Incompatibility problems

The different food products discussed below illustrate compatibility/ incompatibility problems and solutions in flexible packaging. 

Aqueous two-phase hydrogenation may be a method of choice for synthetic purposes when no incompatibility problems between water and the substrates, products, or catalyst arise. It has already been proven by the success of the Ruhrchemie-Rhone-Poulenc hydroformylation process, that the catalyst can be retained in the aqueous phase with very high efficiency, and that aqueous-organic biphasic processes using organometallic catalysts are suitable for indus-... 

One of the principal factors to be considered is the concentration of pigment m the dispersion concentrate. Compatibility of the carrier (solvent additives, etc) used in the preparation of concentrated dispersion and that used in the finished color product also plays an important role. In some cases this can be difficult because the earners having the best performance, from the standpoint of processing, could be poor in the application systems. However, in the majority of the applications, particularly in coatings and colored plastics, the concentration of the pigment in the finished product is quite low. and the incompatibility problem is easily overcome. 

The use of a two-phase system with added phase transfer catalyst and the use of a microemulsion are two alternative approaches to overcome reagent incompatibility problems in organic synthesis. Both routes have proved useful but on entirely different accounts. In phase transfer catalysis the nucleophilic reagent is carried into the organic phase where it becomes highly reactive. In the microemulsion approach there is no transfer of reagent from one environment to another the success of the method relies on the very large oil-water interface at which the reaction occurs. 

An awareness of crystal packing characteristics and polymorphism helps one to understand incompatibility problems of different fats. Crystal formation has specific demands, and individual crystals in mixed systems each consists of only one species ofTAG. However, surfactants and other molecules can act as impurities and interrupt crystal growth. Different TAG are considered compatible when they co-crystallize as separate crystals under the same conditions without the formation of a eutectic. 

An awareness of crystal-packing characteristics and polymorphism helps one to understand incompatibility problems of different fats. Polymorphism has several industrial implications in use of fats as shortenings, margarines, and cocoa butter. 

Although excipients are the non-active ingredients, they are indispensable for the successful production of acceptable solid dosage forms. The important roles played by excipients in tablets and capsules, freeze-dried, and spray-dried powders, as well as powder aerosol formulations, were discussed. Some recent applications of excipients in controlled, release formulations for biologicals were also highlighted. Finally, incompatibility problems attributable to excipients were considered with an emphasis on the indirect role of excipients through moisture distribution. 

Has any new software been installed recently New software can mean incompatibility problems with existing problems. This is especially true for Windows programs. A new Windows program can overwrite a required DLL file with a newer version of the same name, which an older program may not find useful. 

Containment sound design of equipment and piping, to avoid leaks. For example, specifying welded joints in preference to gasketed flanged joints that are liable to leak or suffer materials incompatibility problems. 

List the materials incompatibility problems you should be aware of in plants that handle... 

The most appropriate way to solve mobile-phase incompatibility problems in LC-MS is to change the mobile-phase composition to LC-MS compatible conditions. This is the approach taken in most cases. Unfortrmately, it is not always possible to do so. In some cases, specialized LC colunrn materials demand a particular mobile-phase composition. This is the case with for instance some chiral colunms, which will only provide adequate enantiomeric separation in a predefined mobile phase. The retention behaviour in high-performance anion-exchange chromatography (HPAEC) is significantly influenced by the cation (sodium or ammonium) in the mobile phase. In these cases, mobile-phase... 

When two dissimilar plastic foams are to be joined, which is rarely done, adhesive bonding is generally preferable because of solvent and polymer incompatibility problems. Solvents used to cement plastics should be chosen with approximately the same solubility parameter (5) as the plastic to be bonded. The solubility parameter is the square root of the cohesive energy density (CED) of the liquid solvent or polymer. CEDs of organic chemicals are primarily derived from the heat of vaporization and molecular volume of the molecules, and are expressed as calories per cubic centimeter (cal/cm ). Literature sources provide data on 6 s of a number of plastics and resins (2) (3) (4). 

There are various options to overcome the reagent incompatibility problem. One way is to use a solvent or a solvent combination capable of dissolving both the organic compound and the inorganic salt. Polar, aprotic solvents, such as dimethylsulphoxide (DMSO), dimethylformamide (DMF) and tetrahydrofuran (THF), are sometimes useful for this purpose but many of these are unsuitable for large-scale work due to toxicity and/or difficulties in removing them by low vacuum evaporation. 

The development of virtual machines reduces the problems of incompatibility in an automated system, especially when the automated equipment follows different communication standards and protocols. It also enables the high-level controller to focus on his or her control activities, such as sequencing and scheduling, rather than detailed command incompatibility problems. Further information on virtual machines and automation can be found in Burdea and Coiffet (1999). 

Cai Wen. 1983. So ution of incompatible problems via structural transformation. Gdit journal, 1 76-88. 

Solving incompatibility problems by separating APIs from each other or carrier materials. 

In terms of liquids from coal that can be integrated into a refinery, this represents the most attractive option and does not threaten to bring on incompatibility problems as can occnr when phenols are present in the coal liquids. 

Recently, Veith and Cohen (3) analyzed nylon 6 in TFE using the universal calibration method and peak retention data from narrow PMMA fractions. Silanized silica columns obviate the solvent incompatibility problem of TFE with styrene-based packings and give reproducible results. The accuracy of the calculated nylon 6 molecular weights was cross-checked with an independent end-group analysis (for M ) and intrinsic viscosity measurement (forMJ. 

In order to avoid the loss of analyte, either as much of the LC effluent as possible has to be introduced into the mass spectrometer, or efficient analyte enrichment must be achieved in the LC-MS interface. Without modification, only 50nls of liquid can be introduced into a differentially pumped MS vacuiun system. Possible solutions to this flow-rate incompatibility problem are enlargement of the pumping capacity of the MS vacuum system, removal of solvent prior to the introduction of the analytes into the high-vacuum region, splitting away part of the effluent at the cost of analyte loss, and miniaturization of the internal diameter of the LC column. The currently applied interface, based on atmospheric-pressure ionization (API), is discussed in more detail below. 

Incompatibility problems with organic and inorganic spherical fillers in plastics may be overcome by grafting reactive groups on their surface or adding coupling agents. 

---