ICP-AES Determination of Trace Elements in Peel of Carya Cathayensis with Microwave Assisted Sample Digestion

ICP-AES was applied to the determination of 11 trace elements,i.e.,Na,K,Zn,Fe,Mn,Cu,Mg,Ca,Ni,Cr and As,in peel of carya cathayensis.The peel sample was air-dried,baked at 45 ℃ for 24 h in a drying oven,and pulverized to powder.It was divided into 3 portions,and treated by different ways of extraction.The effect of different ways of extraction on the contents of the trace elements was studied.The dried powder samples after the extraction treatments were digested with HNO3-HCl mixture in the MARS microwave digestor under prescribed programs.Values of recovery of the method for the 11 elements were in the range from 86% to 107%.Lowering of contents of the elements (besides Ni) to different extent was observed after extraction either with C2H5OH+H2O (1+1) mixture or with water only as the extractant,the content of arsenic,which is a poisonous element,was lowered to the extent of 40.0% and 62.5% by extraction with alcoholic solution or with water respectively.