Effects of mastery and coping rehearsal on competitive state anxiety

The effectiveness of mastery and coping rehearsal strategies on lowering competitive state anxiety prior to a gymnastic skill performance was assessed. [This is an excerpt from the abstract. For the complete abstract, please see the document.

MALDI-MS drug analysis in biological samples: opportunities and challenges

Drug analysis represents a large field in different disciplines. Plasma is commonly considered to be the biosample of choice for that purpose. However, concentrations often do not represent the levels present within deeper compartments and therefore cannot sufficiently explain efficacy or toxicology of drugs. MALDI-MS in drug analysis is of great interest for high-throughput quantification and particularly spatially resolved tissue imaging. The current perspective article will deal with challenges and opportunities of MALDI-MS drug analysis in different biological samples. A particular focus will be on hair samples. Recent applications were included, reviewed for their instrumental setup and sample preparation and pros and cons as well as future perspectives are critically discussed

Development and validation of a dynamic range-extended LC-MS/MS multi-analyte method for 11 different postmortem matrices for redistribution studies applying solvent calibration and additional 13C isotope monitoring

Postmortem redistribution (PMR) is one of numerous problems in postmortem toxicology making correct interpretation of measured drug concentrations difficult or even impossible. Time-dependent PMR in peripheral blood and especially in tissue samples is still under-explored. For further investigation, an easy applicable method for the simultaneous quantitation of over 80 forensically relevant compounds in 11 different postmortem matrices should be developed and validated overcoming the challenges of high inter-matrix and intra-matrix concentration variances. Biopsy samples (20mg) or body fluids (20μL) were spiked with an analyte mix and deuterated internal standards, extracted by liquid-liquid extraction, and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). For highest applicability, an easy solvent calibration was used. Furthermore, time-consuming dilution of high concentration samples showing detector saturation was circumvented by two overlapping calibration curves using 12C isotope monitoring for low concentrations and 13C isotopes for high concentration, respectively. The method was validated according to international guidelines with modifications. Matrix effects and extraction efficiency were strongly matrix and analyte dependent. In general, brain and adipose tissue produced the highest matrix effects, whereas cerebrospinal fluid showed the least matrix effects. Accuracy and precision results were rather matrix independent with some exceptions. Despite using an external solvent calibration, the accuracy requirements were fulfilled for 66 to 81% of the 83 analytes. Depending on the matrix, 75-93% of the analytes showed intra-day precisions at <20%. 12C and 13C calibrations gave comparable results and proved to be a useful tool in expanding the dynamic range

LC QTOF with SWATH acquisition: Systematic studies on its use for screenings in clinical and forensic toxicology and comparison with IDA and targeted MRM approaches

Forensic and clinical toxicological screening procedures are more and more employing LC-MS/MS techniques with information dependent acquisition (IDA) approaches. It is known that complexity of sample and settings of IDA might prevent important compounds from being triggered. Therefore, data independent acquisition methods (DIA) should be more suitable for systematic toxicological analysis (STA). The DIA method sequential window acquisition of all theoretical fragment-ion spectra (SWATH) which uses Q1 windows of 20-35 Da for data independent fragmentation, was systematically investigated for its suitability for STA. Quality of SWATH generated mass spectra were evaluated with regard to mass error, relative abundance of the fragments and library hits. With the Q1 window set to 20-25 Da, several precursors pass Q1 at the same time and are fragmented thus impairing the library search algorithms to a different extent: forward fit was less affected than reverse fit and purity fit. Mass error was not affected. Relative abundance of the fragments was concentration dependent for some analytes and was influenced by co-fragmentation, especially of deuterated analogues. Also the detection rate of IDA compared to SWATH was investigated in a forced coelution experiment (up to 20 analytes coeluting). Even using several different IDA settings it was observed that IDA failed to trigger relevant compounds. Screening results of 382 authentic forensic cases revealed that SWATH’s detection rate was superior to IDA, which failed to trigger about 10% of the analytes

Structural Characterization of the New Synthetic Cannabinoids CUMYL-PINACA, 5F-CUMYL-PINACA, CUMYL-4CN-BINACA, 5F-CUMYL-P7AICA and CUMYL-4CN-B7AICA

Synthetic cannabinoids are a group of new psychoactive compounds (NPS) that act as agonists at the cannabinoid receptor. First reported in 2008, they currently represent one of the largest groups of NPS that are monitored by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). Five samples (4 from the European RESPONSE project and one from daily casework) containing different synthetic cannabinoids were analyzed by a complex of analytical methods including gas chromatography − electron ionization mass spectrometry (GC-EI-MS), liquid chromatography − high resolution mass spectrometry (LC-HRMS), infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Five new synthetic cannabinoids containing a cumyl moiety as a linked group were identified: CUMYL-PINACA, 5F-CUMYL-PINACA, CUMYL-4CN-BINACA, 5F-CUMYL-P7AICA, CUMYL-4CN-B7AICA. 5F-CUMYL-PINACA and 5F-CUMYL-P7AICA as well as CUMYL-4CN-BINACA and CUMYL-4CN-B7AICA are constitutional isomers and only differ in the position of a nitrogen atom. The article contains all analytical data for a proper identification and differentiation of the five cumyl compounds

Parameter Optimization for Feature and Hit Generation in a General Unknown Screening Method—Proof of Concept Study Using a Design of Experiment Approach for a High Resolution Mass Spectrometry Procedure after Data Independent Acquisition

High resolution mass spectrometry and modern data independent acquisition (DIA) methods enable the creation of general unknown screening (GUS) procedures. However, even when DIA is used, its potential is far from being exploited, because often, the untargeted acquisition is followed by a targeted search. Applying an actual GUS (including untargeted screening) produces an immense amount of data that must be dealt with. An optimization of the parameters regulating the feature detection and hit generation algorithms of the data processing software could significantly reduce the amount of unnecessary data and thereby the workload. Design of experiment (DoE) approaches allow a simultaneous optimization of multiple parameters. In a first step, parameters are evaluated (crucial or noncrucial). Second, crucial parameters are optimized. The aim in this study was to reduce the number of hits, without missing analytes. The obtained parameter settings from the optimization were compared to the standard settings by analyzing a test set of blood samples spiked with 22 relevant analytes as well as 62 authentic forensic cases. The optimization lead to a marked reduction of workload (12.3 to 1.1% and 3.8 to 1.1% hits for the test set and the authentic cases, respectively) while simultaneously increasing the identification rate (68.2 to 86.4% and 68.8 to 88.1%, respectively). This proof of concept study emphasizes the great potential of DoE approaches to master the data overload resulting from modern data independent acquisition methods used for general unknown screening procedures by optimizing software parameters

Assessment of simpler calibration models in the development and validation of a fast postmortem multi-analyte LC-QTOF quantitation method in whole blood with simultaneous screening capabilities using SWATH acquisition

In postmortem toxicology, fast methods can provide a triage to avoid unnecessary autopsies. Usually, this requires multiple qualitative and quantitative analytical methods. The aim of the present study was to develop a postmortem LC-QTOF method for simultaneous screening and quantitation using easy sample preparation and reduced alternative calibration models. Hence, a method for 24 highly relevant substances in forensic toxicology was fully validated using the following calibration models: one-point external, one-point internal via corresponding deuterated standards, multi-point external daily calibration, and multi-point external weekly calibration. Two hundred microliters of postmortem blood were spiked with internal deuterated standard mixture and extracted by acetonitrile protein precipitation. Analysis was performed on a Sciex 6600 QTOF instrument with ESI+ mode using data-independent acquisition (DIA) namely sequential window acquisition of all theoretical mass spectra (SWATH). Validation of the different calibration models included selectivity, autosampler stability, recovery, matrix effects, accuracy, and precision for 24 substances. In addition, corresponding deuterated analogs of 52 substances were included to the internal standard mix for semi-quantitative concentration assessment. The simple protein precipitation provided recoveries higher than 55 and 75% for all analytes at low and high concentrations, respectively. Accuracy and precision criteria (bias and imprecision ± 15 and ± 20% near the limit of quantitation) were fulfilled by the different calibration models for most analytes. The validated method was successfully applied to more than 100 authentic postmortem samples and 3 proficiency tests. Furthermore, the one-point internal calibration via corresponding deuterated standard proved to be a considerably time saving technique for 76 analytes

Liquid chromatography–tandem mass spectrometry screening method using information‐dependent acquisition of enhanced product ion mass spectra for synthetic cannabinoids including metabolites in urine

The total number of synthetic cannabinoids (SCs) – a group of new psychoactive substances (NPS) – is increasing every year. The rapidly changing market demands the latest analytical methods to detect the consumption of SCs in clinical or forensic toxicology. In addition, SC metabolites must also be included in a screening procedure, if detection in urine is asked for. For that purpose, an easy and fast qualitative liquid chromatography—tandem mass spectrometry (LC−MS/MS) urine screening method for the detection of 75 SCs and their metabolites was developed and validated in terms of matrix effects, recovery, and limits of identification for a selection of analytes. SC metabolites were generated using in vitro human liver microsome assays, identified by liquid chromatography−high resolution tandem mass spectrometry (LC−HRMS/MS) and finally included to the MS/MS spectra in‐house library. Sample preparation was performed using a cheap‐and‐easy salting‐out liquid–liquid extraction (SALLE) after enzymatic hydrolysis. Method validation showed good selectivity, limits of identification down to 0.05 ng/mL, recoveries above 80%, and matrix effects within ±25% for the selected analytes. Applicability of the method was demonstrated by detection of SC metabolites in authentic urine samples

Importance of Toxicokinetics to Assess the Utility of Zebrafish Larvae as Model for Psychoactive Drug Screening Using Meta-Chlorophenylpiperazine (mCPP) as Example

The number of new psychoactive substances (NPS) increases rapidly, harming society and fuelling the need for alternative testing strategies. These should allow the ever-increasing number of drugs to be tested more effectively for their toxicity and psychoactive effects. One proposed strategy is to complement rodent models with zebrafish () larvae. Yet, our understanding of the toxicokinetics in this model, owing to the waterborne drug exposure and the distinct physiology of the fish, is incomplete. We here explore the toxicokinetics and behavioral effects of an NPS, meta-chlorophenylpiperazine (mCPP), in zebrafish larvae. Uptake kinetics of mCPP, supported by toxicokinetic modeling, strongly suggested the existence of active transport processes. Internal distribution showed a dominant accumulation in the eye, implying that in zebrafish, like in mammals, melanin could serve as a binding site for basic drugs. We confirmed this by demonstrating significantly lower drug accumulation in two types of hypo-pigmented fish. Comparison of the elimination kinetics between mCPP and previously characterized cocaine demonstrated that drug affinities to melanin in zebrafish vary depending on the structure of the test compound. As expected from mCPP-elicited responses in rodents and humans, zebrafish larvae displayed hypoactive behavior. However, significant differences were seen between zebrafish and rodents with regard to the concentration-dependency of the behavioral response and the comparability of tissue levels, corroborating the need to consider the organism-internal distribution of the chemical to allow appropriate dose modeling while evaluating effects and concordance between zebrafish and mammals. Our results highlight commonalities and differences of mammalian versus the fish model in need of further exploration