1、BRITISH STANDARD BS 551:1990 Specification for Butyl acetate for industrial useBS551:1990 This British Standard, having been prepared under the directionof the Chemicals Standards Policy Committee, waspublished under the authorityof the Board of BSIandcomes into effect on 31August1990 BSI 11-1999 Fi
2、rst published May 1934 Second edition March 1950 Third edition December 1956 Fourth edition June 1965 Fifth edition August 1990 The following BSI references relate to the work on this standard: Committee reference CIC/51 Draft for comment 89/50508 DC ISBN 0 580 18571 0 Committees responsible for thi
3、s British Standard The preparation of this British Standard was entrusted by the Chemicals Standards Policy Committee (CIC/-) to Technical Committee CIC/51, upon which the following bodies were represented: British Pharmacopoeia Commission British Society of Perfumers Chemicals Industries Associatio
4、n Royal Society of Chemistry Solvents Industry Association Ltd. Amendments issued since publication Amd. No. Date CommentsBS551:1990 BSI 11-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Description 1 3 Sampling and size of sample 1 4 Colour 1 5 Density 1 6 Di
5、stillation range 1 7 Residue on evaporation 1 8 Water content 1 9 Acidity 1 10 Ester content 1 Appendix A Determination of distillation range 2 Appendix B Determination of acidity 2 Appendix C Determination of ester content 3 Publication(s) referred to Inside back coverBS551:1990 ii BSI 11-1999 Fore
6、word This British Standard, which has been prepared under the direction of the Chemicals Standards Policy Committee, supersedes BS551:1965which is withdrawn. In this revision of BS551the requirement for residue on evaporation has been made more stringent and the requirement for relative density has
7、been replaced by one for density at20 C. In addition, some of the appendices describing test methods in the previous edition have been replaced by references to general test methods. This British Standard is related to ISO1386:1983but is not equivalent in technical content. ISO1386is published by th
8、e International Organization for Standardization (ISO). ISO1386lists various general test methods, which correspond to those to which reference is made in this British Standard, and it also describes methods for the determination of acidity and for the determination of ester content which are simila
9、r to those described in Appendix B and Appendix C, respectively, of this British Standard. ISO1386does not specify limits for any of the properties of butyl acetate or other solvent acetates. A British Standard does not purport to include all the necessary provisions of a contract. Users of British
10、Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 4, an inside back cover and a back cover. Th
11、is standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS551:1990 BSI 11-1999 1 1 Scope This British Standard specifies requirements for butyl acetate suitable for industrial purposes. NOTETh
12、e titles of the publications referred to in this standard are listed on the inside back cover. 2 Description The material shall be clear and free from matter in suspension, as assessed by visual inspection, and shall consist essentially of the acetic ester of butan-1-ol (CH 3 COOCH 2 CH 2 CH 2 CH 3
13、). 3 Sampling and size of sample 1) A representative sample of the material measuring not less than0.5L shall be taken from the bulk for the purpose of examination in accordance with this standard. The sample shall be placed in a clean, dry and air-tight, ground glass-stoppered bottle, or screw-capp
14、ed bottle fitted with a polyethylene cone insert, of such capacity that it is almost filled by the sample. NOTE 1When it is necessary to seal the container, care should be taken to avoid the risk of contaminating the contents in any way. NOTE 2Sufficient ullage should be left in the bottle to avoid
15、excessive pressure changes that could arise from temperature variations during storage and handling. About10% ullage is recommended. 4 Colour The colour of the material shall not exceed15Hazen colour units when measured by the method described in BS 5339. 5 Density The density of the material at20 C
16、, measured by the method described in BS 4522, shall be not lower than0.878g/mL and not higher than0.881g/mL. 6 Distillation range When the material is distilled by the method described in BS 4591, modified as described in Appendix A, the initial boiling point at101.3kPa pressure shall be not lower
17、than124.0 C and the dry point at101.3kPa pressure shall be not higher than129.0 C. 7 Residue on evaporation The residue on evaporation of the material shall not exceed0.0020% (m/m) when determined by the method described in BS 4524. 8 Water content The material shall not contain more than0.10%(m/m)
18、of water when determined by the method described in clause 2 of BS 2511:1970 using20mL of the material. 9 Acidity The acidity of the material, calculated as acetic acid (CH 3 COOH), shall not exceed0.010% (m/m) when determined by the method described in Appendix B. 10 Ester content The material shal
19、l contain not less than97.0% (m/m) of esters, calculated as butylacetate (CH 3 COOC 4 H 9 ), when determined bythe method described in Appendix C. 1) Detailed information on the sampling of liquid chemical products is given in BS 5309-1 and 5309-3.BS551:1990 2 BSI 11-1999 Appendix A Determination of
20、 distillation range Determine the distillation range, in terms of the initial boiling point and the dry point, by the method described in BS 4591, using the following thermometer and temperature corrections. a) Thermometer (5.1.2 of BS 4591:1990). Use a thermometer designated F150C/100 complying wit
21、h BS 593. b) Corrections to be applied to observed temperatures (9.1.2 of BS 4591:1990). If the corrected barometric pressure deviates from101.3kPa apply corrections to the observed temperatures by substracting0.037 C for every0.1kPa above101.3kPa, or adding0.037 C for every0.1kPa below101.3kPa. NOT
22、EThese corrections are valid only for pressures above93.3kPa. Appendix B Determination of acidity B.1 Principle A test portion is diluted with95% (V/V) ethanol (ormethylated spirits) and titrated with standard volumetric sodium hydroxide solution, using phenolphthalein as indicator. B.2 Reagents B.2
23、.1 General During the analysis, use only reagents of recognized analytical grade, only methylated spirits complying with BS 3591, and only water complying with grade3of BS 3978. B.2.2 Ethanol or industrial methylated spirits,95%(V/V). NOTEThe use of industrial methylated spirits is governed by The M
24、ethylated Spirits Regulations, 1983 (S.I. 1983 No. 252). It is not permissible to use duty-free ethanol, received under the provisions of The Alcoholic Liquor Duties Act 1979, Section 10, for purposes for which industrial methylated spirits is an acceptable alternative. B.2.3 Sodium hydroxide, stand
25、ard volumetric solution, c(NaOH) =0.100mol/L. B.2.4 Phenolphthalein, 5g/L ethanolic solution. Dissolve0.5g of phenolphthalein in100mL of the ethanol or industrial methylated spirits (B.2.2) and add the sodium hydroxide solution (B.2.3) until a pale pink coloration is obtained. B.3 Apparatus B.3.1 Or
26、dinary laboratory apparatus B.3.2 Conical flask, of250mL capacity, of borosilicate glass, fitted with a ground glass stopper carrying a guard tube containing sodium hydroxide on an inert support (soda lime). B.3.3 Burette, of10mL capacity, graduated in0.02mL divisions, complying with class A of BS84
27、6. B.4 Procedure B.4.1 Test portion Take50 0.5mL of the sample, measured at20 C. B.4.2 Determination Place50mL of the ethanol or industrial methylated spirits (B.2.2) in the conical flask (B.3.2), add0.5mL of the phenolphthalein solution (B.2.4) and add the sodium hydroxide solution (B.2.3) until a
28、pale pink coloration is obtained. Add the test portion (B.4.1), mix and titrate the mixture with the sodium hydroxide solution, using the burette(B.3.3), until a pink coloration, persisting for at least10s, is obtained. Stopper the flask and swirl its contents after each addition of sodium hydroxide
29、 solution. B.5 Expression of results The acidity A, expressed as a percentage by mass of acetic acid (CH 3 COOH), is given by the equation: i.e. where Report the result to two significant figures. B.6 Test report The test report shall include the following information: a) a complete identification o
30、f the sample; b) a reference to the method used, i.e. BS 551, Appendix B; c) the results expressed in accordance with B.5; d) any unusual features noted during the determination; e) any operation not included in this appendix or regarded as optional. V 1 is the volume of the sodium hydroxide solutio
31、n used for the determination (inmL); is the density of the sample at20 C (determined by the method described in BS4522) (in g/mL); 0.006 is the mass of acetic acid corresponding to1.00mL of sodium hydroxide solution, c(NaOH) =0.100mol/L (in g).BS551:1990 BSI 11-1999 3 Appendix C Determination of est
32、er content C.1 Principle The esters present in a test portion are saponified with excess ethanolic potassium hydroxide solution and the excess is determined by titration with standard volumetric hydrochloric acid solution, using phenolphthalein as indicator. C.2 Reagents C.2.1 General During the ana
33、lysis, use only reagents of recognized analytical grade, only methylated spirits complying with BS 3591, and only water complying with grade3of BS 3978. C.2.2 Potassium hydroxide,56g/L solution in95%(V/V) ethanol or95% (V/V) industrial methylated spirits. NOTEThe use of industrial methylated spirits
34、 is governed by The Methylated Spirits Regulations, 1983 (S.I. 1983 No. 252). It is not permissible to use duty-free ethanol, received under the provisions of The Alcoholic Liquor Duties Act 1979, Section 10, for purposes for which industrial methylated spirits is an acceptable alternative. C.2.3 Hy
35、drochloric acid, standard volumetric solution, c(HCl) =1mol/L. C.2.4 Phenolphthalein,5g/L ethanolic solution. Prepare as described in B.2.4. C.3 Apparatus C.3.1 Ordinary laboratory apparatus C.3.2 Two conical flasks, of borosilicate glass, capacity250mL, fitted with ground glass stoppers. C.3.3 Two
36、reflux condensers, water-cooled, with ground glass joints to fit conical flasks (C.3.2). C.3.4 Weighing pipette, capacity10mL. C.4 Procedure C.4.1 Test portion Using the weighing pipette (C.3.4), transfer between2.7g and3.2g of the sample, weighed to the nearest0.001g, to a conical flask (C.3.2) con
37、taining50.0mL of the potassium hydroxide solution (C.2.2), introduced by means of a one-mark pipette. C.4.2 Blank test Introduce50.0mL of the potassium hydroxide solution (C.2.2), using the same one-mark pipette referred to in C.4.1, into the second conical flask(C.3.2). C.4.3 Determination Attach a
38、 reflux condenser to each conical flask and heat the two flasks for1h in a boiling-water bath. Withdraw the flasks, still carrying their condensers, and immerse them in cold running water. When cool, wash down the inside of each condenser with two20mL portions of water, collecting the washings in th
39、e flask. Disconnect the flasks and wash each joint with a further20mL of water, again collecting the washings in the appropriate flask. Add0.5mL of the phenolphthalein solution (C.2.4) to each flask and immediately titrate the contents of each flask in turn with the hydrochloric acid solution (C.2.3
40、) until the pink colour is just discharged. C.5 Expression of results The ester content E, expressed as a percentage by mass of butyl acetate (CH 3 COOC 4 H 9 ), is given by the equation: where Report the result to one decimal place. C.6 Test report The test report should include the following infor
41、mation: a) a complete identification of the sample; b) a reference to the method used, i.e. BS 551, Appendix C; c) the results expressed in accordance with C.5; d) any unusual features noted during the determination; e) any operation not included in this appendix or regarded as optional. V 0 is the
42、volume of the hydrochloric acid solution used for the titration of the blank (in mL); V 1 is the volume of the hydrochloric acid solution used for the titration of the test solution (in mL); m is the mass of the test portion (in g); 116.2 is the relative molecular mass of butyl acetate.4 blankBS551:
43、1990 BSI 11-1999 Publication(s) referred to BS 593, Specification for laboratory thermometers. BS 846, Specification for burettes. BS 2511, Methods for the determination of water (Karl Fischer method). BS 3591, Specification for industrial methylated spirits. BS 3978, Specification for water for lab
44、oratory use. BS 4522, Method for determination of absolute density at20 C of liquid chemical products for industrial use. BS 4524, Method for determination of residue on evaporation on a water bath. BS 4591, Method for determination of distillation characteristics of organic liquids (other than petr
45、oleum products). BS 5309, Methods for sampling chemical products. BS 5309-1, Introduction and general principles. BS 5309-3, Sampling of liquids. BS 5339, Method of measurement of colour in Hazen units (platinum-cobalt scale) of liquid chemical products. ISO 1386, Solvent acetates for industrial use
46、 Methods of test 2) . 2) Referred to in the foreword only.BS 551:1990 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level
47、. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grate
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