High-performance liquid chromatographic determination of ¹⁴C-labelled terbuthylazine and principal degradates in percolation water and soil extracts from leaching experiments

A new very porous polystyrene-divinylbenzene copolymer with large surface area as an adsorber for solid-phase extraction (SPE), was used for the analyses of terbuthylazine and principal degradates. It showed good recovery rates even for the dealkylated hydroxy metabolites. The polymer was treated similarly to a reversed-phase material, samples of 1000 ml showed no breakthrough for most of the terbuthylazine degradates. A detection limit of 0.1 μg/l could be reached even for the most polar compounds (de-tert.-butyldeethylterbuthylazine and de-tert.-butylhydroxyterbuthylazine) with recovery rates of 22 and 30%. Percolated water and soil extracts from column experiments, obtained with water and methanol, were analysed using the copolymer sorbent. Analyses were performed on a HPLC system with UV-Vis detection and a scintillation counter. The compounds were separated on a RP-8 column with an acetonitrile-phosphate-buffer gradient. In addition to terbuthylazine applied 2 months prior to extraction, deethyl-and hydroxyterbuthylazine were detected in the soil extracts; de-tert.-butylterbuthylazine was found only in traces.