QUANTITATIVE DETERMINATION METHOD OF TRACE METALLIC ELEMENT

摘要

PROBLEM TO BE SOLVED: To realize an analyzing method of trace metallic elements in a high purity organic silicone resin by converting and separating a silicone contained in an organic silicon-containing polymer resin into silicon dioxide, and then removing the polymer resin through decomposition, and quantitatively analyzing residual metallic impurities. SOLUTION: During a toluene solvent reflux, a polysilane dissolved in toluene, which is obtained in reaction of sodium and methyl phenyl dichlorosilane. Subsequently, for example, the 1 ml polysilane solution is contained in a Teflon container to be subjected to hydrolysis for 1 hr in a state of 10 ml 5% sulfuric acid added and heated at 100 deg.C, so that silicon dioxide is deposited on its surface. Further, a 5 ml nitric acid and hydrofluoric acid-blended solution is added to the solution to then be decomposed at 230 deg.C for 30 min. Next, a 5 ml mitric acid and perchloric acid blended-solution is added for heat decomposition at 230 deg.C and almost completely evaporation of the solution; resulting in a transparent solution. A specimen solution obtained is put on a Zeema atom absorptive device, and a result of quantification is that Na: 5 ppb, K: 3 ppb, Fe: 8 ppb, Cu: 7, 5 ppb, and Al: 10 ppd.