Trace amounts of transition elements (Co, Cr, Cu, Fe, Mn and V) and other seven elements in optical waveguide samples were
determined by INAA. The contents of impurities in ultra-pure materials are less than those of high-purity materials and of
G.R. grade. The increase of contamination of trace transition elements and iridium from furnace or crucible are observed in
the production of optical glass fibers. Up to seventeen elements were determined in five NBS biological standard reference
materials: Oyster Tissue: SRM-1566, Brewers Yeast: SRM-1569, Spinach: SRM-1570, Orchard Leaves: SRM-1571 and Tuna Fish, and
in four Japanese biological standard reference materials: Tea Leaves B&C, Pepperbush and Shark Meat. The analytical results
in NBS and Japanese standard reference materials are in good agreement with published values and certified values by NBS.