Tetracycline and macrolide antibiotics: Trace analysis in water and wastewater using solid phase extraction and liquid chromatography-tandem mass spectrometry

Liquid chromatography-tandem mass spectrometry (LC/MS/MS) provides a sensitive, reproducible, and specific instrumental method for quantifying agricultural antibiotics in a variety of matrices. Sensitivity can be enhanced and interferences minimized by concentrating these compounds using solid phase extraction. Comparison of polymeric and reverse phase extraction cartridges suggests that either phase may provide quantitative results. Buffering and/or pH adjustment improves the recovery of these highly polar and sometimes problematic compounds. Tetracycline method detection limits determined in water are between 0.2 and 0.3 μg/L, and between 1.0 and 2.0 μg/L in buffered wastewater. Macrolides, lincomycin, and tiamulin method detection limits determined in buffered water are between 0.4 and 1.4 μg/L. Macrolides and tiamulin detection limits are between 1.0 and 3.0 μg/L in wastewater.