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Strobilurins constitute a new class of fungicides that is the most widely used in the world. The present study was conducted to investigate the aquatic toxicity of 3 common strobilurin fungicides (kresoxim-methyl, pyraclostrobin, and trifloxystrobin) to Daphnia magna. The neonate acute immobilization test showed that the 48-h 50% effective concentration (EC50) values of kresoxim-methyl, pyraclostrobin, and trifloxystrobin were 443.3µg/L, 20.9µg/L, and 23.0µg/L, respectively. In addition, the 3 strobilurins significantly induced activity of the important detoxification enzyme glutathione S-transferase (GST) in D. magna, and there was a significant positive relationship between GST activity and immobility of D. magna after acute exposure. The 3 strobilurins showed higher toxicity to D. magna embryos, and the 48-h EC50 were 157.3µg/L, 3.9µg/L, and 1.7µg/L for kresoxim-methyl, pyraclostrobin, and trifloxystrobin, respectively. The 21-d chronic test revealed that the strobilurins could also significantly affect the reproduction, development, and growth of D. magna at sublethal concentrations. The lowest-observed-effect concentrations of kresoxim-methyl, pyraclostrobin, and trifloxystrobin for reproduction were 20µg/L, 0.15µg/L, and 0.2 µg/L, respectively, which were close to environmental concentrations. The findings indicate that strobilurin fungicides are very toxic to D. magna and they are sufficient to cause harm to D. magna at environmentally relevant concentrations. [ABSTRACT FROM AUTHOR]

We report here an investigation of the mechanisms contributing to the divergent sensitivity toward the triazole fungicide difenoconazole of zebrafish ( Danio reio ) during different life stages. Adult and embryonic zebrafish were exposed to three different concentrations of difenoconazole (0.01, 0.5 and 1.0 mg/L). The death rate, bioaccumulation of difenoconazole, oxidative stress parameters and transcription of related genes were tested at 4 and 8 days post-exposure (dpe). The death rate for adult zebrafish was much higher than that of the embryos at an exposure concentration of 1.0 mg/L at both 4 and 8 dpe. The concentrations of difenoconazole in both the embryos and adult fish were similar, except for the group exposed to 0.01 mg/L difenoconazole. A decrease in antioxidant enzyme activities was observed in both the embryos and the livers of adult fish after exposure to difenoconazole. Significant lipid peroxidation was found in the livers of adult fish in all exposure groups at 8 dpe, but was not observed in the treated embryos. The gene transcription response of the embryos toward difenoconazole was different from that in the livers of adult fish at 4 dpe. At 8 dpe, the modification in the transcription of the tested genes in the embryos and adult fish was similar, except for the genes related to the synthesis of sterols. [ABSTRACT FROM AUTHOR]

An enantioselective method was developed for the simultaneous detection of five chiral fungicides in soil, including fenbuconazole ( 1), tetraconazole ( 2), nuarimol ( 3), triticonazole ( 4), and simeconazole ( 5) by LC-MS/MS on a chiral stationary phase of cellulose tris-(3-chloro-4-methylphenylcarbamate) with a gradient elution. A new multifunctional filter was designed to simplify the QuEChERS (where QuEChERS is quick, easy, cheap, effective, rugged, and safe) method by simultaneous cleanup and filtration when the sample extracts were directly passed through it. Good linearities ( R2 > 0.9980) were obtained in the range 0.005-2.5 mg/L, and the recovery rates were 77.4-103.6% with RSDs of 0.7-12.2% for intraday precision and 1.2-11.0% for interday precision. The LODs and LOQs for all enantiomers were in the range 0.1-0.2 and 0.25-0.5 μg/kg, respectively. The analysis of the incubated soil suggests that this method is reliable and practical for the stereoselective detection of chiral fungicides. [ABSTRACT FROM AUTHOR]

Thifluzamide is a fungicide widely used to control crop diseases, and it therefore constitutes a hazard to the environment. In this study, zebrafish were selected to assess the aquatic toxicity of thifluzamide. The acute and development toxicity of thifluzamide to embryos, larvae, and adult zebrafish were measured and the corresponding 96 h-LC 50 values were as follows: adult fish (4.19 mg/L)