Farmacognosia y Productos Naturales, Universidad de la Republica, Montevideo, Uruguay.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2010 Feb;27(2):206-11. doi: 10.1080/19440040903296246.
Different extraction procedures and clean-up methods were compared in order to develop a sample preparation procedure for the multi-residue analysis of six post-emergence herbicides (metsulfuron methyl, bensulfuron methyl, pyrazosulfuron ethyl, bentazone, bispyribac sodium and cyhalofop butyl) in rice grains followed by liquid chromatography-diode array detection (LC-DAD). Optimum results were obtained dispersing milled rice grain in water, followed by the addition of 1% acetic acid in acetonitrile, MgSO(4) and sodium acetate as a modification of the quick, easy, cheap, effective, rugged and safe (QuEChERS) method but no primary and secondary amine (PSA) sorbent was added due to the acidic nature of the herbicides. The method was further expanded to other post-emergence herbicides (quinclorac, clomazone and propanil). Except for quinclorac, which cannot be analysed with this method, the recoveries of the other eight herbicides were in the range 73-111%, with relative standard deviations lower than 12%. Limits of detection (LODs) ranged from 0.03 to 0.08 mg kg(-1). A single analyst can extract twelve samples in 4 h. The method presented here allows the simultaneous residue determination of the most common post-emergence herbicides employed in cultivating rice. It is simple, rapid, sensitive, and can be applied routinely to polished rice grain herbicide residue analysis.
为了开发一种用于大米中六种后茬除草剂（甲磺隆甲基、苄磺隆甲基、吡唑磺隆乙基、苯达松、双吡氟草胺和氰氟草酯丁基）多残留分析的样品制备方法，比较了不同的提取程序和净化方法，随后采用液相色谱-二极管阵列检测（LC-DAD）。最佳结果是将研磨的米粒分散在水中，然后加入 1%乙酸的乙腈、MgSO(4)和醋酸钠，这是对快速、简便、廉价、有效、坚固和安全（QuEChERS）方法的改进，但由于除草剂的酸性性质，没有添加初级和次级胺（PSA）吸附剂。该方法进一步扩展到其他后茬除草剂（氯喹酸、克草酮和丙草胺）。除了氯喹酸，该方法无法分析外，其他八种除草剂的回收率在 73-111%之间，相对标准偏差低于 12%。检测限（LOD）范围为 0.03-0.08mgkg(-1)。单个分析员可以在 4 小时内提取 12 个样品。本文提出的方法允许同时测定用于种植水稻的最常见的后茬除草剂的残留量。它简单、快速、灵敏，可常规应用于精米中除草剂残留分析。
