Atmospheric techniques

The detection of hydrocarbons above the ground surface offers obvious advantages continuous sampling, no permit requirements, access over rough and hostile 

The microwave approach has been developed by Owen (1972), Goumay (1979) and Thompson (1981). Although Thompson (1981) has stated that conclusive proof does 

The third atmospheric technique analyses the residual liquid and/or condensate hydrocarbon traces on aerosols carried into the atmosphere by thermals (Barringer, 1981). The aerosols are created by gas bubbles which exsolve into the atmosphere from the sea in areas where microseeps create gas bubbles which reach the sea surface. The aerosols are concentrated from large volumes of air and collected by an airborne cyclone sampler carried aboard an aircraft which is flown at 30 m (100 feet) above the sea surface. Hydrocarbons adsorbed on the aerosols are measured by a flame ionisation detector which yields a total hydrocarbon signal. This system is claimed to produce 

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Crystallography. The crystal was transferred to the goniostat using inert atmosphere techniques. 

Bis(r78-cyclooctatetraene)uranium(IV) and its precursor, dipotassium cyclo-octatrienediide, are air and water sensitive. A knowledge of inert-atmosphere techniques is essential to conduct this synthesis successfully.7 ( Caution. Dry dipotassium cyclooctatrienediide may react explosively with air therefore it always should be handled under an inert atmosphere or in vacuum.)... 

All manipulations are conducted by using appropriate inert-atmosphere techniques. Toluene and THF are refluxed over sodium benzophenone and MeOH over Mg and then distilled prior to use. The ligands SalenH2 and Salen BuH2 were synthesized as described previously. Dimethylaluminum chloride is available from Aldrich Chemical Co. 

Caution. CuCN is corrosive and toxic, so protective clothing should be worn when handling it. The procedure should be performed using standard inert-atmosphere techniques and degassed solvents. 

All synthetic manipulations are carried out using standard vacuum or inert atmosphere techniques as described by Shriver.8... 

All manipulations are carried out using inert atmosphere techniques.8 Solvents must be distilled from sodium-benzophenone ketyl. Borazine is prepared by the procedure described above. 

Equipment. All manipulations were performed under inert atmosphere conditions. Standard vacuum line and inert atmosphere techniques were employed.5 Reactions were conducted using glassware with solvseal joints. Glassware with ground glass joints could not be used as these joints were prone to leak at low temperature or when solvent dissolved the vaccum grease. 

F. Molecular Weight Determinations. In principle, any standard method of molecular weight determination may be adapted for use under air-free conditions, and those which involve inert-atmosphere techniques have been covered in Section I.5.F. This section will cover molecular weight determinations which require the use of a vacuum system. 

The observed lines gives the stellar photospheric abundance via the standard stellar atmospheric technique. For stars with a surface temperature T > 5500 K and a metallicity less than about l/20th the solar metallicity, the abundances pratically show no dispersion (the famous lithium plateau for such stars.)... 

Lithium tetrahydridogallate, which was first prepared by Finholt, Bond, and Schlesinger,1 is a very useful starting material for the preparation of gallium hydride derivatives.2-3 The present synthesis is based on an adaptation of the original preparation.1-4 Since gallium-hydrogen bonds are susceptible to hydrolysis, it is necessary to perform the preparation in the absence of air. The procedure described is based on the use of Schlenk-type inert-atmosphere techniques. 

The complexes reported below were made earlier by bridge-splitting reactions on [Co(NO)2X]2. Although this dimer is an isolable intermediate in the procedures reported here, it is best prepared by reduction of C0X2 in the presence of excess Co. However, the following preparations represent the most convenient route to a variety of base adducts of the form Co(NO)2L2+. Since all these compounds and intermediates are more or less air-sensitive, operations should be carried out using standard inert-atmosphere techniques. Caution. Because of the toxicity of NO, the following reactions must be performed in a well-ventilated hood. 

Preparatiou. The reagent is best prepared by a modification of the original procedure of Wilke. The preparation involves reduction of nickel acetylacetonate (Alfa Inorganics) with triethylaluminum (Texas Alkyls) in the presence of 1, S-cyclooctadicne. Because of the sensitivity of Ni(COD)> to oxygen, special inert-atmosphere techniques mu.st be used. The yield is 81 %. 

The use of Cp2TiCl2 as a colorimetric indicator for inert atmosphere techniques through the synthesis of the titanium(ni) complex [Cp2Ti(NCMe)2]+ has been described.1135... 

The inert atmosphere technique and the time required outside the laboratory for column chromatography increase the difficulty of this experiment. 

The inert atmosphere technique requires dedicated patience. 

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