Methyl silicone gum

The products of the oxidation reaction were analysed by gas chromatography (Hewlett Packard, 5880 A), employing a FID detector and equipped with a capillary column (50 m x 0.25 mm crosslinked methyl silicone gum). The reactants and products of n-hexane oxidation were analysed by gas chromatography (Hewlett Packard, 5890) equipped with a FFAP column (30 m X 0.25 mm). The identity of the products was further confined by GC-MS (Shimadzu QCMC-QP 2000A). 

The third technique we used was a measurement of changes in the sorption behavior of a compound in the presence of humic materials. A thin film of OV-1, a methyl silicone gum used as a chromatographic stationary phase, was plated on the bottom of a 60 ml Hypo-Vial (Pierce Chemical Co., Rockford, 11.). A solution of radiolabeled pollutant was added to the vial in either buffered distilled water in a solution of humic materials. Again, it is assumed that the pollutant is solution consists of two fraction free and bound. It is also assumed... 

For a nonpolar column (or equivalent) methyl silicone gum, or equivalent (preferably a bonded and cross-linked dimethyl polysiloxane) ... 

Substrate Hexadecane (Cl 6) Tetracontane (C40) Paraffin Wax (C20-C60) Carbowax (15M) Microwax Methyl Silicone Gum (SE-30) Polyethylene Glycol (MW 2000)... 

Composition (weight %) by gas chromatography of a super unleaded gasoline, with RON 98.2, MON 86.2. Shown in order of elution from a methyl silicone gum capillary column. 

The oxidation of thioethers was carried out in a glass flask equipped with a condenser, a magnetic stirrer and a thermometer. In a typical reaction, TS-1 (40 mg) or Ti-beta (50 mg) was stirred with sulfide (2 mmol), the solvent (10 ml), H2O2 (2 mmol) at a constant temperature. The products were analyzed using a GC, equipped with a capillary column (Methyl Silicone Gum, 25 m x 0.2 mm x 0.33 pm Film thickness). The hydrogen peroxide was measured by standard iodometric titration. 

The hydroxylation of phenol was carried out using aqueous H2O2 (30 wt.%) as oxidant. In a standard run, 5 g of phenol, 10 g of water, 0.5 g of catalyst and 2.13 g of H2O2 (phenol/H202 mole ratio = 3) were taken in a 50 mL glass reactor and heated to 353 K in an oil bath for 10 h. The products were analyzed by GC (HP, 5880A) equipped with a 50 m long methyl-silicon gum capillary column and flame ionization detector. 

A typical reaction was carried out in a small flask. A mixture of catalyst (Ig), naphthalene (0.023 mole), benzyl chloride (0.011 mole) and 1,2-dichloroethane (15g) was stirred at the required temperature for 18h. The courses of the reaction was followed by gas chromatograph (Blue Star Model 421) fitted with flame ionization detector and a capillary column (50m x 0.2mm) with methyl silicone gum. Some selected runs were analysed by GC-MS (Shimadzu-MS QP-2000A). The composition of the reaction mixture was determined by comparing their gas chromatographs with those of the authentic samples. 

Figure 1. GC-MS total ion chromatogram of onion extract, obtained by using a 30 m X 0.53 mm methyl silicone gum capillary column, injector and column programmed from 0 to 200 °C. Peak identification l-MeS(0)SMe 2-MeS(0)SPr-n 3-(E,Z)-MeCH=CHSS(0)Me 4-MeSS(0)Pr-n 5-( )-Me-CH=CHS(0)SMe 6-( ,Z)-MeCH=CHSS(0)Pr-n, fran -zwiebelane (9a) 1-cis-zwiebelane (9b).

Chromatographic column a stainless steel column (5ft x ginch o.d.) packed with 5% by weight of General Electric SE-30 (methyl silicone gum rubber) on 60/80 mesh Chromosorb W. This column did not cause significant decomposition of ferrocene derivatives. The column was preconditioned at 250°C for 72 hours prior to use. 

Liquid Phase for Columns—Methyl silicone gums and liquids provide the proper chromatographic hydrocarbon elution characteristics for this test method. 

Fatty acids Ethylene glycol succinate (EGS) Methyl silicone gum rubber SE-30 Methyl esters... 

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