HPLC测定植物性农药——0.25%乌头总碱乳油中的乌头类生物碱

 选择十八烷基键合相柱 ,以甲醇 水 氯仿 三乙胺 (体积比为 6 8∶32∶2∶0 1)混合溶液为流动相 ,用高效液相法测定了一种植物性农药 0 2 5 %乌头总碱乳油中的乌头生物碱。实验结果表明中乌头碱、乌头碱及次乌头碱与其他杂质能够得到很好的分离。以安宫黄体酮作内标物 ,用峰面积比测定各生物碱含量 ,在其线性范围内分析结果准确 ,回收率高 (>92 % ) ,重现性好 (RSD <3 2 % ) 。

Determination of Aconitine Alkaloids in a Pesticide0.25%Aconitine Alkaloids Mixed with Emulsion by HighPerformance Liquid Chromatography

The raw root of Aconitum, an important Chinese traditional medicine, contains some very toxic alkaloids such as aconitine, mesaconitine and hypaconitine etc. They are usually processed to lower the alkaloid content before used as a drug. The extract of crude drug (aconite) can be made into a plant pesticide by means of mixing with some emulsion. In order to evaluate the quality of the pesticide, we developed a rapid, specific and precise method using high performance liquid chromatography (HPLC) for the separation and quantitation of the alkaloids in the aconite extract and the mixed products (the aconite extract is mixed with emulsion). Before the determination by HPLC, the sample must be acidified with 2% (mass percentage) HCl at first. Extract the acid liquid with CHCl3. Alkalize the extract with ammonia, and add a little of 0.1 mol/L NaHCO3 and 0.1 mol/L Na2CO3 till pH 9. Extract it with CHCl3. Evaporate the extract and add a certain amount of methanol. Add the internal standard into the sample. Inject the combined sample solution onto a column of chemically bonded octadecylsilane phase and develop the chromatogram with MeOH-H2O-CHCl3-triethylamine (68:32:2:0.1, volume ratio). Aconitine, mesaconitine, hypaconitine and medroxyprogesteroni acetas (internal standard) were on base line separated. Quantify the alkaloids by peak area ratio (aconitine alkaloids vs internal standard). This method has high recovery (> 92%) and good reproducibility (RSD < 3.2%).