Needham L, Paschal D, Rollen Z J, Liddle J, Bayse D
J Chromatogr Sci. 1979 Feb;17(2):87-90. doi: 10.1093/chromsci/17.2.87.
A sensitive and selective method is described for the quantitative determination of paraquat in marijuana. Paraquat is extracted from finely ground plant material with hydrochloric acid with sonification, and the resulting acidic solution is extracted with chloroform:isopropanol (9:1) and evaporated to dryness. The residue is reconstituted with aqueous phosphate buffer pH 7.0; the solution is passed through a C-18 SEP-PAK TM and is analyzed with high performance liquid chromatography, using a reversed-phase column and an "ion pairing" reagent in the mobile phase. The recovery of paraquat in laboratory-spiked material varied from 90-97%. Results obtained with confiscated, field-sprayed marijuana by the procedure described were in excellent agreement with those obtained with a well-established ultraviolet procedure. The calculated limit of detection with this method is 2 ng of paraquat.
描述了一种灵敏且具选择性的方法，用于定量测定大麻中的百草枯。将精细研磨的植物材料用盐酸通过超声处理进行萃取，所得酸性溶液用氯仿：异丙醇（9:1）萃取并蒸发至干。残渣用pH 7.0的磷酸盐缓冲水溶液复溶；溶液通过C-18 SEP-PAK TM柱，并采用高效液相色谱法进行分析，流动相中使用反相柱和“离子对”试剂。实验室加标材料中百草枯的回收率在90%至97%之间。通过所述方法对查获的、现场喷洒过的大麻进行检测，所得结果与采用成熟的紫外检测方法所得结果高度一致。该方法计算得出的百草枯检测限为2纳克。
