Research On The Residues Of Plant Regulators And Fungicides In Rhizome Traditional Chinese Medicines

Traditional Chinese medicine（TCM）is one of the significant treasures of people’s disease prevention and health care,which has currently become an indispensable stuff in people’s daily life.However,most TCMs are obtained by planting owing to the limited wild resources,some of them lack professional management in the process of changing from wild into planting,which results in the nonstandard and unreasonable use of pesticides.Additionally,coupled with the comprehensive influence of environmental factors such as air,water and soil,TCMs are more likely to be polluted.Thus,this paper mainly explores and studies the residues of fungicides and plant growth regulators in rhizome TCMs,and the main contents of the dissertation are as follows:1.A method was developed for the determination of 40 plant growth regulators and fungicides in rhizome TCMs by liquid chromatography-tandem mass spectrometry（LC-MS/MS）,and the liquid conditions,extraction and purification conditions were optimized.The results denoted that the linearity of the 40 plant growth regulators and fungicides was good in their respective ranges,with the correlation coefficients R~2greater than 0.99.The average recoveries ranged from 80%to 113%,the relative standard deviations is between 0.37%and 10.89%the limits of quantification ranged from 0.05～250.0μg/kg,which could finally meet the detection requirements.2.The residues of 40 kinds of plant growth regulators and fungicides in 9 kinds of rhizome TCMs were successfully determined,and the dietary exposure risk of contaminated medicinal materials was assessed by hazard quotient（HQ）and health risk index（HI）methods.Lastly,25 compounds were detected in 81 samples.Among them,the residue of triazole fungicide was the highest,ranging from 2.13～726.16μg/kg.Ginseng,Panax notoginseng and American ginseng are the most serious residues among9 kinds of rhizome TCMs.The risk assessment results of different rhizome TCMs finally show that the values of HQ and HI are far less than 1,which indicates that the plant growth regulators and fungicides remaining in rhizome TCMs are not significantly harmful to consumers’health.3.The residues of 40 plant growth regulators and fungicides in ginseng roots,stems and leaves and rhizosphere soil were well studied.The final results suggested that10 kinds of target compounds were detected in soil,9 kinds of target compounds in roots and 10 kinds of target compounds in stems and leaves.By Spearman’s rank correlation analysis,it was discovered that the correlation coefficient r of the concentrations of most compounds in ginseng roots except choline chloride and chlorocholine chloride was greater than 0.5,showing a significant positive correlation,which denoted that the compounds are of relatively similar origin.4.The influence of different drying methods on the residual amount of target compounds was further explored and discussed.The fresh ginseng roots were treated by three drying methods,namely sun drying,freeze drying and oven dry.The content change of target compounds during processing was analyzed in combination with residual amount,processing factors and change rate.Ultimately,it was concluded that the optimal drying method of ginseng was sun drying.