Hydrogen chromatographic absorbent

Hydrogen-Deuterium Exchange of H20s C0) q and H Ee CO) on Florisil Chromatographic Absorbent... 

This presentation covers some of the basic data and derived results are discussed. The gases species of oxygen, carbon monoxide and carbon dioxide and nitrous oxide have been measured for all the tests. In the full scale fire tests hydrogen chloride and hydrogen cyanides were measured. Hydrocarbons and their relative abundance were determined by collecting gas samples on absorbent tubes for later analysis on a gas chromatograph and a mass spectrometer. 

Solutions of 1.0 M hydrogen peroxide in acetonitrile and 4.45 mM trichlorophenol (TCP) in ethyl acetate were used as postcolumn reagents, with the flow rates optimized at 1.0 ml/min each. The chromatographic eluent ranged from 70 to 80% acetonitrile-4 mM sodium phosphate buffer at apparent pH 7.5. The absorbance and fluorescence wavelengths for coumarin tags were as follows ... 

Firestone et al. (54) heated cottonseed oil at 205° and 225°C in the presence of air. The dimers and higher polymers that were isolated contained moderate amounts of carbonyl and hydroxyl groups and unsaturation difficult to remove by hydrogenation. However, the dimers after bromination-dehydrobromination and oxidation absorbed in the UV region at 250-260 nm and 270-280 nm, indicating the presence of cyclic structures. In addition, Barrett and Henry (55) presented chromatographic and spectral evidence for the presence of dimers in cottonseed oil that had been used for frying. 

Another method of direct determination of organic sulfur is to subject a small (20- to 30-mg) sample of <200-mesh coal to low-temperature ashing 1 to 3 hours and to collect the sulfur oxides evolved in a cold trap. They are then absorbed in hydrogen peroxide (H202) and determined chromatographically. 

The solution of 3.0 g thereof in 30 ml of glacial acetic acid is hydrogenated over 100 mg of platinum oxide at 2.7 atm and room temperature until the theoretical amount of hydrogen has been absorbed. It is filtered, the filtrate evaporated, the residue taken up in methylene chloride-diethyl ether and the solution washed with saturated aqueous sodium bicarbonate. It is dried, evaporated, the residue chromatographed on 30 g of silica gel and eluted with methanol-chloroform (1 9), to yield the ll-(N-methyl-N-benzylaminomethyl)-10,ll-dihydro-5H-pyrrolo[2,l-c][l,4]benzodiazepine melting at 147°-149°C. 

The techniques used by VeSefa [49] for the automatic microdetermination of carbon and hydrogen in organic compounds do not differ from the chromatographic method, except that chemical absorbers are used instead of the chromatographic column as a result, it is possible to detect only one product. An original sample of 1.0-1.6 mg was mixed with 30—40 mg of mixed oxides of cobalt and rapidly combusted in a quartz tube containing an appropriate catalyst. 

This reaction can be regarded as a version of the chemical amplification method, because three molecules of hydrogen are produced per molecule of carbon monoxide. The water is absorbed by molecular sieves. This method appears to be highly suitable for the continuous analysis of oxygen-containing compounds following chromatographic separation. 

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