Applying study of SEC-ICP-MS in speciation analysis of selenium-containing proteins in selenized cordyceps militaris link

It was reported in this paper that soluble protein was extracted from selenized cordyceps militaris link and classified into four groups ( A, B, C and D) by salting-out with (NH4)(2)SO4 of different saturacation ranges: group A(0-30%), group B(30%-50%), group C(50%-75%) and group D(75%-100%). The distribution of protein and selenium in each group was determined by SEC-ICP-MS method. The result shows that the content of soluble selenium in selenized cordyceps militaris link accounts for 69.3% of the total amount and there was selenium in different groups except A. The order of the content in various groups was B > C > D > A. A further study of the selenium bearing protein was made by the analysis with the hyphenation technique of SEC-DAD-ICP-MS. The results obtained demonstrated that their contents were different from each other and their molecular weights were distributed in the range of 114 000 and 1000. It was shown that selenium participated in the synthesis of protein within the Cordycepin body, which played an important role in the transformation of inorganic selenium into organic selenium.