高效液相色谱法测定稻田样品中喹啉铜残留

采用高效液相色谱仪,建立了喹啉铜在稻田水、稻田土壤、水稻植株、稻秆、谷壳和糙米中残留量的检测方法。稻田水、水稻植株、稻秆、谷壳和糙米用乙腈和1 mol/L的盐酸提取,土壤用乙腈和2 mol/L的氢氧化钠提取。稻田水无需净化,其余样品用正己烷和乙腈净化后,采用带有紫外检测器的高效液相色谱仪测定,流动相为V(磷酸盐缓冲液)∶V(乙腈)=60∶40,流速0.8 m L/min,紫外检测波长为250 nm。结果表明:在0.05~5 mg/L范围内,喹啉铜质量浓度与其相对应的色谱峰面积之间呈良好的线性关系,线性方程为y=231.55x-15.064,决定系数(R2)为0.998 5,达极显著水平。在0.05~1 mg/kg添加水平下,稻田水、稻田土壤、水稻植株、稻秆、谷壳和糙米中喹啉铜的平均回收率在83%~103%之间,相对标准偏差(RSD,n=5)在1.5%~6.6%之间。该方法的前处理过程较简单,且准确度、精密度和灵敏度均符合农药残留分析的技术要求。

Determination of oxine-copper residue in paddy field samples by high performance liquid chromatography

The residue analysis method of oxine-copper in paddy water,paddy soil, rice plants, paddy rice straw, rice husk, and coarse rice was development based on high performance liquid chromatography detection. Paddy water, rice plants, paddy rice straw, rice husk, and coarse rice were extracted with acetonitrile and hydrochloric acid(1 mol/L); paddy soil were extracted with acetonitrile and sodium hydroxide(2 mol/L). Paddy water was ready for injection after filtration, while the rest sample extracts were cleaned up with hexane/acetonitrile, and determined by HPLC equipped with UV detector. PBS-acetonitrile(60:40, V/V) was used as mobile phase at a flow rate of 0.8 mL/min, and ultraviolet absorption wavelength was set at 250 nm for UV detector. With the concentration range of 0.05-5 mg/L, there was a good linear relationship between the concentration of oxine-copper with the corresponding chromatographic peak area, the linear equation was y=231.55x-15.064, and the determination coefficient(R²) which reached the significant level was 0.998 5. With fortified levels of 0.05-1 mg/kg, the average recoveries ranged from 83% to 103%, and with relative standard deviation(RSD, n=5) of 1.5%-6.6%. Pre-treatment process of the method was relatively simple, and the sensitivity and accuracy of the method meet with the technical requirements for the analysis of pesticide residues.