Analysis On The Enrichment And Precipitation Characteristics Of Trace Element In Leaf Of Chinese Holly By Inductively Coupled Plasma Mass Spectrometry

Leaf of Chinese Holly has many active components such as saponin.And it has been used in China asweight loss and hypertension.At present,the research report that study on heavy metal element and trace elements in Leaf of Chinese Holly is not comprehensive.In this paper,trace elements/(rare earth elements)and the dissolution characteristics in Leaf of Chinese Holly were studied by inductively coupled plasma mass spectrometry.The main contents of dissertation are listed as follows:(1)A novel method has been developed for simultaneous determination of trace elements(Pb,Cd,As,Cr,Ni,Cu)by ICP-MS.The effects of wet digestion,microwave digestion and sealed high pressure digestion on the experimental results were studied.And the method was tested using national standard substance(GBW10016).The results show that the sealed high pressure digestion demonstrated thorough digestion,high safety,low blank values,low coast,convenient operation,accurate,high precision and can be used for simultaneous treatment of large quantities of samples,so which was selected as the sample pretreatment method.The results showed that the metallic element exceeded the standard.Especially the lead,comparing with national limit standard that the over standard rate is 15%.Therefore,it is necessary to strengthen the monitoring for heavy metal in Leaf of Chinese Holly.(2)A new method has been developed for the determination of sixteen rare earth elements in Leaf of Chinese Holly by ICP-MS.The sample was digested by HN03+H202,and 103Rh was selected as the internal standard element to eliminate matrix interference and ammonia was used as dynamic reaction gas to eliminate mass spectroscopic interference,then the experimental were optimized The results showed that the detection limits were in the range of 0.1~19.Ong/L,the correlation coefficient was more than 0.999.This method was tested using national standard substance(GBW10050 and GBW10023)and the results are in good agreement with the recommended values.The results show this method is suitable for rapid determination of rare earth elements in Leaf of Chinese Holly with good precision and high accuracy.The higher chemical element of Sc,Y,La,Ce,Pr,Nd in the in the samples of Leaf of Chinese Holly.But the content of samples varies from region to region,and experiment shows that Leaf of Chinese Holly has more security(3)The dissolution characteristics in Leaf of Chinese Holly were also studied.The results showed that the dissolution rate of Na is the highest that Among the 13 kinds of elements,and the dissolution rates of K,Ni,Cu,As,Fe,Ca and Cr are low.The dissolution rate of elements along with the increasing of temperature,and the change of the dissolution rate decreased between 90 and 100 aC.The transfer rate of elements were increased when brewing time in range of 10-30 min,and the upward trends slowed down after 50 min.When the brewing temperature is 90 ?,it was found that the levels of 13 kinds of elements were significant decreased of brewed time.With respect to the recommol/lended daily allowance,drinking Leaf of Chinese Holly do not pose significant risk to human health.