Publications by authors named "Nikolai Stephanson"

Opiates comprise a class of abused drugs that is of primary interest in clinical and forensic urine drug testing. Determination of heroin, codeine, or a multi-drug ingestion is complicated since both heroin and codeine can lead to urinary excretion of free and conjugated morphine. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) offers advantage over gas chromatography-mass spectrometry by simplifying sample preparation but increases the number of analytes.

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Human interest in psychoactive phenethylamines is known from the use of mescaline-containing cacti and designer drugs such as Ecstasy. From the alkaloid composition of cacti we hypothesized that substances resembling Ecstasy might occur naturally. In this article we show that lophophine, homopiperonylamine and lobivine are new minor constituents of two cactus species, Lophophora williamsii (peyote) and Trichocereus pachanoi (San Pedro).

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A direct liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method for measurement of urinary Delta(9)-tetrahydrocannabinol carboxylic acid (THCA) was developed. The method involved dilution of the urine sample with water containing (2)H(9)-deuterated analogue as internal standard, hydrolysis with ammonia, reversed phase chromatography using a Waters ultra-performance liquid chromatography (UPLC) equipment with gradient elution, negative electrospray ionization, and monitoring of two product ions in selected reaction monitoring mode. The measuring range was 2-1000 ng/mL for THCA, and the intra- and inter-assay imprecision, expressed as the coefficient of variation, was below 5%.

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Ethyl glucuronide (EtG) is a direct metabolite of ethanol and has been used as a marker of alcohol abuse in both urine and hair. This study investigated the value of EtG testing in post-mortem hair for diagnostic improvement of alcohol abuse in forensic medicine. Material from 70 consecutive medico-legal autopsies was collected in accordance with the recommendations on ethics by the Swedish National Board of Forensic Medicine.

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A direct ultra-performance liquid chromatography-tandem mass spectrometry method (UPLC-MS/MS) for simultaneous measurement of urinary 5-hydroxytryptophol glucuronide (GTOL) and 5-hydroxyindoleacetic acid (5-HIAA) was developed. The GTOL/5-HIAA ratio is used as an alcohol biomarker with clinical and forensic applications. The method involved dilution of the urine sample with deuterated analogues (internal standards), reversed-phase chromatography with gradient elution, electrospray ionisation and monitoring of two product ions per analyte in selected reaction monitoring mode.

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Aims: This study compared two new methods for direct determination of 5-hydroxytryptophol glucuronide (GTOL) in urine, a biomarker for detection of recent alcohol consumption.

Methods: Urine samples were collected from ten alcoholic patients during recovery from intoxication. A direct injection ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for measurement of the urinary GTOL to 5-hydroxyindoleacetic acid (5-HIAA) ratio, and an ELISA assay for direct measurement of GTOL, were used.

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5-Hydroxytryptophol glucuronide (GTOL) is the major excretion form of 5-hydroxytryptophol (5-HTOL), a minor serotonin metabolite under normal conditions. Because the concentration of 5-HTOL is markedly increased following consumption of alcohol, measurement of 5-HTOL is used as a sensitive biomarker for detection of recent alcohol intake. This study describes the development and evaluation of a liquid chromatography-electrospray ionization mass spectrometry (LC-MS) procedure for direct quantification of GTOL in human urine.

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Ethyl glucuronide is a minor metabolite of ethanol, and its presence in urine can be used as a laboratory test to detect recent alcohol intake, even for some time after the ethanol is no longer measurable. A simple analytical procedure was developed based on direct injection of urine diluted with a deuterated internal standard into an electrospray liquid chromatographic-mass spectrometric (LC-MS) system. A novel LC system using a porous graphite column (Hypercarb) enabled an isocratic elution with retention times of 5-6 minutes.

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This study compared the urinary excretion characteristics of ethyl glucuronide (EtG) with that of ethanol, with focus on the effect of water-induced diuresis. Six healthy volunteers ingested an ethanol dose of 0.5 g/kg (range 25.

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