Solid phase extraction of morphine and its metabolites from postmortem blood

Area of Science:

• Forensic Chemistry
• Analytical Chemistry
• Pharmacology

Background:

• Accurate quantification of morphine and its metabolites in postmortem blood is essential for forensic investigations.
• Existing methods may lack the speed, sensitivity, or comprehensiveness required for routine analysis.

Purpose of the Study:

• To develop and validate a simple, rapid, and reproducible high-performance liquid chromatographic (HPLC) method.
• To enable simultaneous determination of morphine-3-glucuronide, morphine-6-glucuronide, normorphine, and morphine in postmortem blood samples.

Main Methods:

• Solid-phase extraction (SPE) using C18 Sep-Pak cartridges for sample preparation.
• Reverse-phase ion-pair chromatography on a C18 bonded column for separation.
• Sequential electrochemical detection (ECD) and ultraviolet (UV) detection at 210 nm for quantitation.

Main Results:

• The method achieved a lower limit of detection of 10 ng/ml for all analytes using ECD.
• A linear response was observed from 10 ng/ml up to 5000 ng/ml.
• Intra- and inter-assay coefficients of variation ranged from 3-13% for all analytes, demonstrating good reproducibility.

Conclusions:

• The developed HPLC method is suitable for the simultaneous measurement of morphine and its major glucuronide and demethylated metabolites in postmortem blood.
• The method's simplicity, speed, and reproducibility make it a valuable tool for forensic toxicology.
• This analytical approach aids in understanding opioid metabolism and distribution in postmortem cases.