Comprehensive screening procedure for diuretics in urine by high-performance liquid chromatography

Area of Science:

• Analytical Chemistry
• Pharmacology
• Clinical Toxicology

Background:

• Diuretics are commonly prescribed medications with potential for misuse.
• Accurate and rapid detection of diuretics in biological samples is crucial for clinical and forensic toxicology.
• Existing methods may lack the sensitivity or speed required for routine screening.

Purpose of the Study:

• To develop and validate a rapid and reliable high-performance liquid chromatography (HPLC) screening method for 23 diuretics in human urine.
• To establish the sensitivity, specificity, and applicability of the developed method for detecting various diuretic classes.

Main Methods:

• Urine samples (2 ml) were extracted under acidic and basic conditions, then pooled and reconstituted in methanol.
• Separation was performed using a Hewlett-Packard Hypersil ODS C18 column with a gradient mobile phase.
• Detection was achieved using a diode array ultraviolet detector set at 230 and 275 nm.

Main Results:

• The method demonstrated a lower limit of detection ranging from 0.5 to 1.5 µg/ml for most diuretics, with an average of 1.0 µg/ml.
• Amiloride, ethacrynic acid, and probenecid had a higher detection limit of 5 µg/ml.
• No significant interference from the biological matrix was observed, and amiloride was detected 4 hours post-administration.

Conclusions:

• A robust HPLC method for the simultaneous detection of 23 diuretics in urine has been successfully developed.
• The method is sensitive, reliable, and suitable for routine screening in clinical and forensic settings.
• The developed procedure aids in monitoring diuretic use and detecting potential abuse.