Determination of herbicide terbuthylazine and its major hydroxy and dealkylated metabolites in constructed wetland sediments using solid phase extraction and high performance liquid chromatography-diode array detection

Abstract

This paper describes the development of a new analytical method for the analysis of the herbicide TER and its degradation products in sediment samples. This method, based on high-performance liquid chromatography with diode-array detection, was validated for the simultaneous determination of TER and its major metabolites, desethylterbuthylazine, desisopropyatrazine, hydroxyterbuthylazine, desethylhydroxyatrazine and desethylhydroxyterbuthylazine. This method includes a cleanup and a solid-phase extraction step, using ultra-pure water and MCX cartridges respectively, with an overall recovery efficiency ranging from 89.3 to 97.9%. The statistical evaluation demonstrates good linearity with correlation coefficients >0.999 and adequate accuracy and precision for all analytes, with% Er and RSD values up to 10.5% and 8.3% respectively. The limit of detection for all substances was found to be 3.3 ng g⁻¹. This method can be employed in remediation studies of TER and its major metabolites in sediments of constructed wetlands leading to useful results for the degradation and dispersion of TER in the vertical profile of wetland sediment substrates.

Keywords:

• terbuthylazine
• metabolites
• solid phase extraction
• sediments
• constructed wetlands
• HPLC

Acknowledgement

We would like to acknowledge Thermo Electron (Waltham, MA) for partially supporting this project through a research grant. Dr Nikolaos Papadopoulos is grateful to the Public Benefit Foundation of Alexandros S. Onassis for supporting him through a research scholarship (2004–2007).