ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Estimation of aromatic compounds separated by paper or thin-layer chromatography

J. Franc, M. Hájková, and V. Jehlička

Forschungsinstitut für organische Synthesen, Pardubice-Rybitvi

Abstract: The relative standard deviations (v) of various methods for evaluating chromatograms were compared. For estn. of aromatic acids (I), the following procedure (v = 2.8) is recommended: Exactly 3-10 λ of 2.5% I in C5H5N is applied to Schleicher & Schuell paper 2045BG, and developed with BuOH-EtOH-C₅H₅N-H₂O (3:1 :1:1) for 16 hrs. at 20°. The corresponding Rf values are: BzOH (0.58), p-MeC₆H₄CO₂H (0.61), p-MeO₂CC₆H₄CO₂H (0.45), o-C₆H₄(CO₂H)₂ (0.30), p-C₆H₄(CO₂H)2 (0.15), and 1,3,5-C₆H₃(CO₂H)₃ (0.06). The chromatogram is dried for 3 hrs. in air, and developed with a cold-satd. aq. soln. of 2,6-dichlorophenolindophenol. The spots are cut out, cut into small strips, transferred into 10 ml.-flasks, and extd. with 200 μl. of 0.05N NaOH and 2 ml. of water for 10 min. at 60°. The soln. is back-titrated with 0.05N HCl; a blank is run with a paper of the same area. For estn. of dinitroanthraquinones (II), a sample of II in HCONMe₂ (III) is applied on Schleicher & Schuell paper 2045 A, impregnated with 30% aq. III. After development with cyclohexane-C₆H₆ by the over-run technique, spots of the sepd. 1,5-and 1,8-isomers of II are cut out from the dried paper and eluted with 2.5 ml. of III overnight. A buffer (2.5 ml.), prepd. from 3 ml. of AcOH and 6.8 g. of AcONa in 250 ml. of III, is added to the eluate, and the mixt. is polarographed in the absence of the chromatographic paper. If analogous thin-layer chromatography on Al₂O₃ is used, the adsorbent does not interfere with the polarographic estn., v being 4.8 in this case. For estn. of 1-aminoanthraquinone, 1,5-diaminoanthraquinone, and 1,8-diaminoanthraquinone, 0.02-ml. samples of a 0.04% soln. of sample in III were chromatographed on a thin layer of Al₂O₃, and after drying evaluated directly on a densitometer, model ERI-10 (Zeiss, Jena); v = 6%.

Full paper in Portable Document Format: 178a542.pdf (in Czech)

Chemical Papers 17 (8) 542–549 (1963)