Targeted LC-MS/MS method for quantifying respiratory pharmaceuticals in wastewater.

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Public Health

Background:

• Wastewater-based epidemiology (WBE) monitors population health by analyzing wastewater.
• Sensitive methods are needed to detect respiratory medications in wastewater.
• Existing methods lack sensitivity for complex wastewater matrices.

Purpose of the Study:

• To develop and validate a sensitive LC-MS/MS method for detecting 10 common respiratory pharmaceuticals in wastewater.
• To improve wastewater analysis for public health surveillance.

Main Methods:

• Developed a liquid chromatography-mass spectrometry (LC-MS)/MS method with multiple reaction monitoring.
• Integrated freeze-drying for preconcentration and online solid-phase extraction for cleanup.
• Utilized stable isotope-labeled internal standards (SILs) to correct for matrix effects.

Main Results:

• Achieved low detection and quantification limits (0.7-19 ng L⁻¹ and 3-125 ng L⁻¹).
• Demonstrated high recoveries (82-194%) and precision (<7.2% RSD).
• Successfully detected 9 of 10 target compounds in wastewater samples, with 6 above quantification limits.

Conclusions:

• The validated LC-MS/MS method is robust, high-throughput, and requires low sample volumes.
• This method enables reliable detection of respiratory drugs in wastewater.
• Supports WBE for pharmaceutical use surveillance and public health monitoring.