Optimisation of the analysis of anti-influenza drugs in wastewater and surface water

Abstract

We optimised the simultaneous analysis of four analytes, namely three anti-influenza drugs (oseltamivir (OS), zanamivir (ZAN) and amantadine (AMN)) and one metabolite of OS (oseltamivir carboxylate (OC)), in sewage treatment plant (STP) influent and effluent by verifying the types and conditions of solid phase extraction (SPE) appropriate for LC-MS/MS analysis. In summary, these target analytes were extracted from aqueous samples (30–50 mL) by using strong cation-exchange SPE cartridges (500 mg adsorbent) under acidic conditions (pH 3–4). After washing of the cartridges with acidified water (pH 3.0, 3 mL) and methanol (3 mL), the analytes were eluted with a mixed solvent (2 mL) of 10% (v/v) triethylamine in a 1:1 (v/v) mixture of acetone and water. Application of this technique to the target compounds should yield a comprehensive understanding of the occurrence and fate of anti-influenza drugs in the water environment.

Keywords:

• LC-MS/MS
• oseltamivir
• pharmaceuticals
• water environment
• zanamivir

Acknowledgements

We thank GlaxoSmithKline (United Kingdom) for providing the analytical-grade ZAN. We also thank the staff of the STPs for sampling the water. We acknowledge the Japan Science and Technology Agency, the Japan Society for the Promotion of Science, the Ministry of Land, Infrastructure, Transport and Tourism of Japan, and the Ministry of Education, Culture, Sports, Science and Technology of Japan for funding in the form of research grants and scholarships.

Supplemental material

Supplemental material relating to this article is available online.