Identification tests cotton

Visual and Manual Tests. Synthetic fibers are generally mixed with other fibers to achieve a balance of properties. Acryhc staple may be blended with wool, cotton, polyester, rayon, and other synthetic fibers. Therefore, as a preliminary step, the yam or fabric must be separated into its constituent fibers. This immediately estabUshes whether the fiber is a continuous filament or staple product. Staple length, brightness, and breaking strength wet and dry are all usehil tests that can be done in a cursory examination. A more critical identification can be made by a set of simple manual procedures based on burning, staining, solubiUty, density deterrnination, and microscopical examination. 

Identification of gases Many anions (e.g. carbonate, sulphide, sulphite, thiosulphate, and hypochlorite) are usually identified by the volatile decomposition products obtained with the appropriate reagents. Suitable apparatuses for this purpose are shown in Fig. 11.30. The simplest form (a) consists of a semimicro test-tube with the accompanying filter tube a strip of test paper (or of filter paper moistened with the necessary reagent) about 3-4 mm wide is suspended in the filter tube . In those cases where spray is likely to affect the test paper, a loose plug of cotton wool should be placed at the narrow end of the filter tube . Apparatus b is employed when the test reagent is a liquid. A... 

The cotton and rayon used as fillers in solid oral dosage form containers may not meet pharmacopeial standards, but through appropriate tests and acceptance criteria for identification and moisture content, their adequacy should be shown. For example, rayon has been found to be a potential source of dissolution problems for gelatin capsules and gelatin-coated tablets. 

AS 2836.2-1998. Methods of testing surgical dressing surgical dressing materials — Method for the identification of cotton viscose fibres. 

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