The Dissipation Dynamics And Residual Behavior Of Pesticides In Panax Notoginmng And Soils

RADIX ET RHIZOME NOTOGINSENG(Radix notoginseng(Burk.)F.H. Chen)is one of the rarest crude drugs in our traditional Chinese crude drugs.It can cure traumatism and enrich blood.Recently,more and more functions have been found,for example,it can lower blood pressure,cure angina pectoris,coronary heart disease,and miocardial infarction.Now,the demand of Radix notoginseng is increasing rapidly.To protect Radix notoginseng from diseases and insects attacking, many kinds of pesticides are used.The studies were to examine the dissipation dynamics and residual behaviors of pesticides in Radix notoginseng and soil in WenShan County of Yunnan Province,and provide scientific data for formulating the safe application standard of pesticides in Radix notoginseng.The research detected thirty-three kinds of pesticides that included ten kinds of organchlorine pesticides(α-BHC,β-BHC,γ-BHC,δ-BHC,P,P′-DDT,O,P′-DDT, P,P′-DDD,P,P′-DDE,P,P′-DDD,PCNB,Aldrin),eleven kinds of organophosphorous pesticides(dichlorvos,methamidophos,acephate,diazinon,dimethoate,chlorpyrifos, malathion,parathion,quinalphos,methidathion,ethion),five kinds of pyrethroid pesticides(fenpropathrin,permethrin,cypermethrin,fenvalerate,deltamethrin), six kinds of carbamate pesticides(metolcarb,isoprocarb,fenobucarb,carbofuran, pirimicarb,carbaryl)and carbendazim etc.The results showed that the residues of BHC and DDT in biennial Radix notoginseng soil were 0.006-0.013 mg/kg and 0.013-0.078 mg/kg,and in reaped Radix notoginseng(triennium)were 0.027-0.134 mg/kg and 0.038-0.137 mg/kg that were all below the maximum residue limits of Chinese Pharmacopoeia.The residues of permethrin and cypermethrin were 0.26-2.20 mg/kg.0.155-1.250 mg/kg in biennial Radix notoginseng soil,and 0.01-0.66 mg/kg. 0.040-0.375 mg/kg in annual and triennium Radix notoginseng soils.Residues of permethrin and cypermethrin in Radix notoginseng were 0.04-0.22mg/kg. 0.040-0.125 mg/kg respectively.Residues of permethrin and cypermethrin in biennial Radix notoginseng soil were much more than annual and triennium soils.Carbamate and organophosphorus pesticides were not detected in Radix notoginseng and soils.The residues of carbendazim were 2.94-9.32 mg/kg in pedicel and leaf of Radix notoginseng,3.98-4.68 mg/kg in root,and 0.06-0.14 mg/kg in soils.The residue of carbendazim in Radix notoginseng is much more than in soils.The permethrin and cypermethrin degradation experiments at 20℃.30℃indicated that the degradation is more quickly at a higher temperature.In soil,the half life of permethrin and cypermethrin were 23.98 d(30℃).32.08 d(20℃)and 26.96 d(30℃).31.22d(20℃)respectively.