Sensitive determination of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol and complementary cannabinoids in hair using alkaline digestion and mixed-mode solid phase extraction followed by liquid-chromatography-tandem mass spectrometry.

Hair drug testing can be used for the evaluation of cannabis use with a large detection window, and is required for professional driving license granting in Brazil. A positive hair result for cannabis use requires quantification of the metabolite THC-COOH above the cutoff value of 0.2 ng/g.

Simple extraction of toxicologically relevant psychotropic compounds and metabolites from whole blood using mini-QuEChERS followed by UPLC-MS/MS analysis.

The determination of psychotropic drugs and metabolites in blood is relevant in the context of both therapeutic drug monitoring and clinical and forensic toxicology. LC-MS/MS is the preferred method for these assays. However, LC-MS/MS is particularly susceptible to matrix ionization effects and appropriate sample preparation is required to minimize these effects.

Blood phosphatidyl ethanol levels as a tool to detect alcohol misuse in trauma patients.

Introduction: There is a strong need for a reliable marker of harmful alcohol consumption to identify injured patients that can benefit from alcohol interventions, and blood phosphatidyl ethanol (PEth) has not previously been tested on this population. This study aims to compare the performance of blood PEth concentration, blood alcohol concentration (BAC) and the Alcohol Use Disorders Identification Test Consumption (AUDIT-C) for the screening of alcohol misuse in trauma patients.

Methods: Prospective cross-sectional study of 238 adult patients presenting in the emergency department with any type of trauma.

Validation of an analytical method for the simultaneous determination of 16 drugs and metabolites in hair in the context of driving license granting.

The use of psychoactive substances has been associated with increased risk for traffic accidents. Hair testing has become a routine practice in clinical and forensic toxicological laboratories, with a unique perspective in the investigation of drug consumption. The study aimed to develop and validate a UHPLC-MS/MS method for the determination of multiple drugs in hair, to be used for toxicological examination in driving license granting.

Determination of cannabinoids in plasma using salting-out-assisted liquid-liquid extraction followed by LC-MS/MS analysis.

The detection of the markers of Cannabis consumption in biological specimens is an important task for drug testing laboratories in varous contexts. A simple assay combining salting-out assisted liquid-liquid extraction sample preparation and LC-MS/MS analysis was applied to the measurement of Δ -tetrahydrocannabinol, 11-nor-9-carboxy-Δ -tetrahydrocannabinol (THC-COOH), 11-hydroxy-Δ -tetrahydrocannabinol, cannabinol and cannabidiol concentrations in 100 μl plasma specimens. The assay had linearity of 1-100 ng ml for THC-COOH and 0.

Determination of Endogenous Concentrations of Uracil and Dihydrouracil in Dried Saliva Spots by LC-MS/MS: Method Development, Validation, and Clinical Application.

Background: The aim of this study was to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for the measurement of uracil (U) and dihydrouracil (UH2) concentrations in dried saliva spots (DSSs), for the evaluation of dihydropyrimidine dehydrogenase (DPD) enzyme activity.

Results: Nine 18-mm diameter DSS discs were extracted with acetate:isopropyl alcohol (85:15, vol/vol) and analyzed by LC-MS/MS. The assay was linear in the range of 10-1000 ng·mL, with accuracy between 89% and 112% and precision between 5.

DPD functional tests in plasma, fresh saliva and dried saliva samples as predictors of 5-fluorouracil exposure and occurrence of drug-related severe toxicity.

Objective: to evaluate plasma and salivary uracil (U) to dihydrouracil (UH2) ratios as tools for predicting 5-fluorouracil systemic exposure and drug-related severe toxicity, and clinically validate the use of dried saliva spots (DSS) as an alternative sampling strategy for dihydropyrimidine dehydrogenase (DPD) deficiency assessment.

Methods: Pre-chemotherapy plasma, fresh saliva and DSS samples were obtained from gastrointestinal patients (N = 40) for measurement of endogenous U and UH2 concentrations by LC-MS/MS. A second plasma sample collected during 5FU infusion was used for 5FU area under the curve (AUC) determination by HPLC-DAD.