Home>ASTM Standards>ASTM D6405-99(R2020) pdf free download

ASTM D6405-99(R2020) pdf free download

ASTM D6405-99(R2020) pdf free download.Standard Practice for Extraction of Tannins from Raw and Spent Materials
1. Scope
1.1 This practice covers extracting the tannin from raw and spent materials. The water extract obtained by this method is used to determine the tannin content of the original material. Analysis for total solids, soluble solids, and soluble non- tannins of the water extract from a material provides the information necessary to calculate the extractable tannin con- tent of that material. The types of materials typically analyzed by this practice are products of plants such as woods, barks, leaves, nuts, fruits, roots, etc. and any of a wide variety of by-products (spent materials) from industrial processes utiliz- ing plant products. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
7. Preparation of Sample
7.1 All of the sample, drawn as directed in Practice D6404, shall first be ground in a rough grinder, or shredded, to pass a sieve having round openings 1.27 cm (0.50 in.) in diameter. After this grinding, the sample shall be mixed and quartered, as described in the Quartering Samples section of Practice D6404 until about 450 g (1 lb) remains. This material shall then be ground to pass a sieve having circular openings of 2 mm diameter (U.S. Standard Sieve Series No. 10). This grinding shall be conducted in a Wiley mill or similar grinder. 7.2 Where the original sample is too wet to be ground, or where such grinding is likely to cause significant changes in the moisture content, samples of raw material shall be weighed, spread out on (canvas) trays which permit free circulation ofair all around the sample, and allowed to attain approximate moisture equilibrium with the laboratory atmosphere; the temperature at no time should exceed 60 °C. Spent materials should be similarly treated except that temperatures up to 100 °C may be used. The partially dried sample shall then be ground as described in 7.1. 7.2.1 In all cases, the loss of moisture during such drying must be determined and the results ofthe analysis calculated to the basis of the original moisture before drying. A second moisture shall be run on the finely ground sample. The method of determining these moisture values and calculating the original moisture content is found in Test Method D6403.
9. Procedure
9.1 Prepare duplicate extract samples. Extract raw materials to a volume of 2 L. Extract spent materials to a volume of 1 L. 9.2 Attach the extractor to a boiling-flask, which furnishes steam by the boiling of distilled water. Attach a reflux condenser to the top of the extractor and connect to a source of cold water. Close the outlet tube on the bottom stem of the apparatus just above the steam generating flask by attaching a section of tubing and a clamp which then can be used to help regulate the amount of steam passing into the extractor; this may be particularly helpful at the beginning of an extraction. Close the outlet tube of the extraction chamber by using a section of tubing (with a clamp) leading into the receiving vessel. Prepare a layer ofborosilicate glass wool, 0.64 cm (0.25 in.) thick, and place in the bottom of the extraction chamber, over the monel disc. Transfer the specimen to a tared container and weigh to the nearest 1 mg (0.001 g), taking every precaution to avoid changes in moisture content. Then wet the specimen with a minimum of distilled water, at 95 °C, and stir the mixture with a glass rod to ensure complete wetting. Then transfer the wetted specimen quantitatively, to the extractor, through a transfer funnel, using a minimum quantity of the hot distilled water. Remove entrapped air in the charge by stirring with a glass rod, taking care not to disturb the layer of glass wool.

Maybe you like

Standards Tags