Analysis Of Five Special Pesticide Residues In Chinese Herbal Medicines

People have been paying more and more attention to the pesticide residues. It is not only harmful to the health of people, but also affects the quality of traditional Chinese herbal medicines. Therefore, it is really significant to develop a simple, fast, accurate and reliable method for measuring pesticide residues in Chinese herbal medicines. The research has provided five efficient analytical methods of Carbendazim, Mancozeb, Dimehypo, Glyphosate and Prochloraz residues in hundreds of Chinese herbal medicine samples. The main contents are as follows:1. A reversed phase high performance liquid chromatography (HPLC) method has been developed for determining carbendazim residues in Radix Paeoniae, Radix Ophiopogonis, Radix Astragali, Radix Rhizoma, Radix Ginsen Rubra, Rhizoma Bolbostematis, Fructus Corni, Rhizoma Macrocephalae, Radix Scrophulariae, Radix Scutellariae, Flos Lonicerae, Flos Chrysanthemi, Radix Ginseng, Radix Quinquefolii, Rhizoma Coptidis, Radix Tiorrhizae, Rhizoma Smilacis, Rhizoma Dioscoreae, Rhizoma Corydalis, Radix Rubra. Carbendazim was extracted with acetone, cleaned up by column chromatography (florisil:neutral alumina=7:4) and determined by liquid-liquid partition. HPLC equipped with UV detector. The fortified recoveries and relative standard deviation(RSD) were 70.6% to 98.3% and 0.5% to 9.1%. The standard curve of carbendazim was linear in the range of 0.05-10 mg/L (r=0.9994), the limit of quantification was 0.01mg/kg in Radix Scrophulariae and Flos Chrysanthemi, and others were 0.05 mg/kg.2. A gas chromatography method (FPD-S) has been developed for determining mancozeb residues in Radix Ginseng, Radix Quinquefolii, Radix Scrophulariae, Radix Ophiopogonis, Radix Curcumae, Herba Centellae, Rhizoma Lingae, Radix Multiflori, Radix Bupleuri, Rhizoma Smilacis, Rhizoma Bolbostematis, Flos Chrysanthemi, Rhizoma Dioscoreae, Rhizoma Curcumae, Radix Glycyrrhizae, Radix Senticosi, Herba Taraxaci, Rhizoma Coptidis, Radix Sinensis, Radix Tiorrhizae, Radix Ginsen Rubra, Radix Paeoniae. Add mancozeb and HCl/SnCl2 into 10 mL bottle, react at 80℃for 120 minutes and create carbon disulfide. The residue of mancozeb can be calculated with carbon disulfide. The fortified recoveries and relative standard deviation(RSD) were 74.6% to 102.6% and 0.6% to 13.3%. The standard curve of carbendazim was linear in the range of 0.5-10 mg/L (r=0.9984), the limit of quantification was 0.2mg/kg.3. A gas chromatographic method(ECD) has been developed for determining dimehypo residues in Radix Paeoniae, Rhizoma Bolbostematis, Radix Glycyrrhizae, Flos Lonicerae, Flos Chrysanthemi, Radix Ginseng, et al. It can produce nereis toxin under alkaline or aerobic environment. The residue of dimehypo can be calculated with carbon nereis toxin. The fortified recoveries and relative standard deviation(RSD) were 72.6% to 102.8% and 0.5% to 9.6%. The standard curve of carbendazim was linear in the range of 0.5-10 mg/L (r= 0.9998), the limit of quantification was 0.05mg/kg.4. A gas chromatography method(NPD) has been developed for determining glyphosate residues in Radix Paeoniae, Rhizoma Bolbostematis, Rhizoma Smilacis, Rhizoma Dioscoreae, Stigma Croci, Radix Senticosi, Rhizoma Curcumae, Radix Glycyrrhizae, Radix Scrophulariae, Radix Saposhnikoviae, et al. Glyphosate was extracted with acetone, cleaned up by dichloromethane and C18 column, and reacted with TFAA and TFE. The final product can represent glyphosate residue. The fortified recoveries and relative standard deviation(RSD) were 68.7% to 107.7% and 0.4% to 7.8%. The standard curve of carbendazim was linear in the range of 0.05-10 mg/L (r=0.9987), the limit of quantification was 0.05mg/kg.5. A gas chromatography method(ECD) has been developed for determining prochloraz residues in Radix Ginseng, Rhizoma Macrocephalae, Rhizoma Curcumae, Rhizoma Dioscoreae, Fructus Crataegi, Radix Senticosi, Herba Taraxaci, Flos Lonicerae, Radix Saposhnikoviae, et al. Prochloraz was extracted with acetone and hydrochloric acid, hydrolyzed by pyridine hydrochloride, cleaned up by sulphuric acid. The residue of prochloraz can be calculated with 2,4,6-trichlorophenol. The fortified recoveries and relative standard deviation(RSD) were 76.6% to 105.2% and 0.7% to 7.9%. The standard curve of carbendazim was linear in the range of 0.005-2mg/L (r=0.9996), the limit of quantification was 0.005mg/kg.