Nitrate column

The Th fraction is collected in a Teflon beaker by eluting the column three times with 9 mol/L HCl (filled to the top). 

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Organic solvents or mixtures of water and solvents such as acetone or water-acetone are commonly used to extract chemicals from sediment samples as for upland soil. An analysis of sediment, collected from waterways or extremely low Eh paddies, frequently requires the removal of sulfur-containing species, although there is little interference from sulfur if the sediments are in a not very reductive condition. Reduced copper and silver nitrate columns are usually used for the removal, but these procedures are not always successful. Recovery studies could be needed to confirm an interference with sulfur. 

McIntyre et al. [58, 59] described a method for the analysis of polychlorobiphenyls and chlorinated insecticides in sewage sludges in which homogenized samples are extracted with hexane, concentrated and cleaned up on an alumina/alumina plus silver nitrate column and eluted with hexane. After concentration of the eluent, polychlorobiphenyl and organochlorine compounds were determined by a silica gel chromatographic procedure and gas chromatography. 

Density measurements were made at 23 °C on spherical neat resins of 5 mm diameter using the flotation method in accordance to ASTM D-1505. The density gradient column (Model DC-1) was supplied by Techne Incorporated, Princeton, New Jersey. Calcium nitrate column was set up which could measure density accurately ranging from 1.210 to 1.290. 

Light hydrocarbon products were analyzed with a P E F-ll gas chromatograph with a benzyl cyanide-silver nitrate column and flame ionization detector. No effort was made to recover and analyze heavy hydrocarbons. 

All of the enzymes with substitutions at His-357 and His-391 precipitated at the same ammonium sulfate concentrations, and eluted from the ion exchange and gel nitration columns in similar volumes as wild type. This indicated that the physical properties associated with purification (aggregation, quaternary structure, charge, etc.) were not affected by the mutations. The enzymes were greater than 95% pure as analyzed by SDS PAGE. H357F was stable for at... 

Gas chromatography using dimethylsulfolane on Chromosorb P did not separate trans-2-hexene and cis-3-hexene. That both were present at higher conversions was established by chromatography on a silver nitrate column. 

Fig. 2.2. Chromatograms of 1,3-pentadiene on a composite column containing silver nitrate (column 1) and a column reactor containing chloromaleic anhydride (column 2) at40°C [64]. Carrier gas (helium) flow-rate (A) 77ml/min (B) 11.4ml/min. First peak area (trans isomer) (A) 60% (B) 31%. From ref. 64.

A thallium nitrate column is stable for several weeks at 100°C and can be used for 180h at 130°C without selectivity loss. A silver nitrate colunm can be used for 180h only at 60°C. Unfortunately, the efficiency of columns containing thallium salts is lower than that of silver salts. 

Mobile phase MeOH water trichloroethanol 23 75 2, all 0.1 M in silver nitrate Column temperature 45 Flow rate 1.0... 

Column A 30 X 2.1 Spherisorb Cl pH stable B 150 X 2.1 Spherisorb Cl pH stable Mobile phase 5 mM pH 7.3 Tris-nitric acid buffer containing 0.1% Tween 20 and 150 mM sodium nitrate Column temperature 40 Flow rate 0.2 Injection volume 50 Detector UV... 

Cyclohexane forms explosive mixtures with air within the range 1.3-8.4% by volume in air. Its reactivity is very low. An explosion has been in record when liquid nitrogen dioxide was mixed accidentally with hot cyclohexane in a nitration column (MCA... 

Evaporate the eluate from the chloride column under an IR lamp. Dissolve in 8 mol/L HNO3 and run a nitrate column (Section 13.7.6). Collect the 8 mol/L HNO3 eluate in a polypropylene bottle (Pb fraction). Repeat the nitrate column if the sample is not clean enough (Section 13.7.6). 

Calibration Add 1 mL (ThVol) of spike to a weighed aliquot of the U stock solution (activity Uact, approximately 60dpm) in a small Teflon beaker. Warm, evaporate to dryness under an IR lamp, take up in 9 mol/L HO, separate Th from U by passing through a chloride column (Section 13.7.5 note time-of-separation), purify Th on a nitrate column (Section 13.7.6) and electroplate (Section 13.7.7). Count in alpha and beta counters. Calculate the calibration factor ... 

Take up in 9 mol/L of HQ and proceed as for the Th determination (Section 13.8.1) with the chloride and nitrate columns. Collect the eluate of the nitrate column in a polypropylene bottle (Pb fraction). 

The alkali metal nitrate columns had a greater retention order than that of the corresponding alkali metal chloride columns. 

The lOO.OOOg supernatant obtained from the extract showed a diterpene cyciase activity. The resulting olefinic product was identified by radio-GLC and argentation liquid chromatography. This compound has the same retention time on GC, as weli as on silice-sllver nitrate column, as 7,13-abietadiene (standard marker synthesized by reduction of abietic acid). 

Silicic acid-silver nitrate columns (Barrett et al., 1962 De Vries, 1962, 1963,1964 Hirsch, 1961) have shown some advantage over the other techniques as a preparative tool of relatively high quantities of glycerides of similar unsaturation to be used for further resolution. Resolutions according to molecular weight occur on factice, a polymerized oil partition columns have had very limited use (B. C. Black and Hammond, 1963 Trowbridge et al., 1964). 

XI. 1.2 Benzyl Cyanide-Silver Nitrate Column—This column separates isobutane, n-butane, the butenes, n-pentane and isopentane, and accordingly is best suited for use with LP gas butane containing unsaturated C4 hydrocarbons. 

Note XI.2 Warning—toxic. Precaution—See the product safety bulletins from the supplier of the chemicals used in preparing these columns or before Benzyl Cyanide-Silver Nitrate Column X1.1.3 Hexamethylphosphoramide (HMPA) column, and XI. 1.4 Dimethylsufolane (DMS) Benzyl Cyanide-Silver Nitrate Column. 

A new remarkable side chain alkylation pattern has been found in calysterol, the principal sterol component of the sponge Calyx nicaensis 75a). Structure (181), reminiscent of those of gorgosterol (175) and its relatives (176) and (177), has been proposed for this unique sterol on the basis of spectral data (m.s. and n.m.r.) of the acetate, m.p. 105—106°, [a]o-34.3°, and Lemieux oxidation of the corresponding stanol to a p-diketone (182). Interestingly, calysterol (181) completely decomposes on an alumina-silver nitrate column to give four compounds the major one has been characterized as (182 a). 

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