固相萃取-高效液相色谱法检测上海青(Brassica chinensis L.)中鱼藤酮的残留动态

目的]建立固相萃取-高效液相色谱-紫外(SPE-HPLC-UV)检测上海青中鱼藤酮的分析方法,对上海青中鱼藤酮的含量进行动态分析.方法]样品先经乙腈提取,随后在乙腈提取液中加入氯化钠,盐析后过Florisil固相萃取柱富集净化,再用正己烷-乙醚(体积比3∶7)洗脱,最后以乙腈-水(体积比6∶4)为流动相,在290 nm下用高效液相色谱检测分析上海青中鱼藤酮的含量.结果]该方法稳定可靠,检测物在0.05～10 mg/L范围内线性关系良好.在0.5～5 mg/kg范围内,平均加标回收率为85.9％～86.3％,检出限为0.05 mg/kg.田间推荐剂量和2倍推荐剂量分别施药,鱼藤酮在上海青中的原始沉积量分别为6.26、18.34 mg/kg.结论]该化合物在田间降解速率快,在上海青中的半衰期分别为11.2、11.1h.

Residual Dynamics of Rotenone in Greengrocery by Solid-phase Extraction High Performance Liquid Chromatography-UV Detection

Aims] An analytical method for residual dynamics of rotenone in greengrocery by solid-phase extraction(SPE) and high performance liquid chromatography(HPLC)-UV detection was described.Methods] The sample was extracted by acetonitrile,salted out by adding sodium chloride,and cleaned with Florisil SPE using n-hexane-ethyl ether(3∶7,by vol) as eluents to provide adequate recovery of rotenone.The detection of rotenone was then carried out by HPLC-UV at 290 nm with acetonitrile and water(6∶4,by vol) as the mobile phase.Results] The method was accurate,specific and sensitive,and had good linear correlations at the concentration range of 0.05-10 mg/L.The average recoveries and the relative standard deviation ranged from 85.9-86.3% at concentration range of 0.5-5 mg/kg.The limits of detection(LOD) of rotenone were 0.05 mg/kg.When greengrocery was treated with rotenone 2.5% EC at recommended dose and 2 times recommended dose,the original residues rotenone in greengrocery were 6.26 and 18.34 mg/kg.Conclusions] The compound degraded fast in the field.The half-life of rotenone in greengrocery was 11.2 and 11.1 h.