ASTM D6401-99(R2020) pdf free download

ASTM D6401-99(R2020) pdf free download.Standard Test Method for Determining Non-Tannins and Tannin in Extracts of Vegetable Tanning Materials
3. Terminology
3.1 Definitions: 3.1.1 soluble non-tannins—non-volatile materials present in tannin extracts and raw or spent materials that are dissolved or suspended in water, are part ofthe soluble solids determined by Test Method D6402, and do not react with or bind to hide powder when mixed as in this test method. 3.1.2 tannins—non-volatile materials present in tannin ex- tracts and raw or spent materials that are dissolved or sus- pended in water, are part of the soluble solids determined by Test Method D6402, and do react with or bind to hide powder when mixed as in this test method.
4. Summary of Test Method
4.1 An aliquot of the analytical solution prepared from tannin extracts (Practices D4901 or D4905) or of the water extract from raw or spent materials (Practice D6405) is dried overnight in a forced-air oven (Test Method D4902) and the solid residue remaining is determined and defined as the total solids for that sample (Test Method D4903). Another aliquot of the same solution is passed through a specified filtering procedure and the quantity of solid residue remaining in the filtrate is determined and defined as the soluble solids for that sample; the calculated difference between the total solids and the soluble solids is defined as the insolubles for that sample (Test Method D6402). Another aliquot of the original analyti- cal solution or water extract is mixed with a prepared hide powder material, with the resulting solution being passed through the same filtering procedure as for the soluble solids analysis. The quantity of solid residue remaining in the filtrate is determined and defined as the soluble non-tannins for that sample; the calculated difference between the total soluble solids and the soluble non-tannins is defined as the tannin content for that sample.
5. Significance and Use
5.1 This test method is used to determine the proportion of the total soluble solids which are soluble non-tannins and the proportion which are tannins in a solution of tannin extract or in the water extract from raw or spent materials prepared for tannin analysis. 5.2 The specimens are aliquots from the analytical solutions prepared from tannin extracts or the water extract solutions prepared from raw or spent materials. 5.3 The soluble non-tannins are defined as the portion ofthe soluble solids which are not absorbed or bound by a prepared hide powder material. 5.4 The tannins are defined as the portion of the soluble solids which are absorbed or bound by a prepared hide powder material. 5.5 The results of this test method are dependent on a great many variables, but particularly upon: 5.5.1 The temperature conditions under which the solutions were prepared and stored and the temperature at which the current analysis is performed; 5.5.2 The uniformity and consistency of the Kaolin paste layer deposited onto the filter paper; 5.5.3 The rate of solution run-out from the pipette; 5.5.4 Conditions related to the properties ofthe hide powder used to react with the tannin content of the solution; etc. It is, therefore, essential that the method be followed exactly in order to obtain reproducible results both among specimens within a laboratory and for analyses between laboratories.
6. Apparatus and Reagents
6.1 Tannin Dish, crystallizing dish, borosilicate glass, 50 mm tall, 70 mm outside diameter. The bottom corner shall be rounded to a radius of 6 mm, the bottom shall be flat and not cupped in the center, and the top edge shall be rounded and polished. 6.2 Watch Glass, a suitable size (approximately 150 mm diameter) to be used as a cover for the funnel and filter paper and a suitable size (75 mm) to be used as a cover for the tannin dishes. 6.3 Pipet, 100 mL capacity, preferably with a wide orifice approximately 2.4 mm ( 3 ⁄ 32 in.) diameter and 15-25 s delivery time. 6.4 Volumetric Flasks, graduated to deliver 200 mL boro- silicate flask (Pyrex No. 5840 works well). 6.5 Filter Paper 4 , 21.5 cm diameter, pleated to contain 32 evenly divided creases. 6.6 Funnel, 100 to 125 mm top diameter, 60° angle bowl, and 150 mm stem length. 6.7 Shake Bottles, 0.95 L (32 oz), with rubber stoppers. The bottles shall be approximately 21.6 cm (8.5 in.) overall height and 8.9 cm (3.5 in.) diameter. One-quart canning jars (Mason- type) with plastic screw-on lids work well. 6.8 Shaking Machine, rotating type, equipped to hold 0.95 L (32 oz) bottles for end-over-end agitation of hide powder and analytical solution. The speed of rotation shall be 60 6 2 rpm, and the machine shall be so constructed that the side of the shake bottle adjacent to the rotating shaft shall be not less than 5.1 cm (2 in.) nor more than 7.6 cm (3 in.) from the center of the shaft.