Pigment separation

In a recently pnblished example of betaxanthin analyses in a complex food matrix, 19 betaxanthins were assigned in yellow Swiss chard petioles. Mass spectrometric measnrements are even more helpfnl if nnknown betacyanin structures are to be elucidated. While betacyanic plant materials such as red beet and amaranth may still be commercially available for coinjection experiments and comparison with samples under investigation, it may be an easier task to first optimize pigment separation followed by mass spectrometric measurements. 

The chromatographic profiles of pigments separated on normal and microbore columns are displayed in Fig. 2.4. 

B) Synthetic BC and excess B are coupled with [ S]sulfanilic acid diazo reagent in presence of ethanol azo derivatives are extracted in presence of cold carrier pigments, separated chro-matographically and counted by radio scanning... 

Currently, only a few plants still produce rather coarse blacks (mean particle diameter 100 nm) with special properties. They are used as nonreinforcing or semireinforcing blacks in rubber goods and as tinting black with a low pigment separation tendency. 

Normal-phase sorbents such as silica and Florisil are used to isolate low to moderate polarity species from nonaqueous solutions. Examples of applications include lipid classification, plant pigment separations, and separations of fat-soluble vitamins from lipid extracts, as well as the clean-up of organic solvent concentrates obtained from a previous SPE method or liquid-liquid extraction. Alumina is used to remove polar species from nonaqueous solutions. Examples include vitamins in feeds and food and antibiotics and other additives from feed. Normal-phase chromatography has been used for a number of years, and most applications for normal-phase column chromatography may be easily transferred over to normal-phase SPE. 

Bile Pigments, Separation and Determination "(Brodersen and Jacobsen). 17 31... 

Standard Test Method for Quahtative Determination of Nature of Solvent Composition in Solvent-Reducible Paints Standard Test Method for Antimony Oxide in White Pigment Separated from Solvent-Reducible Paints Standard Test Method for Sulfide in White Pigment Separated from Solvent-Reducible Paints... 

Chem. Descrip. Methyl trimethoxy silane CAS 1185-55-3 EINECS/ELINCS 214-685-0 Uses Pigment and filler treatment in solv. and water-based systems primer reduces pigment separation and floating improves disp. adhesion promoter... 

Uses Surf, control additive, flow additive for solv.-based paint systems Features Prevents vertical pigment separation antisilicone additive Properties Clear liq. sp.gr. 0.93 dens. 7.8 Ib/gal vise. 30-36 mPas flash pt. 19 C ref. index 1.398-1.402 100% act. 

Sample Applied pigment Esterified pigment Separation by TLC of labeled esterified pigment ... 

A review on HPLC methods for pigment separations has been given by Roy (1987). 

Table 27-2. Examples of gradient programmes for HPLC pigment separation. Percentages are v v.

Figure 18.1 Chloroplast pigments separated from 3-5 pi of leaf extract by thin-layer chromatography on silica gel sheets. N = Neoxanthin V = viola-xanthin L = lutein b = chlorophyll b a = chlorophyll a C = carotene F = solvent front X = origin Y = yellow 0 = orange G = green III = blue-green over HCI vapors, = blue over HCI vapors Ac = acetone 10 = isooctane DE = diethyl ether. [Reprinted with permission of the Journal of Chemical Education, Washington, DC, from Strain and Sherma (1969).]...

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