Dat. num. 9 ref. Sum. (En)

Higher copper contamination on leaf tissue results from copper sulfate sprays. Plant materials so contaminated often require adoption of special analytical procedures. A revision of colorimetric routine techniques for individual determination of micronutrients was found necessary. Manganese and iron were firstly considered. A procedure based on the periodate method proved suitable for manganese and a thiocyanate technique with ethyl acetate as the extractant in the presence of acetone, was introduced for iron determination. From a test sample of ground coffee-tree leaves highly contaminated with copper sulfate, nitro-sulfuric-perchloric acid digests were obtained, on wich repeated measurements for manganese and iron estimation were carried out for reproductibility studies