Solvent compatible

Solvent compatibility Good Very good Very good Good... 

In this context, the enantiomeric pair containing the eutomer of cyclothiazide can be resolved by HPLC on cellulose-derived coated CSPs. Nevertheless, the poor solubility of this compound in solvents compatible with this type of support makes this separation difficult at preparative scale. This operation was achieved with a cellulose carbamate fixed on allylsilica gel using a mixture of toluene/acetone as a mobile phase [59]. 

Extractions and separations in two-phase systems require knowledge of the miscibilities and immiscibilities of ILs with other solvents compatible with the process. These are most usually IL/aqueous biphase systems in which the IL is the less polar phase and organic/IL systems in which the IL is used as the polar phase. In these two-phase systems, extraction both to and from the IL phase is important. 

A methyl group can be placed on cobalt in dicyano[cobyrinic acid heptamethyl ester] when it is treated with excess methyl magnesium iodide (the ester side chains being converted into tertiary alcohol groups). The alkylation could also be achieved using lithium alkyls (176). Presumably this reaction would be successful with any corrinoid which is soluble in solvents compatible with Grignard reagents. 

Two major types of stabilization mechanisms are described for submicron particles (1) charge stabilization, where surface charge forms a repulsive screen that prevents the particles from flocculation, and (2) steric stabilization, where a surface repulsive screen is formed by solvent-compatible flexible polymeric chains attached to the particle s surface. 

Apart from paints, electrokinetic separations find limited application for synthetic polymers [905], mainly because of solvent compatibility (CE is mostly an aqueous technique) and competition of SEC (reproducibility). Reasons in favour of the use of CE-like methods for polymer analysis are speed, sample throughput and low solvent consumption. Nevertheless, CE provides some interesting possibilities for polymer separation. Electrokinetic methods have been developed based on differences in ionisation, degree of interaction with solvent constituents, and molecular size and conformation. 

Need for optimisation (solvent compatibility, flow-rates, peak broadening, etc.)... 

BioEPR samples are generally (frozen) aqueous solutions since water is the only solvent compatible with terrestrial life. The high-frequency dielectric constant of ice is circa 30 times less than that of water. As a consequence liquid-phase EPR is experimentally rather different from frozen-solution EPR. We start with a discussion of sample handling for low-temperature experiments. 

In order to make the Biginelli protocol amenable to an automated library generation format, utilizing the integrated robotic interface of the instrument, attempts were made to dissolve most of the building blocks used in solvents compatible with the reaction conditions. Since many of the published protocols employ either ethanol or acetic acid as solvents in Biginelli-type condensations, a 3 1 mixture of acetic acid... 

The mobile phase in HPLC is called the eluent and is a liquid or a mixture of liquids. Common eluents are water, aqueous solutions, acetonitrile, and methanol. Almost any other common solvent compatible with the column packing and the detector may be used. In some cases, the HPLC instrument will be capable of making a mixture of eluents or changing the mixture of eluents during chromatography. If this is done, care must be taken to make sure that the eluent mixture is compatible with the detector. 

In an effort to optimize the solvent-containing passive sampler design, Zabik (1988) and Huckins (1988) evaluated the organic contaminant permeability and solvent compatibility of several candidate nonporous polymeric membranes (Huckins et al., 2002a). The membranes included LDPE, polypropylene (PP), polyvinyl chloride, polyacetate, and silicone, specifically medical grade silicone (silastic). Solvents used were hexane, ethyl acetate, dichloromethane, isooctane, etc. With the exception of silastic, membranes were <120- um thick. Because silicone has the greatest free volume of all the nonporous polymers, thicker membranes were used. Although there are a number of definitions of polymer free volume based on various mathematical treatments of the diffusion process, free volume can be viewed as the free space within the polymer matrix available for solute diffusion. 

A high-performance liquid chromatography system can be used to measure concentrations of target semi- and nonvolatile petroleum constituents. The system only requires that the sample be dissolved in a solvent compatible with those used in the separation. The detector most often used in petroleum environmental analysis is the fluorescence detector. These detectors are particularly sensitive to aromatic molecules, especially PAHs. An ultraviolet detector may be used to measure compounds that do not fluoresce. 

Fig. 11.8. Some strategies used in commercial API ion sources to increase solvent compatibility and system robustness. Some of these designs are exclusive of particular commercial brands Pepperpot, Crossflow, and LCZ (Micromass) AQA (Thermo Finnigan). Reproduced from Ref. [63] by permission. John Wiley Sons, 1999.

Suppressor Source Continuous Solvent compatible Capacity Regeneration mode Ion type Regenerant source... 

Arborol Dendrimers. The spherical topology of dendrimers resembles the size and shape of the Hartley model (1936) of a micellar aggregate formed by surfactant molecules (Fig. 11.2 Tomalia et al. 1990). Micellar stmctuies have a dynamic, spherical structure possessing a close-packed, solvent-incompatible core surrounded by an open, solvent-compatible layer. 

Analytical Method Development. From the point of view of sorbent selection, the important factors to consider in analytical method development are sorbent/solvent compatibility and the detection limit of the analyte. 

Furthermore, additional positions for further derivatization are available. Solubilizing groups can be attached to the alkyl bridge, further increasing solvent compatibility, whereas N-alkylation allows the facile introduction of substituents, ranging from completely nonpolar to ionic [53]. 

Carbon paste Lightly polished Very low background, easily renewable, reproducible Slow kinetics for some systems, limited solvent compatability Widely used for aqueous oxidations, easy to modify 1... 

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