“…Triplicate samples were taken from each plot, comprising a 1000 mL final sample after mixing, stored into amber glass bottles and transported to laboratory. Samples were analyzed for imazethapyr according to Santos et al (2008), imazapic by Reimche et al (2008), bispyribac-sodium by Kurz (2009) and penoxsulam by Zanella et al (2003), using High Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD) with a Varian system (Palo Alto, CA, USA) composed of ProStar 210 pump and ProStar 335 DAD detector. The column configuration consisted of a Phenomenex (USA) C-18 reversed-phase column (250 × 4.6 mm; 5 μm) and a Phenomenex C-18 guard column (10 × 4.6 mm; 5 μm).…”