BS EN ISO 4098:2018 pdf download

BS EN ISO 4098:2018 pdf download.Leather – Chemical tests – Determination of water-soluble matter, water-soluble inorganic matter and water-soluble organic matter.
6.12 Analytical balance weighing to an accuracy of 0.001 g.
7 Sampling and preparation of samples
Sample in accordance with ISO 2418 and grind leather in accordance with ISO 4044. If sampling in accordance with 15112418 is not possible (e.g. in the case of leathers from linished products, such as shoes or garments), details about sampling shall be gwen together with the test report.
Weigh accurately approximately lOg of ground leather and record the mass (mo). Extract the leather In accordance with 1SQ4048 before determination of the water-soluble matter.
lithe 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.
8 Procedure
8.1 General
Quantitatively transfer the air-dried, ground. dichioromethane-extracted leather obtained from
Clawie3 into a flask (6.1). Add (500 ± 10) ml of delonised water (5.2) at (23,5 ± 3,5) °C. close the topper securely and shake mechanically (6.5) at (50 ± 10) cycles per minute for (120 mm ± 10) mm at (23,5 ± 3,5) C (see 2.1).
Filter the contents of the flask through a fluted filter paper (62) until the liltrate is clear. Discard the first SO 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).
8,2 Water-soluble matter
Pipette 30.0 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 (.9) for approximately 2 ii. 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 (ml).
8.3 Water-soluble inorganic matter
Thoroughly wet the residue obtained in 112 (see 2.2) 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. I teat more strongly until the basin approaches red heat. Transfer to the muffle furnace (6.1.0) at 700 C for 15 mm (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, (mz).
9 Remarks on the procedure
9.1 If the specified extraction temperature of (23.5*3,5) C cannot be maintained in the test room, it is advisable to use a vacuum flask of 650 ml to 750 ml capacity. The range of values of the total water-soluble matter, WJw%, Isee Clause 10 a)l is likely to differ by about 0.5% over the permitted temperature range.
9.2 The water-soluble matter and the water-soluble inorganic matter can each be determined separately. Water-soluble matter can he determined by evaporating 50 ml portions of the filtrate in previously dried platinum, quartz, silver, porcelain or glass dishes at (102 ± 2) °C, in accordance with &Z. WatersolubIe Inorganic matter can be dctermlncd by the evaporation of separate 50 ml portions in previously heated quartz, platinum or glazed porcelain dishes in accordance with tL3.
9.3 If the mass of water-soluble inorganic matter is likely to be less than 2,0% of the leather mass, it is recommended that a 100 ml or 200 ml aliquot portion should be used. In cases where the result Is likely to be less than 1,0%, a 100 ml or 200 ml portion should always be used.
9.4 At temperatures above 700°C some loss olmass from the residue is possible, owing to volatilisation of certain inorganic salts. For this reason close control is essential to prevent the maximum furnace temperature from exceeding 700 °C.
10 Calculation and expression of results
Calculate the following percentages when the evaporated volume of water is 1/10 of the total volume. If other volumes are used then the factor 10 shall be changed appropriately.