水稻田样品中噻呋酰胺残留检测方法研究

Study on determination of thifluzamide residues in rice

建立了噻呋酰胺在稻田土壤、稻田水、水稻秸秆、水稻绿色植株、谷壳和糙米中的残留检测方法。稻田水中的噻呋酰胺用LC-18固相萃取小柱分离、净化和富集;稻田土壤、水稻秸秆、谷壳和糙米样品采用V(丙酮)∶V(石油醚)=1∶1超声提取,硅胶柱净化;绿色植株样品用石油醚超声提取,硅胶柱净化。提取净化后的所有样品均采用气相色谱-电子捕获检测器(GC-ECD)测定。结果表明,噻呋酰胺在0.005～10 mg/L范围内线性关系良好,相关系数(r)为0.999 1。其方法检出限分别为:稻田水中0.005 mg/L,土壤、水稻秸秆、绿色稻株、谷壳及糙米中均为0.004 mg/kg。在水样中添加水平为0.05、0.5和1 mg/L及在土壤、秸秆、绿色稻株、谷壳和糙米中添加水平为0.04、0.4和4 mg/kg时,添加回收率均在86.6%～106.2%范围内,相对标准偏差(RSD)为1.3%～9.9%。

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 preconcentrated by C18 solid 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%.