Defense Date
2025
Document Type
Directed Research Project
First Advisor
Trista Wright
Second Advisor
Michelle Peace
Third Advisor
James Hutchings
Abstract
Meprobamate, carisoprodol, and naproxen are acidic/neutral drugs widely prescribed for muscle relaxation and inflammatory conditions, with frequent detection in forensic toxicology casework due to extensive clinical use. A method to qualitatively evaluate these compounds was developed to unify acid/neutral drug screening. This study incorporated blank blood, antemortem blood, postmortem blood, urine, and liver homogenate as representative biological matrices. Method validation was conducted in accordance with ANSI/ASB Standard 036 for Forensic Toxicology, encompassing key parameters including limit of detection (LOD), endogenous interferences, potential interferences, carryover, processed sample stability, and ionization suppression/enhancement. The validation was performed using the internal standards carisoprodol-D7, meprobamate-D7, and naproxen-D3 The limit of detection (LOD) was evaluated to determine the lowest concentration of the analytes that could be identified or differentiated from a blank matrix and was validated at a concentration of 0.5 mg/L for all three analytes, establishing a reliable concentration for detection in forensic casework. To meet validation requirements for the interference evaluation, the method had to confirm that no interfering signals originated from the matrix, internal standards, or commonly encountered analytes. No interferences of any type were observed during this evaluation, thereby ensuring specificity and reliability in measuring the target analytes. Carryover was evaluated to determine the presence of unintended analyte signal in samples after the analysis of a positive sample. The carryover evaluation was successful in this validation at concentrations of 75 mg/L and 100 mg/L, with no carryover observed in the samples, further supporting the overall robustness and reliability of the analytical method. Stability, defined as an analyte’s resistance to chemical change within a matrix under specific conditions and time intervals, was successfully validated for all three compounds when normalized to the corresponding internal standards. Ionization suppression and enhancement refers to the direct or indirect alteration of instrument response caused by co-eluting compounds. In this evaluation, deviations from the established threshold for ionization suppression and enhancement were observed, meaning that additional evaluations to determine the impact on other validation parameters will need to be completed. Based on these findings, the modified Anti-Epileptic Drugs Quantitation and Confirmation by LC-MS/MS method demonstrates potential as a validated approach for the qualitative confirmation of meprobamate, carisoprodol, and naproxen in forensic science casework.
Rights
© The Author(s)
Is Part Of
VCU Master of Science in Forensic Science Directed Research Projects
Date of Submission
12-1-2025