43 research outputs found
Analytical Profiling of Airplane Wastewater - a New Matrix for Mapping Worldwide Patterns of Drug Use and Abuse
Abstract
There is limited knowledge on the global prescription and consumption patterns of therapeutic (TD) and illicit drugs (ID). Pooled urine analysis and wastewater-based epidemiology (WBE) has been used for local-based drug screening. It is, however, difficult to study the global epidemiology due to difficulties in obtaining samples. The aims of the study were to test the detectability of TD and ID in airplane wastewater samples categorized according to their geographical origin.
Wastewater samples (n= 17) were collected from long-distance flights and prepared with enzymatic conjugate cleaving followed by either precipitation or solid phase extraction. Aliquots were analysed on various liquid chromatography – mass spectrometers. TDs were grouped according to their Anatomical Therapeutic Chemical (ATC) codes.
Identification confidence was assigned to three levels based on variables including detection on multiple instruments and number of targets per compound. A total of 424 compounds were identified across all samples, distributed on 87 unique TD and 2 ID. Two principal components in a principal component analysis separated three clusters of wastewater samples corresponding to geographical origin of the airplanes with therapeutic subgroup ATC codes as variables. Airplane wastewater analysis is useful for identifying targets for WBE and toxicological analysis and explore drug use and abuse patterns.</jats:p
A New Strategy for Efficient Retrospective Data Analyses for Designer Benzodiazepines in Large LC-HRMS Datasets
The expanding and dynamic market of new psychoactive substances (NPSs) poses
challenges for laboratories worldwide. The retrospective data analysis (RDA) of previously
analyzed samples for new targets can be used to investigate analytes missed in the first
data analysis. However, RDA has historically been unsuitable for routine evaluation
because reprocessing and reevaluating large numbers of forensic samples are highly
work- and time-consuming. In this project, we developed an efficient and scalable
retrospective data analysis workflow that can easily be tailored and optimized for
groups of NPSs. The objectives of the study were to establish a retrospective data
analysis workflow for benzodiazepines in whole blood samples and apply it on previously
analyzed driving-under-the-influence-of-drugs (DUID) cases. The RDA workflow was
based on a training set of hits in ultrahigh-performance liquid
chromatography–quadrupole time-of-flight–mass spectrometry (UHPLC-QTOF-MS)
data files, corresponding to common benzodiazepines that also had been analyzed
with a complementary UHPLC–tandem mass spectrometry (MS/MS) method.
Quantitative results in the training set were used as the true condition to evaluate
whether a hit in the UHPLC-QTOF-MS data file was true or false positive. The training
set was used to evaluate and set filters. The RDA was used to extract information from 47
DBZDs in 13,514 UHPLC-QTOF-MS data files from DUID cases analyzed from 2014 to
2020, with filters on the retention time window, count level, and mass error. Sixteen
designer and uncommon benzodiazepines (DBZDs) were detected, where 47
identifications had been confirmed by using complementary methods when the case
was open (confirmed positive finding), and 43 targets were not reported when the case
was open (tentative positive finding). The most common tentative and confirmed findings
were etizolam (n = 26), phenazepam (n = 13), lorazepam (n = 9), and flualprazolam (n = 8).
This method efficiently found DBZDs in previously acquired UHPLC-QTOF-MS data files,
with only nine false-positive hits. When the standard of an emerging DBZD becomes
available, all previously acquired DUID data files can be screened in less than 1 min. Being
able to perform a fast and accurate retrospective data analysis across previously acquired
data files is a major technological advancement in monitoring NPS abuse
How to perform spectrum-based LC-HR-MS screening for more than 1,000 NPS with HighResNPS consensus fragment ions.
IntroductionThe ever-changing market of new psychoactive substances (NPS) poses challenges for laboratories worldwide. Analytical toxicologists are constantly working to keep high-resolution mass spectrometry (HR-MS) screening libraries updated for NPS. This study sought to use the online crowd-sourced HighResNPS database for spectrum comparison screening, thereby broadening its utility to all HR-MS instruments.MethodHighResNPS allows formation of a set of consensus fragment ions for a NPS and prioritises among multiple entries of collision-induced fragment ions. A subset of 42 NPS samples was analysed in data-independent acquisition (DIA) and data-dependent acquisition (DDA) modes on two different instruments. HighResNPS-computed spectra were generated with either Absolute (all fragment ions set to 100%) or Fractional (50% intensity reduction of former fragment ion) intensity. The acquired NPS data were analysed using the consensus library with computed ion intensities and evaluated with vendor-neutral screening software.ResultsOverall, of the 42 samples, 100% were identified, with 88% identified as the top candidate. Three samples had the correct candidate proposed as the second highest ranking NPS. In all three of those samples, the top proposed candidate was a positional isomer or closely related compound. Absolute intensity assignment provided identical scoring between the top two proposed compounds in two samples with DIA. DDA had a slightly higher identification rate in the spectra comparison screening with fractional intensity assignment, but no major differences were observed.ConclusionThe fractional intensity assignment was slightly more advantageous than the absolute assignment. It was selective between proposed candidates, showed a high identification rate and had an overall higher fragmentation scoring. The candidates proposed by the HighResNPS library spectra comparison simplify the determination of NPS for researchers and toxicologists. The database provides free monthly updates of consensus spectra, thereby enabling laboratories to stay at the forefront of NPS screening by LC-HR-MS with spectra screening software