A densitometric study of co-elution in thin-layer chromatography, and its physicochemical modeling

• Autorzy: Pieniak A. , Kaczmarski K. , Sajewicz M. , Zapała W. , Gołębiowska A. , Tomala R. , Kowalska T.
• Języki publikacji: EN

Abstrakty

EN

In our earlier efforts to scrutinize lateral interactions among test analyte molecules, and their impact on the shape of the respective concen-tration profiles of thin-layer chromatographic bands, we focused our atten-tion on single analytes able to self-associate by hydrogen bonding of their functional groups (and primarily on alcohols and carboxylic acids). Distinct demonstration of lateral interactions is possible only when the analyte is applied to a stationary phase in an amount within the non-linear region of its adsorption isotherm. One must, moreover, ensure the chromatographic conditions are relatively mild, i.e. a low-activity adsorbent used as statio-nary phase and a low-polarity mobile phase. Such conditions guarantee that lateral interactions among the analyte molecules are to a large extent unaffected and therefore observable by densitometry. In the TLC study reported in this paper we focused on co-elution of a binary mixture of test analytes. For the purpose of our experiment we chose two such mixtures: (i) a carboxylic acid (2-phenylbutyric acid, which is, simultaneously, a Lewis acid and a Lewis base (AB)) and a ketone (benzophenone, which is a Lewis base (B) only); and (ii) an aliphatic alco-hol (5-phenylpentanol, which is, simultaneously, a Lewis acid and Lewis base (AB)) and the same ketone (i.e. benzophenone). Because of their fun-ctionality, these two pairs of compounds can form mixed associative struc-tures by hydrogen bonding. It is worthy of note that the retention (i.e. RF values) of each of the two analytes from a given pair is perceptibly different if each is chromatographed as a single species. Using mild chromatographic conditions and working in the non-linear region of the adsorption isotherm we managed to (i) demonstrate co-elution of the two analytes from each pair in the form of a single chromatographic band; (ii) suggest (optional or complementary) three different physicochemical explanations of their den-sitometrically measured concentration profiles; and (iii) perform semi-quantitative simulations of these profiles. Most of the results discussed were obtained by planar chromato-graphy (TLC) but some experiments were repeated with a column-chro-matographic technique, HPLC, using fully analogous working conditions (i.e. low-activity carbohydrate stationary phase and low-polarity hydrocar-bon mobile phase). Some of the results obtained by HPLC were similar to those from planar chromatography whereas others were dissimilar.

• Wydawca: University of Silesia in Katowice ; Akademiai Kiado
• Czasopismo: Acta Chromatographica
• Rocznik: 2004
• Tom: No. 14
• Strony: 16--36
• Opis fizyczny: Bibliogr. 13 poz., rys., tab.

Twórcy

autor

Pieniak A.

• Institute of Chemistry, Silesian University, 9 Szkolna Street, 40-006 Katowice, Poland

autor

Kaczmarski K.

• Faculty of Chemistry, Technical University of Rzeszów, Rzeszów, Poland

autor

Sajewicz M.

• Institute of Chemistry, Silesian University, 9 Szkolna Street, 40-006 Katowice, Poland

autor

Zapała W.

• Faculty of Chemistry, Technical University of Rzeszów, Rzeszów, Poland

autor

Gołębiowska A.

• Institute of Chemistry, Silesian University, 9 Szkolna Street, 40-006 Katowice, Poland

autor

Tomala R.

• Institute of Chemistry, Silesian University, 9 Szkolna Street, 40-006 Katowice, Poland

autor

Kowalska T.

• Institute of Chemistry, Silesian University, 9 Szkolna Street, 40-006 Katowice, Poland

Bibliografia

• [1] R. Smits, C. Vanroelen, D.L. Massart, Fresenius Z. Anal. Chem., 273, 1 (1975)
• [2] M.W. Watson, P.W. Carr, Anal. Chem., 51, 1835 (1979)
• [3] L.R. Snyder, J. Chromatogr. Sci., 16, 223 (1978)
• [4] Sz. Nyiredy, B. Meier, C.A.J. Erdelmeier, O. Sticher, J. High Res. Chromatogr. Chromatogr. Commun., 8, 186 (1985)
• [5] W. Prus, K. Kaczmarski, K. Tyrpień, M. Borys, T. Kowalska, J. Liq. Chromatogr. Related Technol., 24, 1381 (2001)
• [6] K. Kaczmarski, W. Prus, C. Dobosz, P. Bojda, T. Kowalska, J. Liq. Chromatogr. Related Technol., 25, 1469 (2002)
• [7] M. Sajewicz, A. Pieniak, R. Piętka, K. Kaczmarski, T. Kowalska, Proc. Int. Symp. Planar Separations “Planar Chromatography 2003”, Budapest, Hungary, 21–23 June 2003, pp. 407–414
• [8] M. Sajewicz, A. Pieniak, R. Piętka, K. Kaczmarski, T. Kowalska, Acta Chromatogr., 14, 5 (2004)
• [9] K. Kaczmarski, M. Sajewicz, A. Pieniak, R. Piętka, T. Kowalska, J. Liq. Chromatogr. Related Technol., 2004, in press
• [10] M. Sajewicz, A. Pieniak, R. Piętka, K. Kaczmarski, T. Kowalska, J. Liq. Chromatogr. Related Technol., 2004, in press
• [11] C.-H. Wang, B.J. Hwang, Chem. Eng. Sci., 55, 4311 (2000)
• [12] I. Quinones, G. Guiochon, J. Chromatogr. A, 796, 15 (1998)
• [13] K. Kaczmarski, D. Antos, J. Chromatogr. A, 862, 15 (1999)