A sensitive multiresidual analytical method for simultaneous analysis of multiresidual fungicides in environmental water samples was developed. The method was based on solid phase extraction (SPE) followed by high performance liquid chromatography tandem mass spectrometry (LC-MS/MS). Qualitative and quantitative detection for the analytes was carried out under the multiple reaction monitoring (MRM) in positive ionization mode after chromatography separation. In this method we have studied the conversion rule, identified the chromatogram retention time of Z-isomer and E-isomer of flumorph and dimethomorph, confirmed their chromatographic behavior by monitoring concentrations of two isomers of them at room temperature under sunlight and optimized parameters that may affect the SPE procedure efficiency: the column type, the wash solvent and the elution solvent. The recoveries of the SPE gave levels ranged from 70.18% to 108.87%, all recoveries were acceptable, with relative standard deviation (RSD) <= 16.7. The limit of quantification (LOQ, S/N = 10) varied between 0.003 and 0.03 mu g/L (except for fenhexamid 0.3 mu g/L). The developed method was applied for the determination of multiresidual fungicides in 100 tap water samples and 6 environmental samples collected from Liaoning province in China. Total fungicides were not found in tap water samples. Azoxystrobin (0.051 mu g/L), metalaxyl (0.217 mu g/L) and dimethomorph (Z, E) 0.015 mu g/L) were found in Pu river sample, dimethomorph (Z, E) (0.004 mu g/L) was found in Hun river sample, the highest concentration level of metalaxyl was 0.217 mu g/L in Pu river, the rest of fungicides remained undetected in river samples.
