Retinol chromatography

Retinyl acetate [127-47-9] M 328.5, m 57". Separated from retinol by column chromatography, then crystd from MeOH. See Kofler and Rubin [Vitamins and Hormones (NY) 18 315 1960] for review of purification methods. Stored in the dark, under N2 or Ar, at 0°. See Vitamin A acetate p. 574 in Chapter 6. 

Separated from retinol by column chromatography on water-deactivated alumina with hexane containing a very small percentage of acetone. Also chromatographed on TLC silica gel G, using pet ether/isopropyl ether/acetic acid/water (180 20 2 5) or pet ether/acetonitrile/acetic acid/water (190 10 1 15) to develop the chromatogram. Then recrystd from propylene at low temperature. 

Li, H. et ah. Determination of carotenoids and all-fra 5-retinol in fish eggs by liquid chromatography-electrospray ionization-tandem mass spectrometry, J. Chromatogr. B, 816, 49, 2005. 

Retinyl acetate [127-49-9] M 328.5, m 57 . Separated from retinol by column chromatography, then... 

MacCrehan, W.A. and Schonberger, E. 1987. Determination of retinol, a-tocopherol, and a-caro-tene in serum by liquid chromatography with absorbance and electrochemical detection. Clin. Chem. 33 1585-1592. 

Adsorption chromatography is a powerful means of separating cis and trans isomers of unsaturated compounds, the separation mechanism being attributed to a steric fitting of solute molecules with the discrete adsorption sites. This is illustrated in the isocratic separation of six geometric isomers of vitamin A obtained by photolysis of all-fran.v-retinol (109). 

Reversed-phase chromatography using semiaqueous mobile phases can separate all-trans-retinol from 13-cis-retinol, albeit rather poorly. Further separation of the minor cis isomers is not... 

B Stancher, F Zonta. High-performance liquid chromatography of the unsaponifiable from samples of marine and freshwater fish fractionation and identification of retinol (vitamin A)) and dehydroretinol (vitamin A2) isomers. J Chromat 287 353-364, 1984. 

E Brinkmann, L Dehne, HB Oei, R Tiebach, W Baltes. Separation of geometrical retinol isomers in food samples by using narrow-bore high-performance liquid chromatography. J Chromat A 693 271-279, 1995. 

Masuda et al. have reported the supercritical fluid chromatography of retinol palmitate and tocopherol acetate using an octadecylsilyl silica gel column with ethanol-modified carbon dioide as the mobile phase [43]. Both retinol and tocophenol eluted within 5 min. The method was applied to the determination of these compounds in an ointment formulation. The method was found to be linear for both retinol and tocophenol from 0.5 to... 

Y. Satomura, M. Kimura, and Y. Itokawa, Simultaneous determination of retinol and tocopherols by high-performance liquid chromatography, J. Chromatogr., 625 67 (1993). 

A. BenAmotz, Simultaneous profiling and identification of carotenoids, retinols, and tocopherols by high performance liquid chromatography equipped with three-dimensional photodiode array detection, J. Liquid Chromatogr., 18 122 (1995). 

Wang, Y. Xu, X. van Lieshout, M. West, C.E. Lugtenburg, J. Verhoeven, M.A. Creemers, A.F.L. Muhilal and van Breemen, R.B. 2000. A liquid chromatography-mass spectrometry method for the quantification of bioavailability and bioconversion of P-carotene to retinol in humans. Anal. Chem. 72 4999-5003. 

On silica gel thin-layer chromatography (TLC) plates eluted with a mixture of cyclohexane-ethanol (97 3, by volume), vitamin Aj alcohol and re/ro-vita-min Ai alcohol (Rp values 0.10 and 0.09, respectively) are separated from the pair vitamin Aj acetate/re/ro-vi-tamin Aj acetate (Rp values 0.48 and 0.45, respectively) and vitamin Aj palmitate (Rp value 0.78) and anhy-drovitamin Aj (Rp value 0.87) [5]. Geometric isomers of retinol are separated on silica gel plates using... 

Barua, A.B. Kostic, D. Barua, M. Olson, J.A. Determination of retinol and retinoic acid in capillary blood by high-performance liquid chromatography. J.Liq.Chromatogr., 1995, 18, 1459-1471... 

Takeda, N. Yamamoto, A, Simultaneous determination of 13-cis- and all-trans-retinoic acids and retinol in human serum by high-performance liquid chromatography. J.Chromatogr.B, 1994, 667, 53—59... 

Gel chromatography on Sephadex LH-20 offers good separation of biologically active forms of vitamin A both in standard solutions and in biological materials [153]. Holasova and Blattn [154] studied specific binding of an active form of vitamin A, retinol, to retinol receptors. 

Alternatively, where samples are extracted into organic solvents, normal phase HPLC can also be used. This option is particularly valuable for the resolution of optical isomers of the A vitamins and, for example, 13-cw-retinol can be resolved using this system (Egberg et al., 1977). Retinoyl species may be converted to retinol prior to chromatography but the subsequent profile is difficult to interpret because of the number of possible intermediates that may also be generated. A computer-assisted analysis of vitamin A extracts from two species of tobacco leaf using non-aqueous reversed phase is shown in Fig. 11.8.2. 

Plasma was separated by centrifugation and the concentrations of total (deuterated and protonated) /3-carotene and total retinol in all plasma specimens (after saponification) were measured by high-performance liquid chromatography (HPLC) the fractional standard deviation (FSD) of the analytical method was <0.04. Ratios of /3-carotene-dg//3-carotene in all plasma specimens were determined by HPLC the FSD of this analytical method was 0.0325. Ratios of retinol-dVretinol in all plasma specimens were determined by gas chromatography mass spectrometry the FSD of this method was 0.045. Details of these laboratory analytical procedures are previously described (Handelman etal., 1993 Dueker etaL, 1993,1994). The physiologic compartmental model of the dynamics of /3-carotene metabolism based on these data is also previously described (Novotny et al.,... 

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