Study On Content Analysis,Speciation Analysis And Risk Assessment Of Heavy Metals In Six Common Chinese Medicinal Materials

Objectives:1)In this study,the residual levels of heavy metals in 6 kinds of traditional Chinese medicine in Chinese Pharmacopoeia will be determined,the health risks of heavy metals will be evaluated,and the residual rules of heavy metals in different commodity specifications of Forsythiae fructus?Qingqiao and Laoqiao?will be revealed.2)On the basis of previous studies,the occurrence forms of arsenic and mercury in Sepiae Endoconcha,Bungarus Parvus and Eupolyphaga Steleophaga will be determined.In addition,the breeding environment samples of Bungarus Parvus and Eupolyphaga Steleophaga will be analyzed,and the possible pollution sources will be discussed.Methods:1)Microwave digestion-inductively coupled plasma mass spectrometry?ICP-MS?was used to determine the contents of heavy metals in six kinds of traditional Chinese medicine,and the risk assessment model of the Environmental Protection Agency of the United States?USEPA?was used to evaluate the health risks of the six kinds of traditional Chinese medicine with average daily intake?ADD?and hazard quotient?HQ?as parameters.Multivariate statistical method and principal component analysis?PCA?)were used to analyze the difference,correlation and comprehensive evaluation of heavy metal elements in Qingqiao and Laoqiao.2)In Sepiae Endoconcha samples,the arsenic species were extracted by ultrasonic extraction with hot water,and 6kinds of arsenic species were determined by high performance liquid chromatography-inductively coupled plasma mass spectrometry?HPLC-ICP-MS?.3)In Bungarus Parvus samples,the mercury speciation were extracted by ultrasonic extraction with the special extract solution?L-cysteine,2-mercaptoethanol,hydrochloric acid?.Three kinds of mercury in Bungarus Parvus samples and six kinds of arsenic in Eupolyphaga Steleophaga samples were determined by HPLC-ICP-MS.The USEPA risk assessment model was used to assess the health risk of highly toxic forms?inorganic arsenic?iAs?and methylmercury?MeHg??in Bungarus Parvus and Eupolyphaga Steleophaga samples,taking the recommended doses of iAs and MeHg as parameters and ADD and HQ as risk assessment indicators.Results:1)The heavy metal residues of lead?Pb?,cadmium?Cd?,arsenic?As?,mercury?Hg?,copper?Cu?and chromium?Cr?in 35batches of Codonopsis radix,16 batches of Glycyrrhizae radix et rhizoma and 89 batches of Forsythiae fructus?including 60 batches of Qingqiao and 29 batches of Laoqiao?not exceed the limits of standard of the 2015 edition of Chinese Pharmacopoeia and the Green Industry Standard for Foreign Trade of Medicinal plants and preparations?WM-T2-2004?.However,32 batches of Sepiae endoconcha,20 batches of Bungarus parvus and 86 batches of Eupolyphaga steleophaga exceed the limits of standard of the2015 edition of Chinese Pharmacopoeia.Bungarus parvus exceeded the standard seriously,and 75.00%of Bungarus parvus samples were unqualified.The overall over-standard rate of Pb,As and Cu elements in Eupolyphaga steleophaga samples reached 56.98%.Although the over-standard rate of As in Eupolyphaga steleophaga samples was not high,the overall As residue was close to the limit of standard.The results of risk assessment showed that the HQ values of Cr and As in Codonopsis radix were greater than 1,indicating that there were health risks in Codonopsis radix samples.The HQ values of Cr,As,Cd,Hg and Pb in Sepiae endoconcha were more than 1,and the highest HQ of As was 5.004,followed by 3.541 of Pb,which indicated that the health risk of Sepiae endoconcha was relatively high.In Eupolyphaga steleophaga samples,the HQ values of Cr was 6.286,and the HQ values of As and Pb were both greater than 1,suggesting that Eupolyphaga steleophaga samples also has the health risk.There was little difference in the content of heavy metals in different sources of Forsythiae fructus,but there was significant difference in the content of heavy metals in different commodity specifications of Forsythiae fructus?Qingqiao and Laoqiao?.The content of Pb in Laoqiao was higher than Qingqiao significantly,and the content of Cu in Laoqiao was lower than Qingqiao.The harvest time of Forsythiae fructus was positively correlated with the contents of Pb,Hg and Cd,but negatively correlated with Cu.The principal component PC₁-PC₂ extracted by principal component?PCA?extraction method was used to draw a two-dimensional map of score.89 batches of Qingqiao and Laoqiao were divided into two categories,and the classification results were basically consistent with the original commodity specification information of all Forsythiae fructus samples.2)The total arsenic content?T-As?in 32 batches of Sepiae endoconcha samples was generally high,and the carcinogenic inorganic arsenic?iAs?content in 18.75%of Sepiae endoconcha samples exceeded the limit of iAs in food.The main forms of As in Sepiae endoconcha are arsenobetaine?AsB?,dimethylarsinic acid?DMA?and arsenic acid?As?V??.The determination rate of iAs in Sepiae endoconcha samples is 28%,in which the contents of arsenicus acid?As?III??is up to 103.3?g·kg^-11 and the contents of As?V?is up to 222.4?g·kg^-1.3)The occurrence forms of Hg in Bungarus parvus are MeHg and ionic mercury(Hg²⁺).The highly toxic MeHg forms account for more than 97%of the total Hg forms,and the highest MeHg contents is up to 186.21?g·kg^-1.The content of MeHg in50%of Bungarus parvus samples was higher than 100?g·kg^-1.The occurrence forms of Hg in the feed?Monopterus Albus and Misgurnus anguillicaudatus samples?of 11batches of Bungarus parvus were also MeHg and Hg²⁺.The contents of MeHg accounts for more than 95%of the total contents of mercury speciations in Monopterus Albus samples,and the highest contents is 171.76?g·kg^-1.The contents of MeHg accounted for more than 82%of the total contents of mercury speciations in Misgurnus anguillicaudatus samples,and the highest contents was 79.53?g·kg^-1.No Hg was detected in feeding water samples.The forms of As in Eupolyphaga steleophaga samples were various.As?III?,AsB,DMA,monomethyl arsenic?MMA?and As?V?,were detected in 86 batches of Eupolyphaga steleophaga samples,in which As?V?was the main occurrence form,and arsenocholine?AsC?was detected in 11 batches.In the samples of Eupolyphaga steleophaga,the contents of iAs accounted for 61%-91%of the total arsenic speciations contents,and the contents range was 529.77-1846.14?g·kg^-1.The highest contents of As?III?in iAs was 563.21?g·kg^-1 and the highest content of as?V?in iAs was1314.09?g·kg^-1.The forms of As in the feed?wheat bran?of Eupolyphaga steleophaga samples was also dominated by iAs.The average contents of As?III?was 32.26?g·kg^-1and the average contents of As?V?was 105.46?g·kg^-1 in wheat bran.The results of the study on the water samples from the Eupolyphaga steleophaga culture base showed that the underground water samples contained three kinds of As forms,the contents of As?III?,As?V?and DMA,were 14.40,2.56 and 0.52?g·kg^-1,respectively,and only 2.36?g·kg^-1As?V?,was detected in tap water.The results of iAs and MeHg morphological health risk assessment showed that the maximum HQ value of iAs in Eupolyphaga steleophaga sample was 1.10,indicating that there was a certain health risk of iAs in Eupolyphaga steleophaga.In Bungarus parvus,according to the dosage of 5g and 1.5g,the maximum values of HQ were 0.17 and 0.05 respectively,indicating that the risk of MeHg to human health was lower under the condition of decoction and powder.Conclusions:1)The contents of heavy metals Pb,Cd,As,Hg,Cu and Cr in Codonopsis radix,Glycyrrhizae radix et rhizoma and Forsythiae fructus samples accorded with the limits of standard,but the heavy metals of Sepiae endoconcha,Bungarus parvus and Eupolyphaga steleophaga exceeded the limits of standard.The problem of Hg exceeding the standard was more significant in Bungarus parvus samples.Health risk studies have shown that there are health risks in Codonopsis radix,Sepiae endoconcha and Eupolyphaga steleophaga samples.The high total content of heavy metals does not mean that the health risk is also high,such as Codonopsis radix and Bungarus parvus.The above results also show that the health risk of heavy metal elements in traditional Chinese medicine is more closely related to the dosage and medication method.The results of the contents of heavy metals in Forsythiae fructus showed that there was a significant difference in Pb contents between the two commodity specifications of Forsythiae fructus?Qingqiao and Laoqiao?,suggesting that Forsythiae fructus would enrich more Pb during fruit ripening.2)The total arsenic contents?T-As?in 32 batches of Sepiae Endoconcha samples is generally high.Sepiae Endoconcha samples contain carcinogenic iAs forms,and the contents of iAs in 18.75%Sepiae Endoconcha samples exceeds the limits of standard of iAs in food.The results also showed that the total amount and the speciation of As in the Sepiae Endoconcha was not positive correlated,indicating there are loopholes in the total amount control mode.Especially after the limited amount is up-regulated,it is difficult to supervise the Sepiae Endoconcha with excessive inorganic As content caused by pollution and other factors.3)The strong toxic component MeHg accounts for the majority in Bungarus parvus and its feed?Monopterus Albus and Misgurnus anguillicaudatus?,accounting for more than 97.2%of the total contents of Hg.Studies have shown that the possible source of MeHg in Bungarus parvus is that feed containing MeHg?Monopterus Albus and Misgurnus anguillicaudatus?causes accumulation in breeding snakes,and MeHg is transmitted to young snakes through embryos,resulting in pollution of medicinal materials.The iAs is the main occurrence form of As in Eupolyphaga steleophaga and its feed?wheat bran?.Contaminated feed and groundwater lead to the accumulation of As through the biomagnification effect of the food chain,thus affecting quality and drug safety of Eupolyphaga steleophaga.It is also suggested that source prevention and control should be carried out and culture should be standardized.The study on the health risk of high toxic form shows that there is a health risk in the iAs of Eupolyphaga steleophaga,while the health risk of MeHg in Bungarus parvus is lower,but the long-term accumulation risk should not be ignored.