Solubility groups classification

An outline of the solubility classification procedure is given in Table X 1,5,2, whilst the characteristic features of each of the solubility groups are summarised in Table XI,5,3. 

The imides, primaiy and secondary nitro compounds, oximes and sulphon amides of Solubility Group III are weakly acidic nitrogen compounds they cannot be titrated satisfactorily with a standard alkaU nor do they exhibit the reactions characteristic of phenols. The neutral nitrogen compounds of Solubility Group VII include tertiary nitro compounds amides (simple and substituted) derivatives of aldehydes and ketones (hydrazones, semlcarb-azones, ete.) nitriles nitroso, azo, hydrazo and other Intermediate reduction products of aromatic nitro compounds. All the above nitrogen compounds, and also the sulphonamides of Solubility Group VII, respond, with few exceptions, to the same classification reactions (reduction and hydrolysis) and hence will be considered together. 

After the unknown is assigned to one of the solubility groups (Fig. 2) on the basis of solubility tests, the possible type should be further narrowed by application of classification tests, e.g., for alcohols, or methyl ketones, or esters. 

Determination of the fibre type, including checking of the stated fibre type, is one of the most important preliminary tests. If no IR spectrometer is available, standard fibres can be most readily identified using the characteristic reactions according to Stratmann. For modified fibres or high-performance and speciality fibres the more complicated classification on the basis of solubility groups and their subdivisions or other methods of analysis have to be used. 

Table 8.18 Classification of manufactured fibres in solubility groups (SG) according to Stratmann -...

Classification of vitamins into fat-soluble and water-soluble groups reflects the history of their discovery. This grouping is still useful, despite the lack of chemical relatedness within each class, because it mirrors other underlying similarities. 

The course here outlined is essentially that offered by the writer at the University of Illinois in 1920. The basis for its claim to systematization is outlined in Chapters I and II. The most radical individual departure from other analytical schemes consists in the subdivision of organic compounds into seven solubility groups and the application of this classification to a systematic procedure. 

Examples of the Classification of Some Compounds into Solubility Groups and a Review of Compounds which are on the Boundaries of Solubility Classes ... 

Hormones can be classified according to chemical composition, solubility properties, location of receptors, and the namre of the signal used to mediate hormonal action within the cell. A classification based on the last two properties is illustrated in Table 42-3, and general feamres of each group are illustrated in Table 42-. ... 

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