Study on determination of thifluzamide residues in rice

A method for determination of thifluzamide residues in paddy soil/water,rice straw and plant,rice hull/rice was developed.Thifluzamide residue in water was separated,purified and pre-concentrated by C18 soild phase extraction(SPE);Soil,straw,rice,rice hull and plant were extracted with acetone-petroleum ether mixture(1∶1,V/V) and petroleum ether,purified with a silica gel column.The all samples were analysed by gas chromatography with electronic capture detector(GC-ECD).The correlation coefficient(r) of this method was 0.999 1,and the calibration curve was linear in the range of 0.005-10 mg/L.The detection limit in water was 0.005 mg/L and the detection limits in paddy soil,rice straw,plant,rice hull and rice were all 0.004 mg/kg.When the spiked levels of 0.05,0.5 and 1 mg/L in water and the spiked levels of 0.04,0.4 and 4 mg/kg in paddy soil,rice straw,green plant,rice hull and rice,the spiked recoveries of thifluzamide in all samples ranged from 86.6% to 106.2%,with relative standard deviations(RSDs) from 1.3% to 9.9%.