Reserch And Application Of Detection Technology Of Harmful Pollutants In Chinese Herbal Medicine

Chinese herbal medicines(CHMs)play an important role in disease prevention and treatment,and have been widely used in China and abroad.The efficiency and safety of the external harmful residues of CHMs have also attracted worldwide attention.The potential safety hazards of harmful residues have become the main reason for limiting the export of CHMs.Therefore,the research methods and limit standards for the detection of external pollutants need to be more stringent.In this study,two kinds of harmful residues,sulfur dioxide and pesticides,were investigated in CHMs.(1)A nitrogen-assisted distillation-ion chromatography method was developed to rapidly determine the residual amount of sulfur dioxide in CHMs Pre-treatment experimental conditions(distillation rate,nitrogen flow,etc.)and ion chromatographic conditions(chromatographic column,mobile phase)were selected and optimized The limit of quantification is 10 mg/kg The recoveries ranged from 78.0% to 99.4%,and the relative standard deviation was 5.4%,at the spiked level of 20 mg/kg in the representative sample.Using the representative samples of uniflower swisscentaury root,dioscorea bulbifera and Asparagus cochinchinensis,the proposed method was compared with the traditional steam distillation method.The results were comparable,while the proposed method has the advantages of high-throughput and rapid.The method is simple,rapid,sensitive and accurate,which is satisfied with the requirements of domestic and international residue limits.It is verified to be suitable for the detection of sulfur dioxide residues in Chinese herbal medicines.The sulphur dioxide residues in the 342 batches of CHMs were tested and analyzed.(2)A new method based on a QuEChERS extraction followed by the gas chromatog-raphy-tandem mass spectrometry(GC-MS/MS)detection has been developed for the analysis of pesticide residues in CHMs.A series of experimental conditions were optimized: the DB-5MS column was selected,the temperature program was optimized,the mass spectrometry SRM conditions were determined,and a GC-MS/MS database of 470 pesticides was established.The pretreatment conditions of QuEChERS samples for the detection of more than 400 pesticide residues in herbal samples from different sample types were selected and optimized.The limits of quantification(LOQ),recovery and precision of the method were validated.The limits of quantification for these pesticides ranged from 0.006 to 221 ?g/kg.The LOQs are less than 50 ?g/kg for 80% analytes.The LOQs of 60% analytes are less than 10 ?g/kg,for roots and seeds.The analysis time of a single sample instrument didn't exceed 40 min.This method has the advantages of rapid detection and high throughput.It can analyze more than 400 pesticide residues at the same time.The method was applied to monitor pesticide residues in 300 batches CHMsAccording to the analysis of the test results,59 batches of positive samples of sulfur dioxide residues in 342 batches of CHMs were tested.According to the limit of the Chinese Pharmacopoeia(2015 edition),15 batches exceeded the batch,accounting for4.4% of the total sample batches.Among them,the detection rate of roots and mosaics and the average content of samples were higher.Through the analysis of the results of the detection of pesticide residues in 300 batches of CHMs.There are at least one of the 280 batches of pesticide residues.The results suggest that there is a certain degree of sulfur dioxide residues in Chinese herbal medicines and the potential health risks of pesticide residues should be of concern.