Silver nitrate thin layer plate

Rezanka, T. (1996). Two-dimensional separation of fatty acids by thin-layer chromatography on urea and silver nitrate silica gel plates. J. Chromatogr. A 727(1), 147-152. 

Reagents which selectively retard certain chemical species can be incorporated into a thin-layer plate. Thus, silver nitrate, which forms weak 7t-complexes with unsaturated compounds, aids their separation from saturated compounds. 

Source From Separation of prenylquinones, prenylvitamins and prenols on thin-layer plates impregnated with silver nitrate, in J. Chromatogr. ... 

Pyka, A. Analytical evaluation of visualizing reagents used to detect tocopherol and tocopherol acetate on thin layer. J. Liq. Chromatogr. Relat. Technol. 2009, 32, 312-330. Lichtenthaler, H.K. Bomer, K. LUjenberg, C. Separation of prenylquinones, prenylvitamins and pienols on thin-layer plates impregnated with silver nitrate. J. Chromatogr. 1982, 242, 1%-201. 

A variation of this method is the impregnation of layers with metal ions that act as central atoms. For example, thin-layer plates impregnated with cadmium, zinc, or manganese salts, have been used to separate alkaloids (201,202), amino acids (203), and sulfonamides (204). Impregnation with silver nitrate is especially important in this connection. The Ag ions are able to form complexes with n systems. In this way, selectivity is achieved with respect to the number, position, and geometry of double bonds. This property is used to separate chinones (205), fatty acid derivatives (206,207), lipids (208,210), and sterols (211,212). 

Mono- and diglycerides can be separated from triglycerides by column chromatography on silica gel (Hirsch and Ahrens 1958), florisil (Carroll 1961), and polymerized soy bean oil according to Hirsch (1963). Further resolution of triglycerides is possible on columns of silica gel impregnated with silver nitrate (de Vries 1962) and thin-layer plates prepared in the same way (Barrett et al. 1962, 1963). Silver ions complex with olefinic double bonds with the cis-forms... 

This electrode is perhaps next in importance to the calomel electrode as a reference electrode. It consists of a silver wire or a silver-plated platinum wire, coated electrolytically with a thin layer of silver chloride, dipping into a potassium chloride solution of known concentration which is saturated with silver chloride this is achieved by the addition of two or three drops of 0.1M silver nitrate solution. Saturated potassium chloride solution is most commonly employed in the electrode, but 1M or 0.1 M solutions can equally well be used as explained in Section 15.1, the potential of the electrode is governed by the activity of the chloride ions in the potassium chloride solution. 

Injection volumes of 5pl were used for both sample solutions and comparison standards. Qualitative residue confirmation was accomplished with thin layer chromatography using silica gel. Plates were developed with 1% chloroform in n-heptane, and visualized with alkaline silver nitrate spray as the chromogenic agent. Alternatively, p,p5-DDT and p,p5-TDE were confirmed by treatment with 5% methanoic potassium hydroxide [40]. Partial confirmation of Dieldrin was achieved by fractionating the analysis solution on a Mills column, thus isolating Dieldrin in the second fraction [35],... 

Production of the film or plate. A thin layer of gelatin containing a colloidal dispersion of silver bromide is placed on a film (made of cellulose nitrate or cellulose acetate) or a glass plate. After drying, the film (or plate) is ready for use. 

Mosinska [106] has described a semi-quantitative thin layer chromatographic method for the determination of trichlorphon in potable water. The sample is extracted with redistilled chloroform. The extract is dried with sodium sulphate, reduced in volume to 5mL in vacuo and then evaporated to dryness in a stream of air. The residue is dissolved in acetone and chromatographed on chloride-free silica gel G plates (activated at 100°C for lh) with benzene-methanol (17 3) as solvent. The spots, revealed with ammoniacal silver nitrate in acetone, are compared with those of standards for semi-quantitative determination. The detection limit is 0.02mg L 1 and the efficiency of extraction is 70%. 

Analysis by TLC. Confirmation of the identity of the halogenated compounds in the soil samples was achieved by resolution of selected extracts on TLC plates, followed by gas chromatography of the separate compounds eluted from the plates. The thin layer chromatography system of Kovacs (6) was used, and the halogenated compounds were detected with the silver nitrate-2-phenoxyethanol reagent. Comparison with standards chromatographed on the same plates permitted an estimate of the pesticide concentrations. 

The silver-silver chloride electrode consists of a mounted platinum screen that has been heavily plated with silver from a cyanide bath, rinsed, aged in an acidified silver nitrate solution, rinsed, coated with a thin layer of silver chloride by anodizing in a dilute HCl solution (preferably no more than a few days before use), and kept in dilute HCl pending use. This is mounted in a glass sleeve with a small hole in the bottom to admit the cell... 

Thin-layer chromatography on silver nitrate impregnated silicic acid plates is... 

TLC offers a number of advantages over column chromatography. It is more rapid and sensitive, gives better resolution and is usually much quicker. Moreover, the apparatus required is minimal and, especially if plates are made in the laboratory, the technique is inexpensive. By incorporating various chemicals into the thin layer, special lipid separations can be made. For example, silver nitrate allows fatty acids (or more complex lipids) to be separated on the basis of their unsaturation. Silicone oil-silica gel TLC works on the basis of reverse-phase separation and can be used to fractionate fatty acid mixtures based on their hydrophobicity, with shorter chain or unsaturated components migrating faster. Boric acid impregnation allows separation of threo- or erythro- isomers of vicinal diols or fractionation of molecular species of ceramides. 

Figure 3.4 Thin layer chronnatography of isomeric octadecenoates on silver nitrate-silica gel G (30 70). The position of the double bonds is indicated by the sample number, samples being 2. 3, 6. 9. 11 and 12 frans-octadecenoates, 3, 6. 8. 9.10,11,12 and 15 c/s-octadecenoates and the vinyl compound 17-octadecenoate (in mixtures, trans runs ahead of cis). The plate was developed at -25°C. three times with toluene. The spots were located with chlorosulphonic acid-acetic acid (1 2) and charring. Reproduced with kind permission of Dr L.J. Morris (1987) and the Elsevier Science Publishers. BV. from Journal of Chromatography, 31. p. 74, Figure 2(a).

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