原子吸光分析法による有機化合物中のハロゲン元素の定量分析

抄録

In the previous paper, authors reported on the quantitative determination of halogen-containing drugs by atomic absorption spectrophotometry using air acetylene flame with good accuracy. In this study, it has been found that determination of sublimable halogen containing compounds such as 1-chlorophenazine, hexachlorobenzene and ο-bromobenzoic acid may be carried out successfully by employing a more proper reductive decomposition method.
The recommended procedures are as follows: Nonsublimable compounds, such as, p-chloroaniline and p-bromoacetanilide, were fused with metallic sodium of 1020 times as much as the weight, and after an excess metallic sodium being decomposed with water, the residues were filtered off and the filtrate was used for the measurement. Then, a proper amount of the sample solution (14 ml) was made acidic with nitric acid, followed by the addition of 5ml of 100μg/ml silver nitrate solution, and the resultant solution was warmed on a water-bath for 1 min. It was kept standing for 30min at a roomtemperature, the precipitates were filtered off and the filtrate was diluted to 100ml with water, then an excess amounts of silver were determined by atomic absorption spectrophotometer. However, this procedure is not applicable to the sublimable compounds such as 1-chlorophenazine, and the following manipulation was performed according to the method of Yano, et al. That is, in a 50ml capacity of flask, a compound was dissolved in 2 ml of alcohol (n-butanol, iso-amyl alcohol, etc.) with a reflux condenser and warmed. After an addition of metallic sodium, the resultant solution was boiled for 30 min and then it was kept standing for 10 min at a room-temperature. After an addition of water, insoluble materials were filtered off and the filtrate was used for the measurement. Standard solutions of Cl, Br, and I for working curves were prepared according to the similar procedures. In order to ascertain the repeatability, the compounds of various halogen contents were analyzed and the standard deviation was calculated to be 0.210.53.In conclusion, this method has been found to be applicable to the quantitative determination of halogen elements in organic compounds.