Determination and speciation analysis of the microelements in Rauvolfia by ICP-MS

This research focuses on the determination and speciation analysis of the microelements of Zn,Mn,Pb,Fe,Cu,Cr,As,Ni and Cd in Rauvolfia by the Inductively Coupled Plasma-Mass Spectrometry( ICP-MS). The samples are extracted with deionized water,digested by HNO3-H2O2 electrical furnace heating,and determined by ICP-MS. The precision of the determination is validated by tea leaves GBW10016. The results show that the contents of the microelements are Zn Mn Pb Fe Cu Cr As Ni Cd,while the aqueous extraction reveals Zn Mn As Ni Cr Pb Cd,and Fe and Cu are not detected. The residual form in the contents of each element is 0. 014—9. 643μg / g,the elements of Zn,Mn,Cr,As and Ni are both in a soluble organic state and a soluble inorganic state in the water extract,the ratio of the organic state to the inorganic state is in the range of 28. 12% —264. 55%,and the organic states of Zn,Cr and Ni are greater than those of the inorganic states; their ratio is greater than 166. 67% respectively; the adsorption ratio of the suspension state is about 7. 69% —125%; nine kinds of microelements in Rauwolfia are found to comprise a complex system with the characteristics of the coexistence of various states. Keywords: Rauvolfia; ICP-MS; microelements; speciation analysis