A threshold LC-MS/MS method for 92 analytes in oral fluid collected with the Quantisal® device

Salivary Biomarkers of Anti-Epileptic Drugs: A Narrative Review

Saliva is a biofluid that reflects general health and that can be collected in order to evaluate and determine various pathologies and treatments. Biomarker analysis through saliva sampling is an emerging method of accurately screening and diagnosing diseases. Anti-epileptic drugs (AEDs) are prescribed generally in seizure treatment. The dose-response relationship of AEDs is influenced by numerous factors and varies from patient to patient, hence the need for the careful supervision of drug intake. The therapeutic drug monitoring (TDM) of AEDs was traditionally performed through repeated blood withdrawals. Saliva sampling in order to determine and monitor AEDs is a novel, fast, low-cost and non-invasive approach. This narrative review focuses on the characteristics of various AEDs and the possibility of determining active plasma concentrations from saliva samples. Additionally, this study aims to highlight the significant correlations between AED blood, urine and oral fluid levels and the applicability of saliva TDM for AEDs. The study also focuses on emphasizing the applicability of saliva sampling for epileptic patients.

Liquid Chromatography High Resolution Mass Spectrometry in Forensic Toxicology: What Are the Specifics of Method Development, Validation and Quality Assurance for Comprehensive Screening Approaches?

The use of High Resolution Mass Spectrometry (HRMS) has increased over the past decade in clinical and forensic toxicology, especially for comprehensive screening approaches. Despite this, few guidelines of this field have specifically addressed HRMS issues concerning compound identification, validation, measurement uncertainty and quality assurance. To fully implement this technique, certainly in an era in which the quality demands for laboratories are ever increasing due to various norms (e.g. the International Organization for Standardization's ISO 17025), these specific issues need to be addressed. This manuscript reviews 26 HRMS-based methods for qualitative systematic toxicological analysis (STA) published between 2011 and 2021. Key analytical data such as samples matrices, analytical platforms, numbers of analytes and employed mass spectral reference databases/libraries as well as the studied validation parameters are summarized and discussed. The article further includes a critical review of targeted and untargeted data acquisition approaches, available HRMS reference databases and libraries as well as current guidelines for HRMS data interpretation with a particular focus on identification criteria. Moreover, it provides an overview on current recommendations for the validation and determination measurement uncertainty of qualitative methods. Finally, the article aims to put forward suggestions for method development, compound identification, validation experiments to be performed, and adequate determination of measurement uncertainty for this type of wide-range qualitative HRMS-based methods.

Simultaneous quantification of nineteen Non-Steroidal Anti-Inflammatory Drugs in oral fluid by liquid chromatography - high resolution mass spectrometry. Application on ultratrail runner's oral fluid

Non-steroidal anti-inflammatory drugs (NSAIDs) are a therapeutic class suspected to be used by ultratrail runners. The use of NSAIDs during ultratrails is known to be associated with various adverse effects. To study the prevalence of NSAIDs intake in ultratrail runners, oral fluid (OF) is a relevant matrix as it is noninvasive and easy to collect. The aim of our work was to develop and validate a liquid-liquid extraction followed by a LC-MS/HRMS method for the simultaneous quantification of nineteen NSAIDs in OF. After a comparison of different liquid-liquid extraction methods, a double step liquid-liquid extraction with chloroform was performed on OF collected with Quantisal®, with extraction recoveries higher than 90 %. An Accucore AQ column was selected for the chromatographic separation of NSAIDs. The Q Exactive Plus mass spectrometer operated in full scan and ddms2 mode after positive and negative electrospray ionization. Selectivity, carry-over, matrix effect, and linearity were validated for all NSAIDs. Within-day and between-day accuracy and precision were validated for all NSAIDs (< 15 % for QC samples and < 20 % for LLOQ), except within-day accuracy for the LLOQ of mefenamic acid. A stability study was also performed on OF at room temperature and +4 °C. The method was applied on OF from runners who participate to Ultra Trail du Mont-Blanc®.

Rethinking Drug Analysis in Healthcare: High-Throughput Analysis of 71 Drugs of Abuse in Oral Fluid using Ion Mobility - High Resolution Mass Spectrometry

We have identified a clinical need for a sensitive, specific, flexible, comprehensive, and affordable analytical technology to efficiently detect polydrug use. In addition, the current standard practise of surveilled urine sampling is uncomfortable for the patient, hence more patient-friendly sample collection methods are requested. To fill these needs, we have developed and validated a high-throughput liquid chromatography - high resolution mass spectrometry (LC-HRMS) method for analysis of DoA in oral fluid (OF). The method covers a panel of 71 substances including traditional drugs of abuse (DoA), prescription narcotics and new psychoactive substances (NPS), with a guaranteed limit of identification of <3 µg/L for 87% of the analytes. Method validation showed high accuracy (>99.7%), sensitivity (>99.7%) and specificity (100%). Most analytes had a high process efficiency during the salting out liquid-liquid extraction (SALLE) workup and no or only a minor matrix effect during the analysis. We have implemented this method in clinical routine, and present data from 18,579 OF samples collected during routine patient treatment in mainly psychiatric and addiction clinics in West Sweden between September 2020 and June 2021. 71% of the samples were positive and a total of 41,472 DoA findings were detected. Amphetamine (27%), buprenorphine (25%), nordiazepam (18%) and alprazolam (16%) were most prevalent. NPS were detected in 189 samples (1.0%). Occurrence of polydrug use was common, 34% of the positive samples contained three analytes or more and 12% six or more. To the best of our knowledge, this is the first method for comprehensive analysis of DoA in OF using HRMS and the largest dataset published on detection of DoA in OF. With the current complex and variable drug use pattern, this broad, cost-effective and reliable method has largely replaced immunoassay screening in urine in our laboratory.

Polydopamine coated hypodermic needles as a microextraction device for the determination of tricyclic antidepressants in oral fluid by direct infusion MS/MS

In-needle microextraction consists of the confinement of the sorbent, by coating or packing, inside a metallic needle. The size of the needles reduces the eluent requirements providing an efficient preconcentration of the analytes. In this work, hypodermic needles coated with polydopamine (PDA) are presented as microextraction devices to isolate six tricyclic antidepressants from oral fluid samples. The coating consists of the in-surface polymerization of dopamine at pH 8.5 and mild conditions (room temperature and water as solvent). The PDA coating over the stainless-steel surface confers the needles with a high extraction ability towards the target analytes. After the extraction, the eluates were analyzed by direct infusion MS spectrometry, working in multiple reaction monitoring (MRM) mode, which provided a sample throughput of 30 samples per hour. The variables affecting the synthesis (number of coating cycles, the concentration of dopamine, and needle surface pre-treatment) and the extraction (sample salinity, sample loading cycles, and the number of elution strokes) were studied in depth. Under the optimum conditions, a matrix-matched calibration model was built. The limits of quantification are between 2 and 5 ng mL⁻¹ with linear ranges up to 1000 ng mL⁻¹ for all analytes. The precision, expressed as relative standard deviation (RSD), is better than 10% for all analytes. Accuracy was calculated as recovery, and the obtained values are between 84% and 107%. A single-blind assay was also performed to evaluate the suitability of the method for real application.

Hypodermic needles coated with polydopamine for the extraction of antidepressants.