Automated method to determine pharmaceutical compounds in wastewater using on-line solid-phase extraction coupled to...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Pharmaceutical compounds are emerging contaminants in wastewater.
• Accurate quantification of these compounds is crucial for environmental risk assessment.

Purpose of the Study:

• To develop and validate an automated method for determining pharmaceutical compounds in wastewater.
• To enable routine environmental monitoring with high sensitivity and efficiency.

Main Methods:

• On-line solid-phase extraction (SPE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS).
• Method validation according to international guidelines, including MDL, MQL, linearity, precision, and matrix effects.
• Isotope dilution calibration to minimize matrix effects.

Main Results:

• The automated method achieved rapid analysis (24 min run time) with high precision (intra-day <10%, inter-day <17%).
• Method detection limits (MDL) ranged from 1x10^-6 to 1 μg/L, and quantification limits (MQL) from 0.001 to 3 μg/L.
• Caffeine was the most frequently detected compound in wastewater samples (up to 715 μg/L).

Conclusions:

• The developed automated on-line SPE-LC-MS/MS method is suitable for routine analysis of pharmaceutical compounds in wastewater.
• The method offers high efficiency, minimal sample handling, and reliable results for environmental applications.
• It provides a robust tool for monitoring pharmaceutical pollution in aquatic environments.