major constituents; the elements Fe, 41, Cu, Si and Br were designated as minor constituents on the basis of analysis of the background com- ponents (coral and lagoon sea water). TABLE 3.13 - Summary of Analytical Methods Element Reagent Cl Na K Mg Ca Sr Mohr Titration Method Beckman Flame Photometer Beckman Flame Photometer Beckman Flame Photometer Beckman Flame Photometer Beckman Flame Photometer Al Cu Si Br Beckman Beckman Beckman Beckman Fe (a) Me thod(@) Beckman Spectrophotometer Spectrophotometer Spectrophotometer Spectrophotometer Spectrophotometer Silver nitrate - Dipyridyl Aluminon Diethyldithiocarbamate Reduced Silicomolybdate Fluorescien-eosin Application of Analytical Methods to the Analysis of Fallout Material, USNRDL Technical Report in preparation TABLE 3.14 - Spectrophotometric Analysis of Minor Constituents Element Solvent rH Medium |Permissible Range Fe Al Cu Si Br H0 H20 CCl, B20 H20 Used 320 - 9.0 4.0 - 7.5 5.7 hed 5.0 - 9.0 (for exe traction) he2 = 6.8 - 5.7 4.54.0] 5.7 Wave Length of |Max. Absorption (mu) 520 535 Optimum Amount of Sample Liquid Solid (m1) > 100 10 435 (in CCl,) |>100 820 (used 700)| 517 10 - 100 <1 (mg) 1M = 50 id = 25 P.O0=500 10 - The elements Fe, Cu, and Si were characterized by very stable , complexes ideally suited for analytical purposes. However, the Si proce~ dure gave soluble Si only. The Al ami Br procedures were sensitive to pl and salt concentration. Solutions of Al and Cu could be concentrated without increasing interferences from other elements to any great extent - the Al being carried on Fe(0H)3 and Cu being extracted into CCl, as the diethyldithiocarbamate complex. 60