A high-performance thin-layer chromatographic technique to screen cocaine in urine samples

Area of Science:

• Analytical Chemistry
• Forensic Toxicology
• Chromatographic Methods

Background:

• Urine drug screening commonly uses immunoassay followed by GC/MS confirmation.
• Alternative chromatographic methods like TLC and GC are valuable for forensic drug abuse screening.
• The need for reliable methods to detect cocaine and its metabolites in biological matrices persists.

Purpose of the Study:

• To evaluate the capability of High Performance Thin-Layer Chromatography (HPTLC) for qualitative cocaine identification in urine.
• To assess HPTLC's ability to differentiate cocaine from common interfering substances.
• To determine the utility of HPTLC in forensic toxicology for drug abuse detection.

Main Methods:

• Analysis of twenty urine samples from drug addicts using the HPTLC method.
• Detection of unaltered cocaine in urine samples.
• Detection of cocaine formed after methylation of benzoylecgonine with diazomethane.

Main Results:

• High Performance Thin-Layer Chromatography (HPTLC) successfully detected cocaine in all tested urine samples.
• The method demonstrated the ability to identify both unaltered cocaine and cocaine derived from its primary metabolite, benzoylecgonine.
• Interfering substances such as local anesthetics, caffeine, and nicotine were effectively discriminated.

Conclusions:

• The proposed HPTLC method is a viable tool for the qualitative identification of cocaine in biological matrices.
• HPTLC provides a reliable and effective means for detecting cocaine abuse in forensic settings.
• This chromatographic technique offers a valuable alternative for drug screening in urine samples.