BS EN ISO 4098:2018 pdf free

BS EN ISO 4098:2018 pdf free.Leather – Chemical tests – Determination of water-soluble matter, water-soluble inorganic matter and water-soluble organic matter
Sample in accordance with ISO 2418 and grind leather in accordance with ISO 4044. If sampling in accordance with ISO 2418 is not possible (e.g. in the case of leathers from finished products, such as shoes or garments), details about sampling shall be given together with the test report.
Weigh accurately approximately 10 g of ground leather and record the mass (m0). Extract the leather in accordance with ISO 4048 before determination of the water- soluble matter.
If the result is to be presented on the basis of dry substance, then a further sample of the same leather shall be tested in accordance with ISO 4684, so that the moisture content can be calculated.
Quantitatively transfer the air-dried, ground, dichloromethane-extracted leather obtained from Clause 7 into a flask [6.1]. Add (500±10) ml of deionised water (5.2) at (23,5±3,5) °C, close the stopper securely and shake mechanically (6.5) at (50±10) cycles per minute for (120 min±10) min at (23,5±3,5) °C (see 9.1).
Filter the contents of the flask through a fluted filter paper (6.7) until the filtrate is clear. Discard the first 50 ml. Determine the water-soluble organic matter and inorganic matter in subsequent 50 ml aliquot portions of the filtrate (see 9.2 and 9.3).
Pipette 50,0 ml (6.3) of filtrate into a basin (6.4) which has previously been prepared by heating at 700 °C (6.10), cooled in a desiccator (6.11) and accurately weighed (6.12). Evaporate the filtrate over the water bath (6.8) and dry the residue at (102±2)°C (6.9) for approximately 2 h. Cool in a desiccator,using only one basin at a time in a small desiccator, and no more than two in a large desiccator. Weigh quickly, and repeat the drying, cooling and weighing procedure either until the further reduction in mass does not exceed 2 mg, or the total drying time equals 8 h. Record the final mass and calculate the mass of dry residue (m1).
Thoroughly wet the residue obtained in 8.2 (see 9.2) in the basin (6.4) with just sufficient 1 mol/l sulfuric acid (5.1), and heat gently over a low flame until no more sulfur trioxide fumes are visible. Heat more strongly until the basin approaches red heat. Transfer to the muffle furnace (6.10) at 700 °C for 15 min (see 9.4). Cool in the desiccator and weigh as quickly as possible. Repeat the addition of acid,heating, cooling and weighing until the further reduction in mass does not exceed 2 mg, or the total drying time equals 8 h. Record the final mass and calculate the mass of the sulfated residue, (m2).BS EN ISO 4098 pdf free.