芳香烴之紫外光譜分析　第三報　二甲苯及乙苯之定量

Determination of Aromatics by Ultraviolet Sepctrophotometry III. Determination of Xylene lsomers and Ethyl Benzene

林文喜(Wen-Shi Lin)

《化學》 56年2期 (1967/06) Pp. 51-54

https://doi.org/10.6623/chem.1967011

摘要

採用95％乙醇爲溶劑，測定隔位二甲苯，隣位二甲苯，對位二甲苯及乙苯的紫外光吸收光譜。其中隔位二甲苯及隣位二甲苯的吸收光譜與用異辛烷爲溶劑的吸收光譜完全一致。對二甲苯及乙苯的吸收光譜與用異辛烷爲溶劑的吸收光譜大致相同，惟後者可測得之一些小尖峰却消失。除乙苯-95％乙醇溶液外各二甲苯異構體-95％乙醇溶液的濃度吸光度的關係，均與Beer法則稍有偏差。其偏差大小順序是對位二甲苯＞隔位二甲苯＞隣位二甲苯。由所測得光係數、導出了各C_8芳香烴之計算式。校驗結果隔位二甲苯，隣位二甲苯，對位二甲苯及乙苯的平均誤差、分別爲1.4，1.7，1.0、及0.6％。此報告是乙苯及三種二甲苯異構體的紫外光譜分析結果。所用裝置、溶劑及符號與第一報相同。乙苯及各二甲苯異構體標準物，均採用美國Eastman Organic Chemical公司出品。

並列摘要

The ultraviolet absorption spectra of m-, 0-, p-xylene and ethyl benzene in 9596 ethanol were determined, and the results were compared with those reported by other workers in case of Cs aromatics in iso-octane. The absorption spectra of 111- and a-xylene were the same as those in iso-octane. The other absorption spectra of p-xylene and ethyl benzene were almost the same as those in iso-octane, but some small peaks were disappeared. The relations between concentration and absorbance of xylene isomers were deviated from Beer's law, but that of ethyl benzene were not. From the absorp tion coefficent determined, four formulas relating the absorbances and each concentrations of C, aromatics in mixture were derived. The mean errors of m-, 0-, p-xylene and ethyl benzene concentration calculated from these formulas were 1.4, 1.7, 1.0 and 0.6,'16 respectively, when checked with synthetic samples.