《ISO-5399-1984.pdf》由会员分享，可在线阅读，更多相关《ISO-5399-1984.pdf（8页珍藏版）》请在三一文库上搜索。
1、z - 8 m v- I i% l2 0 v, International Standard INTERNATIONAL ORGANIZATION FOR STANDARDZATONOMEIKYHAPOHA OPI-AHM3ALWlR I-IO CTAHAPTM3AiJMM*ORGANlSATlON INTERNATIONALE DE NORMALISATION Leather - Determination of water-soluble magnesium salts - EDTA titrimetric method Cuir - Determination de la teneur
2、en sels de magnksium solubles dans l eau - IWthode titrimktrigue ;j I ED TA First edition - 1984-03-01 UDC 675 : 543.831 Ref. No. IS0 5399-1984 (E) Descriptors : leather, tanning, tests, determination of content, magnesium sulfates, volumetric analysis. Price based on 3 pages Copyright International
3、 Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- Foreword IS0 (the international Organization for Standardization) is a
4、 worldwide federation of national standards bodies (IS0 member bodies). The work of developing International Standards is carried out through IS0 technical committees. Every member body interested in a subject for which a technical committee has been authorized has the right to be represented on tha
5、t committee. lnternational organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the I
6、S0 Council. lnternati onal Standard IS0 5399 was developed by Technical Co Leather, and was circulated to the member bodies in May 1981 mmittee ISO/TC 120, It has been approved by the member bodies of the following countries : Brazil India China Italy Czechoslovakia Kenya Egypt, Arab Rep. of Korea,
7、Rep. of Ethiopia Mexico Germany, F. R. New Zealand Hungary Romania South Africa, Rep. of Spain Sri Lanka Tanzania Turkey United Kingdom USSR The member body of the following country expressed disapproval of the document : France This International Standard is based on method IUC/9 of the Internation
8、al Union of Leather Technologists and Chemists Societies. 0 International Organization for Standardization, 1984 Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26
9、/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 5399-1984 (E) Leather - Determination of water-soluble magnesium salts - EDTA titrimetric method 1 Scope and field of application This International Standard specifies an EDTA titrimet
10、ric method for the determination of water-soluble magnesium salts in leather. It is applicable to all leather which contains magnesium salts. 5 Reagents During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 5.1 Ammonium chloride
11、, solid. 5.2 Sodium chloride, solid. 2 References IS0 385, Laboratory glassware - Burettes. IS0 4098, Leather - Determination of total water-soluble matter, water-soluble inorganic matter and water-soluble organic matter. 1) I SO 4788, Laboratory glassware - Graduated measuring cylinders. 3 Definiti
12、on For the purposes of this International Standard, the following definition applies. magnesium salts content of leather : The quantity of magnesium salts, calculated as magnesium sulfate (MgS0,.7H,O), obtained by extraction with water under the specified conditions. 5.3 Ammonium hydroxide, 25 % (V/
13、V) solution of ammonia, e = 0,880 g/ml. 5.4 Ammonium hydroxide, 2 mol/l solution. 5.5 Sodium hydroxide, 2 mol/l solution. 5.6 Hydrochloric acid, 2 mol/l solution. 5.7 Ammonia/ammonium chloride buffer solution, of pH IO,5 (see 9.1). 5.8 Disodium ethylenedinitrilotetraacetate dihydrate INa,EDTA), 0,Ol
14、 mol/l standard volumetric solution (see 9.2). 5.9 Methyl orange, 2 g/l solution. 5.10 Suitable indicator, for example Eriochrome black T (see 9.3). 4 Principle Aqueous extraction of a test portion, followed by evaporation and drying at 102 + 2 OC, and sulfating and ashing of the residue at 800 OC,
15、to yield the water-soluble inorganic matter. Treatment of the residue with hydrochloric acid, and titration with standard volumetric disodium ethylenedinitrilotetraacetate solution. (See also 9.4.) 6 Apparatus Ordinary laboratory apparatus and 6.1 Burette, with appropriate scale, complying with the
16、requirements of IS0 385. 1) At present at the stage of draft. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license
17、from IHS -,-,- IS0 5399-1984 (E) 6.2 Conical flask, of capacity 300 ml. 6.3 Measuring cylinders, of capacity 50 and 250 ml, com- plying with the requirements of IS0 4788. 6.4 Thermometer. 7 Procedure Treat the residue in the crucible after the determination of the water-soluble ash in accordance wit
18、h IS0 4098, with a little of the hydrochloric acid solution (5.6) dissolved by gentle warm- ing (see 9.4.1). Transfer the solution into the conical flask (6.2). Rinse the crucible several times with a very little of the hydrochloric acid solution and water; neutralize the solution against the methyl
19、 orange solution (5.9) with either the ammonia (5.4) or the sodium hydroxide solution (5.5) and boil briefly. Dilute the solution in the flask with 150 ml of water, add 20 ml of the buffer solution (5.71, adjust to 50 OC by cooling or heating, and add the indicator (5.10) until the solution becomes
20、a clear red. Titrate with the Na*EDTA solution (5.8) until the colour changes to pure blue (with no red tint). 0,002 465 is the mass, in grams, of MgS0,.7H,O corresponding to 1,00 ml of exactly 0,Ol mol/l Na2EDTA solution. Take as the result the mean of two determinations, provided that the requirem
21、ent for repeatability (see 8.2) is satisfied, and express it to one decimal place. 8.2 Repeatability The results of duplicate determinations carried out by the same operator in the same laboratory shall not differ by more than 0,03 % bh.n) MgO or 0,2 % (m/m) MgS0,.7H,O. 9 Notes on procedure 9.1 Prep
22、aration of ammonia/ammonium chloride buffer solution (5.7) Add 54 g of the ammonium chloride (5.1) to 350 ml of the ammonium hydroxide solution (5.3) and make up with water to 1 litre. 9.2 Preparation and standardization of the Na,EDTA solution (5.8) 8 Expression of results 9.2.1 Preparation 8.1 Cal
23、culation 8.1.1 The magnesium salts content, expressed tage by mass as MgO, is given by the formula V - x 0,000 403 x 10 x 100 m V = 0,403 x - m as a percen- where V is the volume, in millilitres, of the standard volumetric Na*EDTA solution (5.8) used for the titration; m is the mass, in grams, of th
24、e test portion (see IS0 4098); . 0,000 403 is the mass, in grams, of MgO corresponding to 1,00 ml of exactly 0,Ol mol/l Na*EDTA solution. 8.1.2 The magnesium salts content, expressed as a percen- tage by mass as MgS0,7H,O, is given by the formula V - x 0,002 465 x 10 x 100 m V = 2,465 x - m Dry the
25、Na*EDTA at 80 OC for several hours. Weigh accurately 3,722 g of the dried Na2EDTA , dissolve in water in a 1 000 ml one-mark volumetric flask, make up to the mark and mix well. The solution can be kept for a practically unlimited time in closed Pyrex glass or polythene vessels, but should be restand
26、ardized before use. 9.2.2 Standardization Weigh accurately approximately 0,16 g of chemically pure zinc powder, mix with 100 ml of the hydrochloric acid solution (5.6) and heat on a water-bath until completely dissolved. Transfer the solution to the 250 ml measuring cylinder (6.31, cool and make up
27、to the highest graduation line. Pipette 25 ml of this solution into a conical flask, dilute with 50 ml of water and add 30 ml of the ammonium hydroxide solution (5.4). Add the in- dicator (5.10) (see 9.3) until clear red. Titrate with the Na*EDTA solution (9.2.1) until the colour is converted to pur
28、e blue (without red tint). 9.2.3 Calculation of concentration The concentration c of the standard volumetric Na2EDTA solu- tion, expressed in moles per litre, is given by the formula ml 10 c = - 0,653 8 K where V and m are as defined in 8.1 .l; 2 9 is the mass, in milligrams, of zinc used for the st
29、an- dardization (9.2.2); Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- ISQ 5399-1984 (E) VI i
30、s the volume, in millilitres, of the Na*EDTA solution (9.2.1), used for the titration; 0,653 8 is the mass, in milligrams, of zinc corresponding to I,00 ml of exactly 0,Ol mol/l Na*EDTA solution. 9.3 Dilution of the Eriochrome black T indicator Mix well together 1 part of Eriochrome black T with 300
31、 parts of the solid sodium chloride (5.2). Add the indicator in its solid state to the solution. In this way, the diluted indicator will keep for an unlimited period. 9.4 Preliminary treatment of the test portion If the sulphated ash of water-solubles obtained in accordance with SLC/5, 1966.5.4, is
32、used for the determination, it is necessary first to eliminate any interfering phosphate and/or calcium ions, if qualitative tests have shown their presence. This can be done in accordance with 9.4.1 and 9.4.2. 9.4.1 Elimination of phosphate ions Mix the ash in the crucible with 5 ml of 10 % (m/m) h
33、ydrochloric acid solution and dissolve under slight heat. Rinse the solution in a 250 ml glass beaker and dilute with water to approximately 50 ml. Then add 3 ml of 10 % (m/m) ammonium chloride solution, a few drops of concentrated nitric acid and a few drops of 10 % (m/m) iron(lll) chloride solutio
34、n. Make the solution alkaline with ammonia, and boil. The precipitate that forms should be quite brown in colour. If it is not, then acidify again with hydrochloric acid, add a few drops of iron(lll) chloride solution and make alkaline with ammonia. Repeat this procedure until the formation of a dis
35、tinctly brown- coloured precipitate occurs. Filter the solution while warm water. and wash out the beaker with hot 9.4.2 Elimination of calcium ions Dissolve the ash in the crucible in accordance with 9.4.1 or use the filtrate after elimination of the phosphate ions in accor- dance with 9.4.1. Treat
36、 the solution of the ash or filtrate with 3 ml of 10 % (m/m) ammonium chloride solution, 7,5 ml of 10 % (m/m) ammonium hydroxide solution and 0,5 ml of 5 % (m/m) ammonium oxalate solution. Heat the solution to boiling, transfe r to a 100 ml measuring flask and adjust to vol ume; mix and fil ter thro
37、ugh a fluted filter. Pipette 50 ml of the filtrate into a 400 ml glass beaker, dilute with 100 ml of water, and determine the magnesium content in accordance with clause 7. 10 Test report The test report shall contain the following particulars : a) reference to this International Standard; b) the us
38、ed; results obtained and the method of expression c) any unusual features noted during the determination; d) any operation not included in this International Stan- dard or the International Standards to which reference is made, or regarded as optional. Copyright International Organization for Standa
39、rdization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- This page intentionally left blank Copyright International Organization for Standardization Pr
40、ovided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- This page intentionally left blank Copyright International Organization for Standardization Provided by IH
41、S under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- This page intentionally left blank Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,-