ANALYSIS Of PESTICIDE RESIDUES In GINSENG And AMERICAN GINSENG

Just like the old mysterious and splendid Chinese culture, which is more than5,000years, Ginseng, one of the most important Chinese medicinal herbs, enjoy the equivalent reputation in China, even in the world. There is no doubt that the increase in demand caused the rise in prices.At the same time the growth cycle of Ginseng is long.A demanding cooler climates is essential for the quality of Ginseng. By popular demand, in the last decades Ginseng has been successfully planted artificially. However the deadly ignorance of environment and the excessive use of chemical pesticides has also resulted in residues problems in Ginseng. In view of the problem, effective measures should be taken before things get worse, so it is very necessary to develop a high-performace, rapid, accurate and practical method for determination of chemical pesticides.The research has explored eight kinds of efficient analytical methods in some traditional pesticides including Organochlorine pesticides、Organophosphorus pesticides、Pyrethroid pesticides and some new-used pesticides such as Fluazinam、 Azoxystrobin etc. The main contents are as follows:1. A gas chromatography method(GC-ECD) has been developed for determining ten kinds of Organochlorine pesticides residues in Ginseng and American Ginseng. The pesticide was extracted with petroleum ether, cleaned up by sulphuric acid. The fortified recoveries and relative standard deviation (RSD) were84.0%to107.2%and1.5%to7.1%.The limit of quantification was0.01mg/kg.2. A gas chromatography method(GC-ECD) has been developed for determining six kinds of Pyrethroid pesticides residues in Ginseng and American Ginseng. Pesticides were extracted with petroleum ether, cleaned up by column chromatography (florisil:neutral alumina=7:5,m/m).The fortified recoveries and relative standard deviation(RSD) were33.2%to109.5%and1.2%to6.3%.3. A gas chromatography method(GC-FPD) has been developed for determining eighteen kinds of Organophosphorus pesticides residues in Ginseng and American Ginseng. The pesticide was extracted with acetone, cleaned up by column chromatography (Celete545:Activated Carbon=4:1,m/m).The fortified recoveries and relative standard deviation (RSD) were82.0%to104.6%and0.6%to4.2%.4. A gas chromatography method(GC-ECD)has been developed for determining fluazinam residues in Ginseng and American Ginseng. The residues were extracted with acetonitrile and water assisted by ultrasonic, cleaned up with dichloromethane by the aid of liquid-liquid partition. Pesticide standards were fortified into ginseng samples at3levels (0.05,0.1and1.0mg/kg). The results showed average recoveries were89.5-96.4%with relative standard deviations2.3～4.3%. The limit of quantification (LOQ) was0.05mg/kg.5. A gas chromatography method(GC-ECD) has been developed for determining azoxystrobin residues in Ginseng and American Ginseng. The residues were extracted with acetonitrile and water assisted by ultrasonic, cleaned up with florisil-neutral alumina-activated charcoal (5:3:0.15,m/m/m) mixed column and dichloromethane by means of liquid-liquid partition. The results showed average recoveries were82.1-97.5%with relative standard deviations1.5-6.1%. The limit of quantification (LOQ) was0.01mg/kg.6. A gas chromatography method(ECD) has been developed for determining prochloraz residues in Ginseng and American Ginseng. Prochloraz was extracted with acetone and hydrochloric acid, hydrolyzed by pyridine hydrochloride, cleaned up by sulphuric acid. The residue of prochloraz can be calculated with2,4,6-trichlorophenol. The fortified recoveries and relative standard deviation(RSD) were98.9%to103.4%and1.0%to2.9%. The standard curve of prochloraz was linear in the range of0.005-2mg/L (R2=0.9996).The limit of quantification was0.005mg/kg.7. A reversed phase high performance liquid chromatography (HPLC) method has been developed for determining carbendazim residues in Ginseng and American Ginseng. Carbendazim was extracted with acetone, cleaned up by column chromatography (florisil:neutral alumina=7:4,m/m) and determined by liquid-liquid partition. HPLC equipped with UV detector. The fortified recoveries and relative standard deviation(RSD) were80.4%to88.2%and5.3%to6.5%. The standard curve of carbendazim was linear in the range of0.05-10mg/L (R2=0.9994).The limit of quantification was0.05mg/kg.8. A gas chromatography method (FPD-S) has been developed for determining mancozeb residues in Ginseng and American Ginseng. Add mancozeb and HCl/SnCl2into10mL bottle, react at80℃for120minutes and create carbon disulfide. The residue of mancozeb can be calculated with carbon disulfide. The fortified recoveries and relative standard deviation(RSD) were90.8%to99.9%and2.4%to7.0%. The limit of quantification was0.2mg/kg.