| Recently, lot of highly toxic pesticide have been replaced by pyrethroids because of it’s low toxicity, broad-spectrum, high biological activity, environ-mental compatibility and other features, and its widely used in agricultural production and household pesticides. Recently studies have found that pyrethroid pesticide residues have role of endocrine disruption,and the United States environmental protection (EPA) have set it as one of the suspicious substance, therefore it is needed to detect it’s residues.Chinese Pharmacopoeia start to determination the residues of cypermethrin,deltamethrin and fenvalerate’s in Chinese medicinal herbs in2005edition, which fully shows that the pyrethroid play an important role in pest prevention in Chinese herbal medicine. But the pre-treatment methods used in the Pharmacopoeia requires large amounts of organic solvents, times and its not good for health especially. it is belong to the traditional pre-treatment methods,need to be further improved. Solid phase micro-extraction (SPME) technology just can make up for the above disadvantages, set extraction, concentration, the sample at an organic whole, and simple device, the price is low, SPME can be coupled easily to gas chromatography (GC),high-performance liquid chromatography (HPLC),capillary electrophoreses (CE) and so on, and do not need special equipment. Although there is lots of literatures reported about detect pesticide residues using SPME technology in water, but its rarely found determination in Chinese herbal medicine, and didn’t seen in domestic.It is the first time to use SPME technology in derectly pyrethroids resedue detaction in chinese herbal, acetone extraction assisted with ultrasonic, headspace-solid phase microextraction-gas chromatography-electron capture detector (HS-of SPME-GC-ECD) analysis methods in this study.The pyrethroids pesticide residues were detected in some of the frequently used Chinese herbal medicine (including flowers, leafy, root, whole plant). The results shows that all recoveries of the method ranged form70%to110%.The precision of this methods expressed by the RSD are below10%, the LOD for the method reached0.02mg/kg.Compared the method in this paper with Pharmacopoeia and traditional methods,the prior one can effectively reduce the interference of the herbs matrix, its simple and fast,the amount of the medicinal are small and almost solvents-free, and its detection limit, precision and accuracy are almost as same as Pharmacopoeia or even better.The residue limits of this methodthan can achieve the requirements ten times less than the prescribed in the United States Pharmacopoeia. In this study, to extend the applicability of the technology, we detection more than a dozen herbs like Panax ginseng, Glycirrhiza glabra, and radix astragali et al. There was no significant difference of spiked recoveries in various herbs. But for some individual medicinal plants such as Cortex Phellodendri and Epimedium are not successfully analysis,point out the pre-treatment method need to be further improved. |
