Qualitative and quantitative determination of xylazine in oral fluid.

Xylazine has emerged in recent years as a dangerous adulterant in illicit fentanyl use, and methods for the detection of xylazine in toxicology panels are still lagging. We developed methods for the screening and quantitation of xylazine in oral fluid (OF), a popular testing medium due to its ease of collection and reflection of presence in blood for many classes of drugs. Enzyme-linked immunosorbent assays were employed for the rapid screening of xylazine directly from the collection device buffer with a cutoff of 1 ng/mL. Solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry facilitated the confirmation and quantification of xylazine as low as 0.1 ng/mL and a dynamic range of 0.1-25 ng/mL. Selectivity, ionization suppression, processed sample stability, and dilution effect were also assessed. The method was validated through the American National Standards Institute/American Academy of Forensic Sciences Standards Board (ANSI/ASB) Standard 036, first edition from 2019, and found to be accurate, precise, and robust. Living human subject OF samples collected within substance use disorder and therapeutic drug monitoring clinics received between September 2023 and January 2024, with the specific request to test for xylazine (n = 57), were screened. Presumptive positive samples were confirmed using the validated method. Xylazine confirmed living human subject OF sample concentrations ranged from 1.2 to 23.3 ng/mL.

Quantitation of Δ8-THC, Δ9-THC, Cannabidiol and 10 Other Cannabinoids and Metabolites in Oral Fluid by HPLC-MS-MS.

Quantitative analysis of Δ9-tetrahydrocannabinol (Δ9-THC) in oral fluid has gained increasing interest in clinical and forensic toxicology laboratories. New medicinal and/or recreational cannabinoid products require laboratories to distinguish different patterns of cannabinoid use. This study validated a high-performance liquid chromatography-tandem mass spectrometry method for 13 different cannabinoids, including (-)-trans-Δ8-tetrahydrocannabinol (Δ8-THC), (-)-trans-Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD), Δ9-tetrahydrocannabinolic acid-A (Δ9-THCA-A), cannabidiolic acid (CBDA), 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-Δ9-THC), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (Δ9-THCCOOH), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabidiorcol (CBD-C1), cannabichromene (CBC), cannabinol (CBN) and cannabigerol (CBG), in oral fluid. Baseline separation was achieved in the entire quantitation range between Δ9-THC and its isomer Δ8-THC. The quantitation range of Δ9-THC, Δ8-THC and CBD was from 0.1 to 800 ng/mL. Two hundred human subject oral fluid samples were analyzed with this method after solid phase extraction. Among the 200 human subject oral fluid samples, all 13 cannabinoid analytes were confirmed in at least one sample. Δ8-THC was confirmed in 11 samples, with or without the presence of Δ9-THC. A high concentration of 11-OH-Δ9-THC or Δ9-THCCOOH (>400 ng/mL) was confirmed in three samples. CBD, Δ9-THCA-A, THCV, CBN and CBG were confirmed in 74, 39, 44, 107 and 112 of the 179 confirmed Δ9-THC-positive samples, respectively. The quantitation of multiple cannabinoids and metabolites in oral fluid simultaneously provides valuable information for revealing cannabinoid consumption and interpreting cannabinoid-induced driving impairment.

Determination of Dextromethorphan in Oral Fluid by LC-MS-MS.

Dextromethorphan (DXM) is an antitussive drug found in commonly used nonprescription cold and cough medications. At low doses, DXM is a safe drug that does not produce adverse reactions. However, abuse of DXM has been reported among adolescents and young adults using the drug at higher doses. DXM is not a scheduled drug in the USA, and the primary reason for its abuse is the ease of availability. DXM is available to purchase in the form of over-the-counter cough medications, such as Robitussin(®) and Coricidin(®), or it can be purchased over the Internet in the form of a powder. In this research work, we developed an LC-MS-MS method that can quantify DXM and dextrorphan (DXO) in oral fluid in a high-throughput toxicology laboratory setting. The developed method was validated according to the Scientific Working Group for Forensic Toxicology guidelines. The linear dynamic range was 5-100 ng/mL with a lowest limit of quantitation (LLOQ) of 5.0 ng/mL for DXM and DXO. Overall, the results of the accuracy and the precision values were within the acceptance criteria for both drugs. In addition, selectivity, matrix effect and recovery were calculated for the LC-MS-MS method. Authentic samples (n = 59) were tested to evaluate the applicability of the method. Thirty samples were found to be positive for DXM and DXO and two samples were found to be positive for DXM only.

Quantitative measurement of XLR11 and UR-144 in oral fluid by LC-MS-MS.

Availability and consumption of synthetic cannabinoids have risen recently in the USA and Europe. These drugs have adverse effects, including acute psychosis and bizarre behavior. In 2012, the United States Drug Enforcement Agency permanently banned five of the synthetic cannabinoids and in 2013, temporarily added XLR11, UR-144 and AKB48 to Schedule I of the Controlled Substances Act. As synthetic cannabinoid strains are added to the Schedule I list, new strains are being introduced into the market. XLR11 and UR-144 are two of the most recent additions to the synthetic cannabinoid drug class. To test collected oral fluid samples for XLR11 and UR-144, we developed a bioanalytical method that initially purifies the sample with solid-phase extraction and then quantitatively identifies the drugs with ultra-high-performance liquid chromatography-tandem mass spectrometry. The method was validated according to United States Food and Drug Administration guidelines and Scientific Working Group for Forensic Toxicology guidelines and the validation data showed that the method is an accurate, precise, robust and efficient method suited for high-throughput toxicological screening applications. We tested human subject samples with the developed method and found the presence of parent drugs (XLR11 and UR-144), their metabolites and their pyrolysis products in oral fluid.

Quantitative measurement of synthetic cathinones in oral fluid.

Synthetic cathinones have recently emerged as a substitute for common drugs of abuse. Synthetic cathinones can elicit powerful adverse effects such as delusions, hallucinations and potentially dangerous behavior. To develop a method to analyze 10 synthetic cathinones in oral fluid, we implemented a combined approach of solid-phase extraction and ultra-high-performance liquid chromatography-tandem mass spectrometry. The developed analytical procedure was a sensitive, precise and selective method suited for high-throughput toxicological screening of synthetic cathinones. The method was validated using standard parameters including accuracy, precision, linearity, sensitivity, matrix effect and recovery. Human subject samples were analyzed using the developed method to demonstrate the applicability of the method.