The concentration of the fungicides pyrimethanil and imazalil in river water was determined by ultrasound-assisted emulsification micro-extraction (USAEME) and reversed-phase high performance liquid chromatography (RP-HPLC). The experimental parameters that affect the efficiency of USAEME were optimized, including the type and amount of extractant, pH value of the extraction solution, salt concentration of the extraction solution, extraction temperature and extraction time. The optimized experimental conditions resulted in an enrichment factor of 169 and 172 for pyrimethanil and imazalil, respectively. For pyrimethanil and imazalil, the linear ranges were 0.07–20 μg L−1 (r = 0.9964) and 0.02–15 μg L−1 (r = 0.9994), limits of detection (LOD) were 0.5 and 0.2 ng L−1 (S/N = 3), and the relative standard deviations were 2.7% and 3.4% (n = 6), respectively. This developed method is simple, fast, efficient and environmentally friendly, and has been successfully applied to the detection of pyrimethanil and imazalil in river water.
