Determination of benzodiazepines in forensic samples by HPLC with photo-diode array detection

Area of Science:

• Forensic Toxicology
• Analytical Chemistry
• Pharmacology

Background:

• Benzodiazepines are widely prescribed drugs with potential for abuse.
• Accurate quantification of benzodiazepines and their metabolites in biological matrices is crucial for forensic investigations.
• Existing analytical methods may lack the speed, robustness, or sensitivity required for routine forensic toxicology.

Purpose of the Study:

• To develop and validate a high-performance liquid chromatographic (HPLC) method for the simultaneous analysis of benzodiazepines and their metabolites.
• To establish a sensitive and robust analytical procedure suitable for routine forensic toxicological applications.
• To assess the method's performance in real-world forensic case analyses.

Main Methods:

• Liquid-liquid extraction using n-hexane:ethylacetate.
• Gradient elution on a C8 reversed-phase column with a non-electrolyte eluent.
• Photo diode array (PDA) detection for rapid identification and quantification.

Main Results:

• The method achieved detection limits of 10-30 ng and quantification limits of 0.05 µg/mL using 1 mL of sample.
• The procedure demonstrated high sensitivity, purity checking, and accurate quantitation.
• The non-electrolyte eluent resulted in a robust method, free from technical issues and long rinsing times.

Conclusions:

• The developed HPLC-PDA method is a rapid, sensitive, and robust technique for analyzing benzodiazepines and metabolites in forensic samples.
• The method is suitable for routine application in forensic toxicology, including blood, urine, stomach content, and tissue analysis.
• The successful application in approximately 30 positive forensic cases validates its practical utility.