Fast urinary screening for imipramine and desipramine using on-line solid-phase extraction and selective...

Area of Science:

• Analytical Chemistry
• Clinical Chemistry
• Pharmaceutical Analysis

Background:

• Accurate and rapid screening of imipramine and its metabolites in urine is crucial for clinical toxicology and therapeutic drug monitoring.
• Existing methods may require complex procedures or individual analyte quantification, hindering timely decision-making in cases of overdose.

Purpose of the Study:

• To develop and validate a continuous-flow system for the simultaneous screening of imipramine and related metabolites in urine samples.
• To establish a method that simplifies analysis by using a single reagent for both elution and derivatization.
• To provide a total antidepressant index for quick assessment of potential overdosage.

Main Methods:

• Sequential solid-phase extraction (SPE) and derivatization in a continuous-flow manifold.
• Utilized a 50/50 (v/v) methanol/nitric acid mixture as both eluent and derivatizing reagent.
• Quantitatively retained drugs on an RP-C(18) column, followed by reaction with nitric acid to form a detectable blue dye monitored at 600 nm.

Main Results:

• The method demonstrated high sensitivity and selectivity, with minimal interference from endogenous and dietary compounds.
• A global signal was generated, allowing for the estimation of total antidepressant concentration without individual analyte quantification.
• Imipramine and its metabolites were successfully determined at therapeutic levels in urine samples.

Conclusions:

• The proposed continuous-flow system offers a sensitive, selective, and efficient approach for screening imipramine and metabolites in urine.
• The method facilitates rapid, total concentration-based assessment, aiding in timely clinical decisions regarding antidepressant overdosage.
• This innovative approach simplifies the analytical process, making it suitable for routine toxicological screening.