Determination of Trace Elements in Alfalfa by Flame Atomic Absorption Spectrophotometry

Ten kinds of trace elements(Na,K,Ca,Mg,Fe,Zn,Cu,Mn,Cr and Co) in the neck,leaf,flower and seed of alfalfa are detected and analyzed by flame atomic absorption spectrophotometry(FAAS).The samples were dissolved with HNO3+HClO4.The precision and recovery rate for different elements within the limits of working curves were good,the range of recoveries(n=5) was 95%～105% and the RSD was lower than 5%.The results indicated that the content of trace elements was different in neck,leaf,flower and seed of alfalfa.In the neck,the content of different trace elements was found to be CaKZnNaFeMgMnCrCuCo.In the leaf,the content was found to be CaKZnMgNaFeMnCoCuCr;In the flower,the content was found to be MgKZnNaMnFeCaCuCrCo;In the seed,the content was found to be KMgFeMnZnNaCaCuCoCr.The content of K,Mg,Zn,Na and Ca was in the order of leafneckflowerseed;the content of Fe and Cr was in the order of neckleafseedflower;The content of Mn,Co and Cu was in the order of leafseedneckflower.The results showed that some elements essential to human body such as Ca,K,Zn,Mg and Cr of alfalfa are abundant in alfalfa,which is beneficial to the development of alfalfa.