LW, Enger A, Hjelmeland K, Øiestad EL, Vindenes V (2012)
Prolonged excretion of 7-aminoclonazepam in urine after repeated ingestion of clonazepam: a case report
Forensic Sci Int, 222 (1-3), e33-5
DOI 10.1016/j.forsciint.2012.06.018, PubMed 22819278

Tuv SS, Strand MC, Karinen R, Øiestad EL, Christophersen AS, Vindenes V (2012)
[Effect and occurrence of synthetic cannabinoids]
Tidsskr Nor Laegeforen, 132 (20), 2285-8
DOI 10.4045/tidsskr.12.0471, PubMed 23736196

Vevelstad M, Øiestad EL, Middelkoop G, Hasvold I, Lilleng P, Delaveris GJ, Eggen T, Mørland J, Arnestad M (2012)
The PMMA epidemic in Norway: comparison of fatal and non-fatal intoxications
Forensic Sci Int, 219 (1-3), 151-7
DOI 10.1016/j.forsciint.2011.12.014, PubMed 22257968

Vindenes V, Lund HM, Andresen W, Gjerde H, Ikdahl SE, Christophersen AS, Øiestad EL (2012)
Detection of drugs of abuse in simultaneously collected oral fluid, urine and blood from Norwegian drug drivers
Forensic Sci Int, 219 (1-3), 165-71
DOI 10.1016/j.forsciint.2012.01.001, PubMed 22284072

Vindenes V, Lund HME, Andresen W, Gjerde H, Ikdahl SE, Christophersen AS, Øiestad EL (2012)
Detection of drugs of abuse in simultaneously collected oral fluid, urine and blood from Norwegian drug drivers
Forensic Sci Int, 219 (1-3), 165
PublikaID 265

Publications 2011

Gjerde H, Øiestad EL, Christophersen AS (2011)
Using biological samples in epidemiological research on drugs of abuse
Norsk Epidemiologi, 21 (1), 5-14
PublikaID 293

Jamt RE, Gjelstad A, Eibak LE, Øiestad EL, Christophersen AS, Rasmussen KE, Pedersen-Bjergaard S (2011)
Electromembrane extraction of stimulating drugs from undiluted whole blood
J Chromatogr A, 1232, 27-36
DOI 10.1016/j.chroma.2011.08.058, PubMed 21899849

Karinen R, Øiestad EL, Andresen W, Smith-Kielland A, Christophersen A (2011)
Comparison of the stability of stock solutions of drugs of abuse and other drugs stored in a freezer, refrigerator, and at ambient temperature for up to one year
J Anal Toxicol, 35 (8), 583-90
DOI 10.1093/anatox/35.8.583, PubMed 22004679

Lund HM, Øiestad EL, Gjerde H, Christophersen AS (2011)
Drugs of abuse in oral fluid collected by two different sample kits--stability testing and validation using ultra performance tandem mass spectrometry analysis
J Chromatogr B Analyt Technol Biomed Life Sci, 879 (30), 3367-77
DOI 10.1016/j.jchromb.2011.09.002, PubMed 21962269

Lund HME, Øiestad EL, Gjerde H, Christophersen AS (2011)
Drugs of abuse in oral fluid collected by two different sample kits-stability testing and validation using ultra performance tandem mass spectrometry analysis.
J Chromatogr B Analyt Technol Biomed Life Sci, 879 (30), 3367-77
DOI 10.1016/j.jchromb.2011.09.002 , PublikaID 263

Oiestad EL, Johansen U, Oiestad AM, Christophersen AS (2011)
Drug screening of whole blood by ultra-performance liquid chromatography-tandem mass spectrometry
J Anal Toxicol, 35 (5), 280-93
DOI 10.1093/anatox/35.5.280, PubMed 21619723

Vindenes V, Yttredal B, Oiestad EL, Waal H, Bernard JP, Mørland JG, Christophersen AS (2011)
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 from urine samples from patients treated with Methadone or Buprenorphine
J Anal Toxicol, 35 (1), 32-9
DOI 10.1093/anatox/35.1.32, PubMed 21219701

Publications 2010

Gjerde H, Øiestad EL, Øiestad ÅM, Langødegård M, Gustavsen I, Hjelmeland K, Bernard JP, Christophersen AS (2010)
Comparison of zopiclone concentrations in oral fluid sampled with Intercept(®) oral specimen collection device and Statsure Saliva Sampler™ and concentrations in blood
J Anal Toxicol, 34 (9), 590-3
DOI 10.1093/jat/34.9.590, PubMed 21073813

Karinen R, Oiestad EL, Andresen W, Wethe G, Smith-Kielland A, Christophersen A (2010)
Comparison of ethanol and other drugs of abuse concentrations in whole blood stored in venoject glass and plastic and venosafe plastic evacuated tubes
J Anal Toxicol, 34 (7), 420-8
DOI 10.1093/jat/34.7.420, PubMed 20822681

Publications 2009

Oiestad EL, Johansen U, Stokke Opdal M, Bergan S, Christophersen AS (2009)
Determination of digoxin and digitoxin in whole blood
J Anal Toxicol, 33 (7), 372-8
DOI 10.1093/jat/33.7.372, PubMed 19796507

Publications 2008

Gjerde H, Normann PT, Pettersen BS, Assum T, Aldrin M, Johansen U, Kristoffersen L, Øiestad EL, Christophersen AS, Mørland J (2008)
Prevalence of alcohol and drugs among Norwegian motor vehicle drivers: a roadside survey
Accid Anal Prev, 40 (5), 1765-72
DOI 10.1016/j.aap.2008.06.015, PubMed 18760106

Publications 2007

Hegstad S, Khiabani HZ, Øiestad EL, Berg T, Christophersen AS (2007)
Rapid quantification of buprenorphine-glucuronide and norbuprenorphine-glucuronide in human urine by LC-MS-MS
J Anal Toxicol, 31 (4), 214-9
DOI 10.1093/jat/31.4.214, PubMed 17555645

Publications 2006

Hegstad S, Øiestad EL, Johansen U, Christophersen AS (2006)
Determination of benzodiazepines in human urine using solid-phase extraction and high-performance liquid chromatography-electrospray ionization tandem mass spectrometry
J Anal Toxicol, 30 (1), 31-7
DOI 10.1093/jat/30.1.31, PubMed 16620529

Kristoffersen L, Øiestad EL, Opdal MS, Krogh M, Lundanes E, Christophersen AS (2006)
Simultaneous determination of 6 beta-blockers, 3 calcium-channel antagonists, 4 angiotensin-II antagonists and 1 antiarrhythmic drug in post-mortem whole blood by automated solid phase extraction and liquid chromatography mass spectrometry. Method development and robustness testing by experimental design
J Chromatogr B Analyt Technol Biomed Life Sci, 850 (1-2), 147-60
DOI 10.1016/j.jchromb.2006.11.030, PubMed 17175206

Øiestad EL, Johansen U, Christophersen AS (2006)
Drug screening of preserved oral fluid by liquid chromatography-tandem mass spectrometry
Clin Chem, 53 (2), 300-9
DOI 10.1373/clinchem.2006.074237, PubMed 17158196

Publications 2000

Øiestad EL, Harvey JN, Uggerud E (2000)
Unimolecular reactions of protonated hydrogen peroxide: A quantum chemical survey
Journal of Physical Chemistry A, 104, 8382-8388
DOI 10.1021/jp000480g, PublikaID 369

Øiestad EL, Uggerud E (2000)
Dipolar H-2 activation by H2O
Chemical Communications, 1 (10), 831-832
DOI 10.1039/b001209m, PublikaID 370

Øiestad EL, Uggerud E (2000)
Competition between proton transfer and hydride abstraction in chemical ionisation mass spectrometry of ethylamine
International Journal of Mass Spectrometry, 199 (1-3), 91-105
PublikaID 371

Publications 1999

Øiestad EL, Uggerud E (1999)
The unimolecular chemistry of protonated hydroxylamine
International Journal of Mass Spectrometry, 185, 231-240
PublikaID 368

Publications 1997

Øiestad EL, Uggerud E (1997)
Unimolecular reactions of protonated hydrazine. Reaction mechanisms and dynamics from observation of metastable ion fragmentations and ab initio calculations
International Journal of Mass Spectrometry, 165, 39-47
PublikaID 367

Publications 1995

Øiestad EL, Øiestad ML, Skaane H, Ruud K, Helgaker T, Uggerud E (1995)
Loss of H-2 from CH3NH3+, CH3OH2+ and CH3FH+ - Reaction-Mechanisms and Dynamics from Observation of Metastable Ion Fragmentations and Ab-Initio Calculations Reaction-Mechanisms
Europeamn Mass Spectrometry, 1 (2), 121-129
PublikaID 366