Organic solvent addition

The yield of CDs could be enhanced by adding appropriate organic solvent in the system. Chen et al. reported that the yield of CDs increased about 100% when adding 10% of ethanol [20]. Several water-insoluble organic solvents such as decane and toluene can also be used to increase the yield of CDs as described in Sec. 3.1.1.2. However, those solvents are prohibited for CD production when CDs are used in food because of the toxicity. 

---

Because of their polymeric forms, alkylenebis(dithiocarbamates) are insoluble in water and most organic solvents. Additionally, they form strong complexes with different metal ions No extraction and chromatographic procedure has been reported for the parent compound of this chemical class. These compounds decompose readily under acidic conditions, for example by contact with the fruit or plant juice generated during sample preparation. 

AtCCD7 (Schwartz et al. 2004). Organic solvent addition (dioxane, DMSO, methanol or acetone) improved activity under low concentrations (Mathieu et al. 2007). Short chain aliphatic alcohols activated the enzymes although the reason for this activation is unclear (probably due to influences on substrate accessibility or micellar structure). An increase in activity was observed for all aliphatic alcohols tested, although the optimal concentration lessened with increasing log P values (Schilling etal. 2007). 

The patent described a method for the removal of thiophenic compounds from fossil fuels, in which the reacting media might contain organic solvents. Additionally, the biocatalyst may be contacted with the fuel directly either as free enzyme or in its immobilized form. The process could, therefore, be performed either in a batch reactor or in a semi-continuous or continuous manner. Further, it may be performed either as a stand... 

Dissolve SPDP in dimethylformamide (DMF) at a concentration of 6.2 mg/ml (makes a 20 mM stock solution). Add 50 pi of the SPDP solution to the 1 ml particle suspension and mix to dissolve. Note The small quantity of DMF in a polymeric particle suspension should not affect particle stability, even if the polymer type is susceptible to swelling in pure DMF. Other particle types, such as metallic or silica based, usually are not affected by organic solvent addition, unless their surfaces are non-covalently coated with a dissolvable polymer. 

Use of cosolvent. Various cosolvents, such as acetone, ethanol, methanol, hexane, dichloromethane, and water, have been used for the removal of carotenoids using SC-CO2 extraction (Ollanketo and others 2001). All these cosolvents except water (only 2% of recovery) increased the carotenoid recovery. The use of vegetable oils such as hazelnut and canola oil as a cosolvent for the recovery of carotenoids from carrots and tomatoes have been reported (Sun and Temelli, 2006 Shi, 2001 Vasapollo and others 2004). For the extraction without cosolvent addition, the lycopene yield was below 10% for 2- to 5-hr extraction time, whereas in the presence of hazelnut oil, the lycopene yield increased to about 20% and 30% in 5 and 8 hr, respectively. The advantages of using vegetable oils as cosolvents are the higher extraction yield the elimination of organic solvent addition, which needs to be removed later and the enrichment of the oil with carotenoids that can be potentially used in a variety of product applications. 

Avoid using highly concentrated caustic solutions because agents can become insoluble. Any agent that does not dissolve in the aqueous caustic solution will not be hydrolyzed. An agent will also be insoluble if it is dissolved in an immiscible organic solvent. Addition of solvents or mechanical mixing may be required to overcome insolubility problems. 

It tends to occur in organic solvents addition of water reduces the extent of... 

One of the main problems to be solved in the analysis of cationic surfactants is the strong adsorption of the surfactant to glassware, tubing and apparatus. To avoid losses, the solvent system used should contain a substantial percentage of organic solvent. Additionally, mobile phases containing more than 20-25% methanol will help to inhibit micelle formation [46]. 

In order to select the optimal sample diluent that allows adequate detection at low level and good peak shape, investigate the influence of pH, type of organic solvent, percentage of organic solvent, addition of additives (cyclodextrin, surfactants, etc.), injection volume, different counter ions, etc. 

Organic solvents. Addition of organic solvents decreases the solubility of proteins by reducing the dielectric constant of the medium. For the precipitation of enzymes, methanol, ethanol or propanol are mostly used, but acetone and diethyl ether can also be employed. The principal disadvantage of organic solvents is their tendency to cause stmctural damage of enzyme molecule. 

Supercritical fluid extraction uses a supercritical fluid (Box 25-2) as the extraction solvent.20 C02 is the most common supercritical fluid because it is inexpensive and it eliminates the need for costly disposal of waste organic solvents. Addition of a second solvent such as methanol increases the solubility of polar analytes. Nonpolar substances, such as petroleum hydrocarbons, can be extracted with supercritical argon.21 The extraction process can be monitored by infrared spectroscopy because Ar has no infrared absorption. 

However, the use of enzyme labels in ILAs seems to be less practical for a number of reasons. First, they often work only in aqueous buffers as enzymes are more susceptible to inactivation than fluorescent or chemiluminescent compounds under harsh conditions such as organic solvents. Additionally, enzymes are invariably high molecular weight species that diffuse slowly into the MIP cavities and may have a greater tendency to increase the non-specific interactions of some other labels. Accordingly, few enzyme ILAs have been reported to date (Table 4) and, in... 

Prior to metabolomic analysis, sample treatment is typically needed, as CSF contains approximately 0.3 mg/mL protein (114) that may hinder metabolite analysis. Consequently, CSF sample treatment is essentially directed to protein removal by means of organic solvent addition (84,88) or by ultrafiltration (85,89,90). The final metabolic extract composition will depend in a great extent on the sample treatment (115), and it will be selected mostly regarding the metabolomic approach and the analytical technique that will be afterward applied. 

Component/Aqueous Conditions (Ref.) Surfactant/ Organic Solvent Additives/ Co- extractant Comments... 

The dynamic cyanohydrin system was next challenged with lipase-catalyzed transesterification resolution using different operational conditions. Thus, different lipases, organic solvents, additives, and acyl donors were evaluated. Isopropenyl acetate 26 was chosen and used as acyl donor because its reaction produces acetone as by-product, which does not interfere in the reaction and the NMR spectra. Molecular sieve 4 A was also added in the dynamic resolution process to control the water activity. The lipase preparation PS-C I was chosen in the resolution process since it expressed the highest lipase activities for both the substrate structure and the enantiomeric selectivities. Different organic solvents were also... 

Reaction of [PtMe2(COD)] with bromine or iodine yields a polymeric, halide-bridged Pt(IV) species, which is insoluble in organic solvents. Addition of neutral ligands, however, allows conversion to monomeric Pt(IV) complexes ... 

The apparatus is composed of two main parts a temperature regulator, and a programming device for organic solvent addition (Fig. 23) (Balny and Becker, 1971). The regulator is a thermostatted bath (Air Liquide BRT 90) coupled to a C 1319 regulator, which is programmed to cool the bath at various speeds between +20° and — 100°C. 

Sc(() l f) ( is an effective catalyst of the Mukaiyama aldol reaction in both aqueous and non-aqueous media (vide supra). Kobayashi et al. have reported that aqueous aldehydes as well as conventional aliphatic and aromatic aldehydes are directly and efficiently converted into aldols by the scandium catalyst [69]. In the presence of a surfactant, for example sodium dodecylsulfate (SDS) or Triton X-100, the Sc(OTf)3-catalyzed aldol reactions of SEE, KSA, and ketene silyl thioacetals can be performed successfully in water wifhout using any organic solvent (Sclieme 10.23) [72]. They also designed and prepared a new type of Lewis acid catalyst, scandium trisdodecylsulfate (STDS), for use instead of bofh Sc(OTf) and SDS [73]. The Lewis acid-surfactant combined catalyst (LASC) forms stable dispersion systems wifh organic substrates in water and accelerates fhe aldol reactions much more effectively in water fhan in organic solvents. Addition of a Bronsted acid such as HCl to fhe STDS-catalyzed system dramatically increases the reaction rate [74]. 

Colorless primers, water thinnable Primer coatings of mineral basements (e.g. plastering, concrete), up to est. 3 % organic solvents, additional other solvents Not declared... 

Clear lacquers, wood glazings, water thinnable Resin dispersions from water-thinnable alkyd resins, polyurethane resins and polyacrylates, containing 35-85 % water, 5-10 % organic solvents, additional other solvents DEGMB, PGMM... 

---