Hexaconazole

All chemicals used were at least of analytical grade. Triazole standards including myclobutanil (MCBT), triadimefon (TDF), tebuconazole (TBZ), and hexaconazole (HCZ), were purchased from Dr Ehren-storfer GmbH (Germany). The stock standard solution of each triazole (1000 mg L⁻¹) were prepared by dissolving an appropriate amount in Methanol and stored in a refrigerator at 4 °C. Methanol and acetonitrile of HPLC-grade were obtained from Merck (Darmstadt, Germany). 1-Dodecanol (Sigma-Aldrich, Germany) and tributyldodecylphosphonium bromide (P₄₄₄₁₂Br) (Sigma-Aldrich, Switzerland) were used. Popping candies were obtained from local markets in Maha Sarakham, (Thailand). Type I deionized water (18.2 MΩ cm) used throughout this work was prepared using a RiOs simplicity 185 water purification system (Millipore, USA). Before subjecting to the HPLC system, all reagents were filtered through a 0.45 μm membrane filter.

All chromatography-grade solvents including acetonitrile, methanol, ethanol and propanol were purchased from Merck KGaA, Germany. Sodium dodecyl sulfate (SDS) was obtained from Merck Schuchardt OHG, Germany. Cetyltrimethylammonium bromide (CTAB) and sodium dodecylbenzene sulfonate (SDBS) were obtained from Sigma-Aldrich, Germany. The analytical standards of triazole including myclobutanil, triadimefon, tebuconazole, hexaconazole and diniconazole were purchased from Dr Ehren-storfer GmbH, Germany. Stock standard solution of each triazole fungicide (1000 μg mL⁻¹) was prepared by dissolving an appropriate amount in methanol and stored at 4 °C. Working standard solutions was prepared by diluting the stock standard solution with water. Deionized water (Millipore Waters, USA) with the resistivity of 18.2 MΩ cm was used throughout the experiments.