2024
Direct analysis in real time mass spectrometry (DART-MS/MS) for rapid urine opioid detection in a clinical setting
Choucair I, Shang E, Tran M, Cassella-McLane G, El-Khoury J. Direct analysis in real time mass spectrometry (DART-MS/MS) for rapid urine opioid detection in a clinical setting. Clinica Chimica Acta 2024, 564: 119939. PMID: 39197698, DOI: 10.1016/j.cca.2024.119939.Peer-Reviewed Original ResearchDART-MS/MSMass spectrometryReal time mass spectrometryTime mass spectrometrySample preparationLC-MS/MSEfficient sample preparationTandem mass spectrometryDirect analysisLiquid chromatography-tandem mass spectrometryChromatography-tandem mass spectrometryAnalytical measurement rangeVortex timeSpectrometryOpioid drugsTurnaround timeUrine samplesOpioidClinical settingDrug testingUrineDefinitive testsNorfentanylDrugPreparation
2022
A preliminary study of hydrocodone and hydromorphone to oxycodone ratios for distinguishing impurities from independent opioid use
Choucair I, Villalba C, Vera M, Cassella-Mclane G, Durant T, El-Khoury J. A preliminary study of hydrocodone and hydromorphone to oxycodone ratios for distinguishing impurities from independent opioid use. Clinical Biochemistry 2022, 112: 6-10. PMID: 36535386, DOI: 10.1016/j.clinbiochem.2022.12.009.Peer-Reviewed Original ResearchConceptsConcentrations of hydrocodoneMean ratioOxycodone pillsPrescription complianceOpioid useUDT resultsMedication recordsOxycodoneAdditional opiatesPatientsHydromorphoneLarger sample sizeAbstractTextHydrocodoneDrug abuseLiquid chromatography-tandem mass spectrometryDrug testingChromatography-tandem mass spectrometryLC-MS/MSFurther validationPreliminary studySample sizeOpiatesSensitive methodPills
2020
Investigating Interference with Lamotrigine Quantification by Liquid Chromatography–Tandem Mass Spectrometry
Hultgren C, Rogers K, Bunch DR, El-Khoury JM. Investigating Interference with Lamotrigine Quantification by Liquid Chromatography–Tandem Mass Spectrometry. The Journal Of Applied Laboratory Medicine 2020, 5: 609-611. PMID: 32445366, DOI: 10.1093/jalm/jfaa007.Peer-Reviewed Original Research
2011
A simple and fast liquid chromatography–tandem mass spectrometry method for measurement of underivatized l-arginine, symmetric dimethylarginine, and asymmetric dimethylarginine and establishment of the reference ranges
El-Khoury JM, Bunch DR, Reineks E, Jackson R, Steinle R, Wang S. A simple and fast liquid chromatography–tandem mass spectrometry method for measurement of underivatized l-arginine, symmetric dimethylarginine, and asymmetric dimethylarginine and establishment of the reference ranges. Analytical And Bioanalytical Chemistry 2011, 402: 771-779. PMID: 22124751, DOI: 10.1007/s00216-011-5462-9.Peer-Reviewed Original ResearchConceptsFast liquid chromatography–tandem mass spectrometry methodAnalytical cycle timeChromatography-tandem mass spectrometry methodLiquid chromatography-tandem mass spectrometry methodMinimum sample preparationMass spectrometry methodLiquid chromatography-tandem mass spectrometryChromatography-tandem mass spectrometryAsymmetric dimethylarginineSymmetric dimethylarginineLC-MS/MS methodMass spectrometerFormic acidSpectrometry methodMass spectrometrySilica columnProtein precipitationSample preparationInternal standardAmmonium acetateMS methodGlomerular filtration rateAnalytesNitric oxide synthaseΜM