QUALITY-CONTROL IN ELEMENT ANALYSIS OF PLANT MATERIALS

A worldwide laboratory intercomparison was organized by the Internatio nal Atomic Energy Agency's Analytical Quality Control Services (AQCS) involving the determination of elements in plant materials used for hu man consumption. The main purpose of this work was to evaluate the per formance of our analytical methods including sample preparation and to obtain new reference materials that can be used in our further work. Both materials (spinach and cabbage) were analyzed by inductively coup led plasma atomic emission spectrometry (ICP-AES) and instrumental neu tron activation analysis (INAA). Six subsamples of each material were subjected to our digestion procedure and the solutions were measured b y ICP-AES. The dried samples were analyzed using INAA. Up to 26 elemen ts were determined in plant materials. For easy review of our data a s core has been calculated based on the reference value for each measure d element. According to our results the ICP-AES technique was useful f or determination of the following elements: Ba, Ca, Cr, Fe, K, Mn. Mo, P, S, Sr, Ti. The INAA method was reliable for measurement of Ce, Co, Mn, Na, Rb, Th, and V. (C) 1998 Academic Press.