1、April 2009DEUTSCHE NORM Normenausschuss Materialprfung (NMP) im DINDIN-SprachendienstEnglish price group 7No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale
2、 for German Standards (DIN-Normen).ICS 75.080!$.x“1931185www.din.deDDIN 51559-1Testing of mineral oils Determination of the saponification number Part 1: Saponification numbers above 2, colour-indicator titrationEnglish translation of DIN 51559-1:2009-04Prfung von Minerallen Bestimmung der Verseifun
3、gszahl Teil 1: Verseifungszahlen ber 2, Farbindikator-TitrationEnglische bersetzung von DIN 51559-1:2009-04Essais des huiles minrales Dtermination de lindice de saponification Partie 1: Indices de saponification suprieurs 2; titrage lindicateur colorTraduction anglaise de DIN 51559-1:2009-04Supersed
4、esDIN 51559-1:1978-04www.beuth.deDocument comprises 9 pages05.13 DIN 51559-1:2009-04 2 A comma is used as the decimal marker. Contents Page Foreword 3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Principle 4 5 Designation 4 6 Apparatus .5 7 Reagents .5 8 Sampling .6 9 Procedure .6
5、 9.1 Sample size 6 9.2 Determination of saponification number 6 9.3 Blank determination 6 10 Evaluation .7 11 Expression of result 7 12 Precision .7 12.1 General 7 12.2 Repeatability .7 12.3 Reproducibility .7 Bibliography 9 DIN 51559-1:2009-04 3 Foreword This standard has been prepared by Working G
6、roup NA 062-06-61 AA Prfung von Schmierlen, sonstigen len und Paraffinen of the Fachausschuss Minerall- und Brennstoffnormung (Standardization of petroleum, fuels, lubricants and related products committee (FAM) of the Normenausschusses Materialprfung (Materials Testing Standards Committee). This st
7、andard has been prepared on the basis of ASTM D 94:2007 Test Methods for Saponification Number of Petroleum Products1), issued by the American Society for Testing and Materials (ASTM), West Conshohocken, Pa, USA and adopted as American Standard ANSI/ASTM D 94:2007 and IP 136 Section 1/98 Methods of
8、test for petroleum and its products. Determination of saponification number. Colour-indicator titration method. Section 136.1: Colour-indicator titration method 1)adopted and issued as British Standard BS 2000-136.1:1998 by the British Standards Institution, London, Great Britain. However, this stan
9、dard differs as follows: a) instead of methyl ethyl ketone and naphtha the same solvent mixture (toluene, isopropanol alcohol and water) as used for the determination of the neutralization number in accordance with DIN 51558-1 and in order to prevent 2-phase titration has been used; b) the initial s
10、ample mass has been changed so that 40 % to 80 % of the potassium hydroxide solution used is consumed; c) unlike the ASTM/IP-Standard, the Baader flask may also be used for titration. DIN 51559 Testing of mineral oils Determination of the saponification number consists of the following parts: Part 1
11、: Saponification numbers above 2, colour-indicator titration Part 2: Colour-indicator titration, insulating oils Amendments This standard differs from DIN 51559-1:1978-04 as follows: a) Subclause 8.3 “Blank determination” has been included; b) the normative references have been updated; c) the stand
12、ard has been editorially revised. Previous editions DIN DVM 3659 = DIN 53659: 1932-11, 1936-02 DIN 51559: 1955-06 DIN 51559-1: 1978-04 1)Obtainable from: Beuth Verlag GmbH, AuslandsNormen-Service (ANS), 10772 Berlin.DIN 51559-1:2009-04 4 1 Scope This standard specifies a method of determining the sa
13、ponification number of the mineral oils specified in Clause 1. The saponification number serves to determine the content of saponifiable constituents of mineral oils. The method specified allows relative changes to be detected which occur in a mineral oil during operation due to a change in the sapo
14、nification number. This standard applies to new and used mineral oils, including those containing additives (e.g. of animal and plant origin), which are saponifiable under the conditions specified in this standard. It should be noted that alkali or acid consuming compounds of sulfur, phosphorus, hal
15、ogens or other elements are likely to affect the result. This aspect shall be taken into account when interpreting results obtained from such products. In such case the saponification number is suitable only for identifying the change in the oil. NOTE The substances referred to above, which are not
16、considered saponifiable, include inorganic or organic acids, and most nonalkali soaps. The presence of such substances increases the saponification number above that of fatty saponifiable matter. The odour of hydrogen sulfide near the end of the back titration is an indication that certain reactive
17、sulfur compounds are present in the sample. Other reactive sulfur, chlorine, and phosphor compounds give no simple indication during the determination of the actual fatty acid content. A gravimetric determination of the actual fatty acid content is probably the most reliable method for determining s
18、uch compounds. ASTM D 128:1998 can be used to determine fatty acids gravimetrically. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of t
19、he referenced document (including any amendments) applies. DIN 51750-1, Sampling of petroleum products General information DIN 51750-2, Sampling of liquid petroleum products DIN EN ISO 4259, Petroleum products Determination and application of precision data in relation to methods of test 3 Terms and
20、 definitions For the purposes of this document, the following term and definition applies. 3.1 saponification number VZ quantity of alkali, expressed in milligrams of potassium hydroxide (KOH) consumed by 1 g of a sample under the conditions specified in this standard 4 Principle A known mass of the
21、 oil sample is dissolved in a mixture of toluene and 2-propanol (isopropyl alcohol) and is heated with a known amount of alcoholic KOH solution. The excess KOH is titrated with hydrochloric acid, using phenolphthalein as indicator. The saponification number is calculated from the amount of KOH consu
22、med. 5 Designation Designation of the method of determining the saponification number by colour-indicator titration of mineral oils (M) in accordance with this standard (01): Test DIN 51559-01-M DIN 51559-1:2009-04 5 6 Apparatus 6.1 Conical flask, e.g. flask as specified in DIN ISO 1773, flask as sp
23、ecified in DIN EN ISO 4797 or Baader flask, made of glass of hydrolytic resistance class as specified in DIN ISO 719. 6.2 Mushroom-type condenser or immersion condenser or Allihn condenser, e.g. condenser K250-29 as specified in DIN 12581. NOTE The glassware should be cleaned. It is recommended that
24、 flasks be cleaned with chromic acid and rinsed with distilled water. Scratched or etched flasks should not be used. Since new flasks sometimes yield higher values, blank values should be determined for the old and new flasks and then compared. 6.3 Schellbach burette of 25-ml capacity, e.g. as speci
25、fied in DIN EN ISO 385. 6.4 Hot plate, electric. 7 Reagents 7.1 General Unless otherwise specified, only analytical grade reagents and distilled water or water of equivalent purity shall be used. 7.2 Alcohol a) 2-Propanol (isopropyl alcohol), 99 % (mass fraction); b) ethanol (ethyl alcohol), 95 % (m
26、ass fraction) or c) ethanol (ethyl alcohol), 95 % (mass fraction) with 10 % methanol (volume fraction). Ethanol (ethyl alcohol) shall be used for referee tests. Cleaning shall be carried out as follows: Dissolve 1,5 g of silver nitrate, AgNO3, in 3 ml of water, add to 1 l of ethanol and shake vigoro
27、usly. Dissolve 3 g of KOH in 10 ml to 15 ml of hot ethanol and, after cooling, add to the alcoholic AgNO3 solution while stirring gently. Allow the silver oxide, Ag2O, to settle down, decant the clear solution and distil over a water bath. 7.3 Alcoholic potassium hydroxide solution (0,5 M or 0,1 M)
28、Dissolve 28 g or 5,6 g of KOH in 1 l of ethanol or 2-propanol (isopropyl alcohol) (7.2). After settling in a dark place, decant or filter the clear solution. Standardize not before 24 h. 7.4 Aqueous hydrochloric acid (0,5 M or 0,1 M) In case of saponification numbers below 10, better precision can b
29、e obtained by using 0,1 M KOH and 0,1 M HCl. 7.5 Phenolphthalein solution Dissolve 1 g of phenolphthalein in 100 ml ethanol (7.2). Neutralize to a faint pink colour with 0,1 M alcoholic KOH solution. 7.6 Titration solvent Add 500 ml of toluene and 5 ml of water to 495 ml of anhydrous 2-propanol (iso
30、-Propyl alcohol). DIN 51559-1:2009-04 6 8 Sampling In accordance with DIN 51750-1 and DIN 51750-2. 9 Procedure 9.1 Sample size Choose the size of the sample so that 40 % to 80 % of the potassium hydroxide solution is consumed, but take care not to exceed a sample size of 20 g. Depending on the expec
31、ted saponification number, the sample sizes specified in Table 1 are recommended: Table 1 Saponification number Sample size Molarity of hydrochloric acid or potassium hydroxide solution VZ mg KOH/g g M Below 5 20 0,1 Above 5 up to 10 10 0,1 Above 10 up to 30 20 0,5 Above 30 up to 50 10 0,5 Above 50
32、up to 110 5 0,5 Above 110 up to 180 3 0,5 Above 180 up to 280 2 0,5 Above 280 1 0,5 9.2 Determination of saponification number Weigh the sample to the nearest 0,01 g into the conical flask. Add (25 1) ml of titration solvent. Following the dissolution of the sample, add (25 0,03) ml of alcoholic pot
33、assium hydroxide solution. Connect the condenser to the flask and bring the solution to a boil and keep boiling for 30 min under reflux conditions. Disconnect the condenser and cautiously add 50 ml of titrant. Add 3 drops of indicator solution and titrate the solution while hot, without reboiling, w
34、ith hydrochloric acid. When the colour is discharged, add 3 drops of indicator solution. If this addition of indicator restores the colour, continue the titration, making further dropwise additions of indicator, if necessary, until the end point is reached. The end point is reached when the colour i
35、s discharged and does not immediately reappear upon the addition of further 3 drops of indicator solution. 9.3 Blank determination It is necessary to perform a blank determination with each set of samples. Measure (25 1) ml of titration solvent into a conical flask and add (25 0,03) ml of alcoholic
36、potassium hydroxide solution. Continue as specified in 9.2. For referee tests, carry out blank determinations in duplicate. DIN 51559-1:2009-04 7 10 Evaluation Calculate the saponification number VZ using the following equation: EVVMVZ)(1,5621= where VZ is the saponification number, in mg KOH/g; M i
37、s the molarity of hydrochloric acid; V1is the volume of hydrochloric acid used in accordance with 9.3 (blanc determination), in ml; V2is the volume of hydrochloric acid used in accordance with 9.2 (sample determination), in ml; E is the initial sample mass, in g. 11 Expression of result Report the r
38、esult as saponification number VZ, in mg KOH/g, with a reference to this standard. The number of places in which the result is expressed shall agree with the number of places specified in Clause 12 for the corresponding repeatability and reproducibility. 12 Precision 12.1 General As specified in DIN
39、 EN ISO 4259. No precision can be given for highly coloured new or used oils, or for oils which produce dark coloured solutions upon saponification, as colour may interfere with the detection of the end point of the titration. To assess the reliability of results, the parameters given in 12.2 and 12
40、.3 shall be used: 12.2 Repeatability The difference between two results, obtained by the same operator with the same apparatus under constant operating conditions on identical test material would not in the long run, in the normal and correct operation of the test method, exceed the value given by t
41、he curve in Figure 1. 12.3 Reproducibility The difference between two single and independent results, obtained by different operators working in different laboratories on identical test material would not in the long run, in the normal and correct operation of the test method, exceed the value shown
42、 by the curve in Figure 1. DIN 51559-1:2009-04 8 Key X Saponification number Y Precision 1 Repeatability 2 Reproducibility Figure 1 Repeatability, reproducibility DIN 51559-1:2009-04 9 Bibliography DIN 12581, Laboratory glassware Allihn condensers with standard ground joints DIN 51558-1, Testing of
43、mineral oils Part 1: Determination of the neutralization number Colour-indicator titration DIN EN ISO 385, Laboratory glassware Burettes DIN EN ISO 4797, Laboratory glassware Boiling flasks with conical ground joints DIN ISO 719, Glass Hydrolytic resistance of glass grains at 98 C Method of test and
44、 classification DIN ISO 1773, Laboratory glassware Narrow-necked boiling flasks ASTM D 94-072), Test Methods for Saponification Number of Petroleum Products ASTM D 128-982), Standard Test Methods for Analysis of Lubricating Grease/Note: 1. editorial change IP 136 Section 1/982), Methods of test for petroleum and its products. Determination of saponification number. Colour-indicator titration method. Section 136.1: Colour-indicator titration method 2)Obtainable from: Beuth Verlag GmbH, AuslandsNormen-Service (ANS), 10772 Berlin, Germany.
