Analysis of terbumeton and its major metabolites by SPE and DAD-HPLC in soil bulk water

A rapid and inexpensive method for simultaneous quantification of terbumeton (TER), and its major potential metabolites (TED; terbumeton-desethyl, TOH; terbumeton-2-hydroxy and TID; terbumeton-deisopropyl) in soil bulk water (SBW) samples is proposed. The analytical method involves extraction-concentration from SBW samples using a graphitized carbon black (GCB) cartridge followed by their separation-detection by reversed-phase high-performance liquid chromatography analysis using a C-18 column and a diode array detector. A mobile phase of acetonitrile-0.005 mol L-1 phosphate buffer (pH 7.0) (35:65, v/v) at a flow rate of 0.8 mL min(-1) in isocratic elution mode has been used. After optimization of the extraction and separation conditions, this method can be used for the simultaneous determination of investigated compounds in the range of the international limits of 0.1 mu g L-1. For TER the detection limit was 0.009 mu g L-1 and it was 0.100, 0.550, and 0.480 mu g L-1 for TED, TOH, and TID, respectively. The recoveries of TER, TED, TOH, and TID from SBW samples, measured at three levels of concentration range, were found to be between 48.0 and 102.0%. The intra-day precision measured by relative standard deviation (RSD) was always lower than 9.0%.