A Liquid-Chromatography High-Resolution Mass Spectrometry Method for Non-FDA Approved Benzodiazepines.

Area of Science:

• Forensic Chemistry
• Analytical Chemistry
• Pharmacology

Background:

• Benzodiazepines (BZDs) are commonly prescribed for anxiety and insomnia but are also subject to abuse.
• Numerous non-FDA approved BZDs and analogs exist, posing challenges for detection.
• Immunoassays are widely used for BZD screening but may lack specificity for novel compounds.

Observation:

• Fifteen non-FDA approved BZDs were tested using a ThermoFisher CEDIA® BZD immunoassay.
• Most compounds exhibited significant reactivity, except for ketazolam.
• This reactivity underscores the need for confirmatory methods like mass spectrometry.

Findings:

• A liquid chromatography-high resolution mass spectrometry (LC-HRMS) method was developed to detect 15 non-FDA approved BZDs.
• The method's limit of detection ranged from 1 to 50 ng/mL for most compounds.
• Matrix effects varied, with positive effects in urine and negative effects in serum.
• Clonazolam and etizolam were detected in a clinical case with half-lives of 3.6 and 4.8 hours, respectively.

Implications:

• Despite not detecting these compounds in previously BZD-positive urine samples, their abuse is increasing.
• Clinical and forensic toxicology laboratories should consider implementing LC-HRMS methods for detecting non-FDA approved BZDs.
• Accurate identification of novel psychoactive substances is vital for patient care and legal investigations.