设计并制作了结合基质固相分散萃取与索氏萃取于一体的萃取器,将粉碎的中药样品与弗罗里硅土充分研磨分散与一均匀的混合物.先在萃取器的萃取柱中放入一定量的无水硫酸钠、弗罗里硅土及石墨化碳黑,将样品混合物和无水硫酸钠一起加入柱中.用丙酮-乙酸乙酯(1+4)混合溶剂作萃取剂,在加热条件下萃取20 min,经萃取,被测的4种有机磷农药完成了分离净化,所得萃取液在40 ℃水浴中加热蒸发至近干,用1.0 mL丙酮溶解残渣,供气相色谱法测其中4种农药.测定中采用火焰光度检测器.4种农药检出限(3S/N)为0.006~0.008 mg·kg-1之间.方法的回收率在75.1%~97.8%之间,测定值的相对标准偏差(n=5)在2.9%~13.9%之间.

An extractor combining the matrix solid-phase dispersion (MSD) and Soxhlet′s extraction (SXE) was designed. Powdered medicine sample was pulverized and dispersed with fluorisil to give a homogeneous mixture,which was added to the extraction column together with some anhydrous sodium sulfate. Definite amounts of anhydrous Na2SO4,fluorisil and graphitized carbon black were previously added to the column before the addition of the sample mixture. A mixed solvent of acetone and ethylacetate (1+4) was used as extractant,and the extraction performed under heating for 20 min. Separation and purification of the 4 organophosphorus pesticides were fulfilled in this process. The extract was evaporated to near dryness in a water bath at 40 ℃. One mL of acetone was added to taken up the residue and the solution was used for GC analysis. Flame photometric detection was used in the determination. Detection limits (3S/N) found were ranged from 0.006-0.008 mg·kg-1 for the 4 pesticides. Values of recovery found for the 4 pesticides were in the range from 75.1%-97.8% and values of RSD′s (n=5) were in the range of 2.9% to 13.9%.