Separation of Mono- and Dichloroaniline Isomers by Gas Chromatography KARL J. BOMBAUGH' Spencer Chemical Division, Gulf Oil Corp., Merriam, Kan.
b This paper describes the separation of mono- and dichloroaniline isomers by gas chromatography. Using temperature programmed columns containing appropriate amounts of dodecylbenzene sodium sulfonate and silicone oil, complete resolution of all mono- and dichloro isomers (except 2,3 and 2,4) was obtained in 38 minutes. The 2,3 and 2,4 dichloro isomers were separated using either silicone oil or polyethylene glycol 20M. Consideration is given to the para selectivity of the dodecylbenzene sodium sulfonate, and to its utility in preparing columns to meet particular needs.
C
are important intermediates used in the synthesis of a variety of organic chemicals. They are generally prepared by reduction of the appropriate c'IC ratio used most commonly was 60-40; however, it was observed that by increasing or decreasing the 1 I C concentration, the Rj values could be raised or lowvered. Detection sprays used were KMnO,/' H2S04 (500 mg./15 ml. 96% acid) according to the directions of Randerath (6), and 5y0 vanillin in 96y0 HlS04 according to Sigam, Sahasrabudhe, and Levi (5). For quantitative observations of low concentration spots, the photovolt transmission densitometer, Model 501.4, was used. Appropriate filters were selected to give the highest optical density readings for the particular spot color. For higher concentration spots, materials were removed from the plates, dissolved in Skellysolve B, and determined with the Beckman Model DK-2 or Model DU spectrophotometers. RESULTS A N D DISCUSSION
Qualitative Analysis. T L C on silica gel furnishes the analyst with valuable information regarding the identification of compounds suspected
