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Degassers, solvent

The effect of the mobile-phase composition on the operation of the different interfaces is an important consideration which will be discussed in the appropriate chapter of this book but mobile-phase parameters which affect the operation of the interface include its boiling point, surface tension and conductivity. The importance of degassing solvents to prevent the formation of bubbles within the LC-MS interface must be stressed. [Pg.30]

Caution BINAP-Ru complexes are rapidly oxidized in solution in the presence of air and all procedures should be carried out under anaerobic conditions using degassed solvents. [Pg.137]

For the synthesis of carbohydrate-substituted block copolymers, it might be expected that the addition of acid to the polymerization reactions would result in a rate increase. Indeed, the ROMP of saccharide-modified monomers, when conducted in the presence of para-toluene sulfonic acid under emulsion conditions, successfully yielded block copolymers [52]. A key to the success of these reactions was the isolation of the initiated species, which resulted in its separation from the dissociated phosphine. The initiated ruthenium complex was isolated by starting the polymerization in acidic organic solution, from which the reactive species precipitated. The solvent was removed, and the reactive species was washed with additional degassed solvent. The polymerization was completed under emulsion conditions (in water and DTAB), and additional blocks were generated by the sequential addition of the different monomers. This method of polymerization was successful for both the mannose/galactose polymer and for the mannose polymer with the intervening diol sequence (Fig. 16A,B). [Pg.232]

Olefin Metathesis in Non-degassed Solvent Using a Recyclable, Polymer Supported Alkylideneruthenium, J. Dow-DEN, J. Savovic, Chem. Comm. 2001, 37-38. [Pg.502]

Caution Since DAiB deteriorates in air, bottles of DAIB should be flushed with N2 or Ar and kept tightly closed for storage over long periods. Diethylzinc easily catches fire upon contact with air or moisture and additbn to benzaidehyde should be performed under anaerobic conditions using degassed solvent. [Pg.217]

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. [Pg.182]

All reactions and manipulations should be performed under an atmosphere of dry nitrogen either in a dry box or using Schlenk tube techniques. Filtered and degassed solvents should be used for the chromatographic separations. [Pg.162]

All manipulations are carried out under nitrogen using freshly degassed solvents. The triphenylphosphine should be recrystallized from hexane before use. [Pg.201]

Mechanistic Experiments. Sample solutions of [Mo -CsHs ] and [Mo(r75-C5H5)2D2] were prepared by distilling appropriate degassed solvent into Schlenk tubes that contained the complex. Tne sample solutions were subjected to short-term photolysis (<5 min) in a 350-nm Rayonet reactor. The solutions were frozen immediately after photolysis, and the mass spectrum of the gases above the frozen solutions was recorded. [Pg.205]

Caution. Sulfuric acid containing 30% S03, filming sulfuric acid, is a severe caustic irritant product. Avoid any contact. All the reactions must be performed under an atmosphere of argon using standard Schlenk techniques and degassed solvents and reactants. [Pg.37]

Boger and co-workers have studied the intramolecular Ullmann reaction extensively. Some representative examples are shown in Table 3. For substrates in which the N10 site is not methylated, the reaction is complicated by intramolecular N-acylation of the N10—Cu amide by the C12 carbamate. In some cases, the generation of this byproduct could be suppressed by using freshly dried and degassed solvent with purified CuBr-DMS complex. 10 However, in other cases, the byproduct was still produced and the yield of the desired product suffered accordingly. 27 ... [Pg.201]

Treatment 1 Open a purge valve. Prime the pump with degassed solvent. [Pg.222]

Other common practices include the use of well-degassed solvents, low concentrations of electrolytes, a relatively large amount of the organic component in the mobile phase, working at reduced temperatures (e.g., 15°C) when possible, and the use of low conductivity electrolytes (i.e., zwitterionic buffers). The addition of sodium dodecyl sulfate (SDS) into the mobile phase at low concentrations has also been used to minimize bubble formation [67]. [Pg.153]

Degassing Solvents from Synthetic Rubber (Styrene-Butadiene Compounds)... [Pg.195]

Although the use of ultrasound to assist sample preparation has so far been limited in relation to its potential [39,40], few analytical chemists are unaware that US can help, improve, aoeelerate or automate the preliminary steps of the analytical process — particularly those preoeding sampling (e.gf. cleaning the lab material or degassing solvents). Ultrasound has also found a variety of uses in the detection step ranging from... [Pg.31]


See other pages where Degassers, solvent is mentioned: [Pg.12]    [Pg.350]    [Pg.80]    [Pg.99]    [Pg.510]    [Pg.338]    [Pg.252]    [Pg.486]    [Pg.23]    [Pg.71]    [Pg.96]    [Pg.67]    [Pg.244]    [Pg.18]    [Pg.191]    [Pg.496]    [Pg.12]    [Pg.132]    [Pg.185]    [Pg.469]    [Pg.1036]    [Pg.54]    [Pg.1228]    [Pg.314]    [Pg.44]    [Pg.87]    [Pg.113]    [Pg.127]    [Pg.406]   
See also in sourсe #XX -- [ Pg.102 ]




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