Silver nitrate layers

Separation on silver nitrate layers is based on complex formation by the Ag" ions with the Jt-electrons of one or more double or triple bonds of the substances being separated and depends on the strength of the bond [22]. As an example, Kraus describes the separation of some CIO alcohols which cannot be separated by either partition or adsorption chromatography without impregnation [21, experiment 13.9.9]. 

The D-group can be separated on silica gel-silver nitrate layers [7, 19, 101]. In particular the socalled critical pairs of vitamin D-esters, palmitate-oleate, myristate-linoleate and laurate-linolenate can... 

Table 61. Separation of sterols and their acetates on silica gel O-silver nitrate layers [43] Solvents A and B, see text detection with 0.2% dibromofluoresoein...

The dipping unit can also be employed to impregnate adsorbent layers. It is easy in this way to produce tungstate- [127] or silver nitrate-impregnated layers for separating oligosaccharides or unsaturated compounds. 

Phosphomolybdic acid essential oil components stabilization of the silver nitrate-impregnated adsorbent layer [207]... 

The reagent can be employed on silica gel, silver nitrate-impregnated silica gel, carboxymethylcellulose-containing silica gel, kieselguhr and Si 50000 layers RP phases are not suitable. 

Note Rhodamine B is a universal reagent that can be used on silica gel, talc, starch [5] and cellulose layers, just as on urea [1] or silver nitrate-impregnated [7] phases. Liquid paraffin-impregnated silica gel and RP layers are less suitable, since the background to the chromatographic zones is also intensely colored. It is often possible to increase the detection sensitivity by placing the plate in an atmosphere of ammonia after it has been sprayed or dipped, alternatively it can be oversprayed with sodium or potassium hydroxide solution. 

Fig. 5. HREM of enclosed silver particles in CNTs. The metallic particles were obtained by electron irradiation-induced decomposition of introduced silver nitrate. Note that the gases produced by the nitrate decomposition have eroded the innermost layer of the tube.

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. 

The reagent can be used, for example, on silica gel, kieselguhr and Si 50000 layers as well as on aluminium oxide, cellulose or chiral layers. Neither do difficulties occur on RP 18, Diol, NHj and CN phases. Silver nitrate- [4] and calcium oxalate-impregnated layers [9] are also suitable. However, polyamide phases are colored yellow. 

Imidazole derivatives 380 Imperatorin 65 Impregnation of TLC layers 86 -with caffeine 86 -with silver nitrate 86 -with tungstate 86 Indeno(l,2,3-cd)pyrene 39,85 Indicators, pH- 303 -, reagents 45 Indium cations 144 Indoleacetic acid 45... 

Acrylonitrile came into contact with silver nitrate and was kept in this way for a long time. It gave rise to a violent detonation thert was put down to nitrile polymerisation, which formed successive layers of pilymer at the surface of the salt particles the temperature rise that was caused accelerated the polymerisation gradually. 

These aspects of solvent property similarly apply to precoated impregnated silica gel plates, e.g., by ammonium sulfate, silver nitrate, or magnesium acetate, as well as to microcrystalline cellulose precoated plates. On preparative RP phases, water has the lowest elution power. Therefore, more polar or aqueous solvents should be preferred. In contrast to HPTLC RP-18 layers, on which such aqueous solutions remain as a drop on the surface and are not able to penetrate through the lipophilic layer, on preparative RP phases, pnre aqneons application solutions can be apphed owing to the minor degree of C18 modification. 

The silver(I) complexes with the tetrakis(methylthio)tetrathiafulvalene ligand have been reported, the nitrate salt presents a 3D structure with an unprecedented 4.16-net porous inorganic layer of silver nitrate,1160 the triflate salt presents a two interwoven polymeric chain structure.1161 The latter behaves as a semiconductor when doped with iodine. With a similar ligand, 2,5-bis-(5,5,-bis(methylthio)-l,3,-dithiol-2 -ylidene)-l,3,4,6-tetrathiapentalene, a 3D supramolecular network is constructed via coordination bonds and S"-S contacts. The iodine-doped compound is highly conductive.1162 (Methylthio)methyl-substituted calix[4]arenes have been used as silver-selective chemically modified field effect transistors and as potential extractants for Ag1.1163,1164... 

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. 

Lead tetraacetate is added in small quantities, with stirring, to an ice-cold suspension of 11 g. of ethyl 3-(D-arabino-tetrahydroxybutyl)-5-methyl 4-furoate in 100 ml. of benzene plus 40 ml. of glacial acetic acid. Addition is stopped when there is a positive reaction with potassium iodide-starch paper. The mixture is stirred for a further ten minutes, filtered, and the benzene solution washed twice with water. The benzene layer is then dried with anhydrous sodium sulfate, filtered, and the filtrate evaporated to dryness. The residue (6 g.) is mixed with a solution of 7.5 g. of sodium hydroxide plus 20 g. of silver nitrate in 40 ml. of water, and heated for 40 minutes on a steam bath. The aqueous solution is filtered, acidified to Congo Red while being cooled with ice, and the crystals formed are removed by filtration, washed with ice-cold water, and dried over phosphorus pentoxide in the vacuum desiccator yield, 2.2 g. After recrystallization from water, the product has m. p. 234r-235°. 

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. 

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