水稻田样品中噻呋酰胺残留检测方法研究

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%。

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%.