Silanization silica gel

Analysis of neutral product for active species. The di- and poly sulfonates present in AOS have been isolated from monosulfonates by column chromatography using silanized silica gel by Puschmann [109]. The content of mono-and disulfonates in the fractions obtained were determined gravimetrically. 

Octyl silane and butyl silane silica gels... 

Silica gel 60 F2S4, alumina 60 F2S4 E silanized silica gel GF254 Cyclohexane-boizene-diethylamine. Cydohexane cetone-diethylainine. methanol-aqueous 2S% ammonia for silica gel. Benzene-acetone for alumina Acetone-water-aq. 25% NH3 for silanized silica gel. 51... 

The chromatographic behavior of 4//-pyrido[ 1,2-a]pyrimidin-4-ones and their 6,7,8,9-tetrahydro derivatives was studied on silanized silica gel layers using a aqueous mobile phases by TLC in normal chambers, and by OPTLC in a pressurized ultramicrochamber (88MI1-88MI3 89MI10 90MI1). 

TLC was carried out on various types of plates silica gel, silanized silica gel, cellulose and alumina, as well as in several different solvent systems benzene, chloroform, cyclohexane, benzene/acetone (90 10), cyclohexane/ethyl acetate (95 5), cyclo-hexane/acetone/triethylamine (70 25 5), hexane/benzene (60 40) and hexane/ether (80 20). Spots were either visualized by ultraviolet or developed by pulverization of a 1% blue B salt aqueous solution. 

Tests using unlabeled DANS-A9-THC showed that the main difficulty encountered was hydrolysis of the ester-phenol bond on the chromatographic plate. The most satisfactory separations were obtained in the dark on silanized silica gel plates. Under these conditions, DANS A9-THC remained stable throughout chromatography. 

Nucleosides (4) silanized silica gel-60 Reversed micelles of sodium dioctylsulfo-succinate in cyclohexane TLC 87... 

Amino add and symbol SiUca gel G (A) Micro- crystalline cellulose (B) Fixion 50-X8 (NaA (C) Silanized silica gel +4% HDBS (D) pi... 

The data of Table 1 show that complete resolution of basic amino acids (Arg, His, Lys) and of neutral amino acids which differ in their side-chain carbon atom number (e.g., Gly, Ala, Met, Val, Leu, or He) are possible on home-made plates of silanized silica gel (C2) impregnated with a 4% solution of dodecyl-benzensulfonic acid in 95% ethanol. More compact spots can be obtained on RP-18 ready-to-use plates dipped in the same solution of the surfactant agent. 

Peptide antibiotics are composed of the peptide chain of amino acids, d and l, covalently linked to other moieties. Most peptides are toxic and are poorly absorbed from the alimentary tract. Peptide antibiotics are difficult to analyze in biological and food samples, as they are similar to matrix components. They can be separated on silica gel, amino silica gel, and silanized silica gel plates. A variety of mobile phases are applied, from a simple one like chloroform-methanol to a multicomponent one like n-butanol-butyl acetate-... 

Substituted monocyclic phenols have been widely studied on several stationary phases (alumina, silica gel, cellulose, polyamide, silanized silica gel) and also on chemically modified adsorbents (cyano- and amino-silica plates), ion-exchange layers, and impregnated plates. 

Alkylphenols, nitrophenols, halogenophenols and polyhydroxybenzenes have been extensively studied on a thin layer of anion and cation exchangers with cellulose, paraffin, and polystyrene matrices and on silanized silica gel impregnated with anionic and cationic surfactants. The best results have been obtained by using cation exchangers and anionic surfactants as impregnating agents [4,5]. 

The parameters that determine the retention of phenols on layers of silanized silica gel, untreated and impregnated with anionic surfactants, are the same that affect retention on cation exchangers (i.e., the organic modifier percentage, the ionic strength, and, particularly, the pH of the eluent). 

In general, silica gel has been more widely used than cellulose, polyamide, and silanized silica gel for the separation of phenolic acids and their derivatives. 

Sfiica impregnated with saturated and unsaturated hydrocarbons (squalene, paraffin oil), silicone and plant oils, complexing agents (silver ions, boric add and borates, unsaturated and aromatic compounds), tigands (EDTA, digitonin), and transition metal salts silanized silica gel impregnated with anionic and cationic surfactants Cross-linked, polymeric dextran gels (Sephadex)... 

Cellulose, cellulose triacetate, silanized silica gel impregnated with the copper(II) complex of (2S, 4R, 2 iJ5)-A-(2 -hydroxydodecyl)-4-hydroxyproline (CHIRALPLATE, HPTLC CHIR)... 

Diol-modified sfiica gel Cellulose-based ion exchangers Polystyrene-based ion exchangers Ammonium tungstophosphate Sfiica gel impregnated with paraffin, silicon, and plant oils Silanized silica gel impregnated with anionic and cationic surfactants... 

Forni and Massarani1 described the analysis of colchicine and col chi coside in plant material. They used a silanized silica gel as stationary phase and a gradient of acetonitrile... 

Sterol intermediates in cholesterol biosynthesis have been resolved by a three-step chromatographic procedure.128 A detailed study of reversed-phase thin-layer chromatography of a wide variety of steroids (on silanized silica gel) includes a correlation of AJ M values of substituents with hydrophobicity parameters.129... 

Liquid chromatography can be recommended as analytical method to determine the equilibrium concentration on study the adsorption of non-volatile and unstable substances from solutions under static condition [10]. Cymarin (one of cardiac glycosides) adsorption on silanized silica gel from water - ethanol solvent was investigated as the example. 

Fig. 5b shows the initial linear part of the isotherm of cymarin adsorption on silanized silica gel obtained from the chromatographic peaks. In this region of the isotherm the concentrations are 100 times lower than in the region of the isotherm measured under static conditions (Fig. 5a). The slope of the isotherm in Fig. 5b gives a Henry constant equal to 5.05 0.02 cm /g what coincides (within the limit of possible errors) with the extrapolated slope of the adsorption isotherm obtained under static conditions (Fig. 5a, Kns,c,i = 5.00 cm /g). For the given system (cymarin, water-ethanol eluent, LiChrosorb RP-2), the values of the Henry constants determined when studying the adsorption under both static and chromatographic (dynamic) conditions were almost equal, although the adsorbent particles were rather large (about 30 fim) and the pores were not very wide (about 6 nm). This proves that under the chromatographic conditions used all the surface...

Methylaluminium bis(2,6-di-t-butyl-4-methylphenoxide) complexes with methyl ethyl ether in preference to diethyl ether and adsorbed on silanized silica gel can chromatographically separate tetrahydrofuran from diethyl ether (ref. 117). The analogue from 2,6-dlphenylphenol can complex gaseous formaldehyde and prevent its polymerisation (ref. 118). 

A recently developed thin-layer electrophoresis system which employs silanized silica gel with a 1-octanol surface coating as support, and aqueous borate as buffer, has been examined for the separation of mono-, oligo-, and poly-saccharides as well as phenolic compounds and other degradation products from the hydrolythermolysls of biomass. As expected, mobility depended upon the ability to complex... 

Silanized silica gel has also been studied for the SEC analysis of cellulose trinitrate (37,38), using THF as the eluant. It was concluded that the elution behavior of the cellulose trinitrate sample was influenced by polyelectrolytic effects and was not based strictly upon size exclusion. The addition of 0.01 mol acetic acid per liter THF suppressed the non-size exclusion effects. Under these conditions, a universal calibration curve relating cellulose trinitrate and polystyrene could be established. 

Silanized silica gel is stable against aggressive reagents and in addition to those reported in the section Chromatographic paper , the following... 

Figure 2 Thin-layer electrophoresis of uronic acids on silanized silica gel, pretreated with octanol-1 in 0.07 mol I barium acetate solution. Electrophoresis 400V, ISOmin, 16°C. Lanes (1) galactu-ronic acid, (2) mannuronic acid, (3) glucuronic acid, (4) hydrolysate of gum arable (glucuronic acid), (5) hydrolysate of sodium alginate (mannuronic and guluronic acids), (M) mixture of (1-3) and guluronic acid, (H) omega-hydroxymethylfurfural. Sample loading 10 pg of each individual compound. Visualization with naphthoresorcinol-sulfuric acid. Origin indicated.

Separation of acid and neutral polysaccharides, e.g., those of food hydrocolloids (thickening agents, e.g., guar, gum arabic, carrageen, etc.) and pectins. The best supports are silanized glass fiber paper or silanized silica gel-l-octanol. 

Mono- and oligosaccharides can be easily separated on silanized glass fiber paper and on silanized silica gel-l-octanol plates. Both systems offer, as a rapid screening method, an alternative to thin-layer chromatography especially for a clear identification of uronic acids in a mixture with neutral monosaccharides, as it occurs in the case of hydrolysates of acid... 

Mono- and oligosaccharides. Silanized silica gel (for thin- 0.3 mol 1 Borate buffer, pH 1,3-Dihydroxynaphthalene-... 

B 0.3 mol r Sodium borate (EDTA), pH 10 Silanized silica gel-1-octanol 400V(20Vcm ) D-Glucose... 

Amino acid and abbreviation SUica gel G Microcrystalline cellulose Fixion 50-X8 (Na+) Silanized silica gel + 4% HDBS vi... 

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