Wolfgang Weinmann

Bio: Wolfgang Weinmann is an academic researcher from University of Bern. The author has contributed to research in topics: Ethyl glucuronide & Phosphatidylethanol. The author has an hindex of 51, co-authored 188 publications receiving 7484 citations. Previous affiliations of Wolfgang Weinmann include University of Freiburg & University Medical Center Freiburg.

Development of a multi-target screening analysis for 301 drugs using a QTrap liquid chromatography/tandem mass spectrometry system and automated library searching.

Abstract: A new multi-target screening (MTS) procedure for drugs in blood and urine for toxicological analysis has been developed using a hybrid triple-quadrupole linear ion trap mass spectrometer (QTrap) for the fast detection and identification of 301 forensically important drugs, e.g. tranquilizers (benzodiazepines), hypnotics, drugs of abuse (opiates, cocaine, amphetamines, cannabinoids), antidepressants, neuroleptics, and some cardiac drugs, in one single liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis. Samples were extracted either with liquid-liquid extraction or solid-phase extraction. A multiple reaction monitoring (MRM) as survey scan and an enhanced product ion (EPI) scan as dependent scan were performed in an information-dependent acquisition (IDA) experiment. Finally, drug identification was carried out by library search with a newly developed MS/MS library based on EPI spectra at three different collision energies in positive mode. The advantage of this newly developed method is the possibility to detect and identify 301 drugs in one single LC/MS/MS run.

Ethyl glucuronide—the direct ethanol metabolite on the threshold from science to routine use

Abstract: Aims Current biological state markers remain suboptimal with regard to sensitivity and specificity for monitoring recent alcohol consumption in various settings. Furthermore, these biomarkers can be influenced by age, gender and a variety of substances and non-alcohol-associated diseases and do not cover fully the time axis for alcohol intake. Ethyl glucuronide (EtG) is a non-volatile, watersoluble, stable, direct metabolite of ethanol that can be detected in various body fluids, tissues and hair. Shortly after the consumption even of small amounts of ethanol, EtG becomes positive. It can detect ethanol intake up to 80 hours after the complete elimination of alcohol from the body, covering a unique and important time spectrum for recent alcohol use. EtG seems to meet the need for a sensitive and specific marker to elucidate alcohol use not detected by standard testing. Design, setting, participants, methods and findings The literature was reviewed with a focus on possible diagnostic and therapeutic applications, currently available methods and future perspectives. To date, more than 4000 samples of body fluids, tissues and hair from approximately 1500 individuals have been assessed. Conclusions The data suggest that EtG is a useful tool in numerous settings, including alcohol and drug treatment (to detect lapse/relapse and for motivational feedback), in safety sensitive work settings where use is dangerous or in other settings where alcohol use may be risky (e.g. such as driving, work-place, pregnancy or monitoring physicians or other professionals who are in recovery and working) or for resolving forensic questions. If the question of recent alcohol consumption has to be answered in a binary way (yes/no), such as for determining lapses, the use of EtG in urine is among the preferred tests. The use of this marker alone and complementary with other biological state markers and self-reports is expected to lead to significant improvement in treatment outcome, therapy efficacy and cost reduction.

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Abstract: Home PURPOSE OF THE CENTER: To develop the center to address state-of-the-art research, create innovating educational programs, and support technology transfers using commercially viable results to assist the Army Research Laboratory to develop the next generation Future Combat System in the telecommunications sector that assures prevention of perceived threats, and Non Line of Sight/Beyond Line of Sight lethal support.

Ion Suppression in Mass Spectrometry

Abstract: Background: Mass spectrometry (MS) is being introduced into a large number of clinical laboratories. It provides specificity because of its ability to monitor selected mass ions, sensitivity because of the enhanced signal-to-noise ratio, and speed because it can help avoid the need for intensive sample cleanup and long analysis times. However, MS is not without problems related to interference, especially through ion suppression effects. Ion suppression results from the presence of less volatile compounds that can change the efficiency of droplet formation or droplet evaporation, which in turn affects the amount of charged ion in the gas phase that ultimately reaches the detector. Content: This review discusses materials shown to cause ion suppression, including salts, ion-pairing agents, endogenous compounds, drugs, metabolites, and proteins. Experimental protocols for examining ion suppression, which should include, at a minimum, signal recovery studies using specimen extracts with added analyte, are also discussed, and a more comprehensive approach is presented that uses postcolumn infusion of the analyte to evaluate protracted ionization effects. Finally, this review presents options for minimizing or correcting ion suppression, which include enhanced specimen cleanup, chromatographic changes, reagent modifications, and effective internal standardization. Summary: Whenever mass spectrometric assays are developed, ion suppression studies should be performed using expected physiologic concentrations of the analyte under investigation.