1、BRITISH STANDARD BS 553:1990 Specification for Ethyl acetate for industrial useBS553:1990 This British Standard, having been prepared under the directionof the Chemicals Standards Policy Committee, waspublished under the authorityofthe Board of BSI andcomes intoeffect on 31 August1990 BSI 10-1999 Fi
2、rst published May1934 Second edition March1950 Third edition December1956 Fourth edition June1965 Fifth edition August1990 The following BSI references relate to the work on this standard: Committee reference CIC/51 Draft for comment89/50509 DC ISBN 0 580 18567 2 Committees responsible for this Brit
3、ish 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 Chemical Industries Association Solve
4、nts Industry Association Ltd. Amendments issued since publication Amd. No. Date CommentsBS553:1990 BSI 10-1999 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 Distillation range 1 7 Residue on ev
5、aporation 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 Publications referred to Inside back coverBS553:1990 ii BSI 10-1999 Foreword This British Standard, which ha
6、s been prepared under the direction of the Chemicals Standards Policy Committee, supersedes BS553:1965 which is withdrawn. In this revision of BS553 the requirements for colour, residue on evaporation and acidity have each been made more stringent and the requirement for relative density has been re
7、placed by one for density at20 C. In addition, some of the appendices describing test methods in the previous edition have been replaced by references to general test methods.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 ISO1386:1983 but is not equivalent in technical content. ISO1386 is published by the Int
8、ernational Organization for Standardization (ISO). ISO1386 lists 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 similar to
9、 those described in Appendix B and Appendix C, respectively, of this British Standard. ISO1386 does not specify limits for any of the properties of ethyl acetate or other solvent acetates. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Sta
10、ndards 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 to4, an inside back cover and a back cover. This s
11、tandard 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.BS553:1990 BSI 10-1999 1 1 Scope This British Standard specifies requirements for ethyl acetate suitable for industrial purposes. NOTEThe ti
12、tles 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 ethyl ester of acetic acid (CH 3 COOC 2 H 5 ). 3 Sampling an
13、d 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-stopped bottle, or screw-capped bottle fitted w
14、ith 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 excessive pressure
15、 changes that could arise from temperature variations during storage and handling. About10% ullage is recommended. 4 Colour The colour of the material shall not exceed10Hazen colour units when measured by the method described in BS5339. 5 Density The density of the material at20 C, measured by the m
16、ethod described in BS4522, shall be not lower than0.898g/mL and not higher than0.901g/mL. 6 Distillation range When the material is distilled by the method described in BS4591, modified as described in Appendix A, the initial boiling point at101.3kPa pressure shall be not lower than76.5 C and the dr
17、y point at101.3kPa pressure shall be not higher than78.5 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 BS4524. 8 Water content The material shall not contain more than0.10% (m/m) of water when determine
18、d by the method described in clause2 of BS2511:1970 using20mL of the material. 9 Acidity The acidity of the material, calculated as acetic acid (CH 3 COOH), shall not exceed0.0050%(m/m) when determined by the method described in Appendix B. 10 Ester content The material shall contain not less than99
19、.0% (m/m) of esters, calculated as ethyl acetate (CH 3 COOC 2 H 5 ), when determined by the method described in Appendix C. 1) Detailed information on the sampling of liquid chemical products is given in BS5309-1 and BS5309-3.BS553:1990 2 BSI 10-1999 Appendix A Determination of distillation range De
20、termine the distillation range, in terms of the initial boiling point and the dry point, by the method described in BS4591, using the following thermometer and temperature corrections. a) Thermometer (5.1.2 of BS4591:1990). Use a thermometer designated F100C/100 complying with BS593. b) Distillation
21、 (7.2 of BS4591:1990). Regulate the rate of heating so that the first drop of distillate falls from the end of the condenser after7min to12min. c) Corrections to be applied to observed temperatures (9.1.2 of BS4591:1990). If the corrected barometric pressure deviates from101.3kPa apply corrections t
22、o the observed temperatures by subtracting0.031 C for every0.1kPa above101.3kPa, or adding0.031 C for every0.1kPa below101.3kPa. NOTEThese 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 (ormethy
23、lated spirits) and titrated with standard volumetric sodium hydroxide solution, using phenolphthalein as indicator. B.2 Reagents B.2.1 General During the analysis, use only reagents of recognized analytical grade, only methylated spirits complying with BS3591, and only water complying with grade3 of
24、 BS3978. B.2.2 Ethanol or industrial methylated spirits,95% (V/V) NOTEThe use of industrial methylated spirits is governed by The Methylated Spirits Regulations,1983 (S.I.1983No.252). It is not permissible to use duty-free ethanol, received under the provisions of The Alcoholic Liquor Duties Act1979
25、, Section10, for purposes for which industrial methylated spirits is an acceptable alternative. B.2.3 Sodium hydroxide, standard 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 spi
26、rits (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 Ordinary 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
27、 an inert support (soda lime). B.3.3 Burette, of10mL capacity, graduated in0.02mL divisions, complying with class A of BS846. 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 con
28、ical flask (B.3.2), add0.5mL of the phenolphthalein solution (B.2.4) and add the sodium hydroxide solution (B.2.3) until a 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
29、, persisting for at least10s, is obtained. Stopper the flask and swirl its contents after each addition of sodium hydroxide 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. Report the result to two signifi
30、cant figures. where V 1 is the volume of the sodium hydroxide solution 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)=0.100m
31、ol/L (in g). A 0.006 V 1 50 -100 = A 0.012 V 1 - =BS553:1990 BSI 10-1999 3 B.6 Test report The test report shall include the following information: a) a complete identification of the sample; b) a reference to the method used, i.e.BS553 Appendix B; c) the results expressed in accordance withB.5; d)
32、any unusual features noted during the determination; e) any operation not included in this appendix or regarded as optional. Appendix C Determination of ester content C.1 Principle The esters present in a test portion are saponified with excess ethanolic potassium hydroxide solution and the excess i
33、s determined by titration with standard volumetric hydrochloric acid solution, using phenolphthalein as indicator. C.2 Reagents C.2.1 General During the analysis, use only reagents of recognized analytical grade, only methylated spirits complying with BS3591, and only water complying with grade3 of
34、BS3978. C.2.2 Potassium hydroxide, 56g/L solution in95% (V/V) ethanol or95% (V/V) industrial methylated spirits. NOTEThe use of industrial methylated spirits is governed by The Methylated Spirits Regulations,1983 (S.I.1983No.252). It is not permissible to use duty-free ethanol, received under the pr
35、ovisions of The Alcoholic Liquor Duties Act1979. Section10, for purposes for which industrial methylated spirits is an acceptable alternative. C.2.3 Hydrochloric acid, standard volumetric solution, c(HCl)=mol/L. C.2.4 Phenolphthalein, 5g/L ethanolic solution. Prepare as described inB.2.4. C.3 Appara
36、tus 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 reflux condensers, water-cooled, with ground glass joints to fit the conical flasks (C.3.2). C.3.4 Weighing pipette, capacity10mL. C.4 Procedure C.4.1
37、 Test portion Using the weighing pipette (C.3.4), transfer between2.0g and2.4g of the sample, weighed to the nearest0.001g, to a conical flask (C.3.2) containing50.0mL 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 pota
38、sium hydroxide solution (C.2.2), using the same one-mark pipette referred to inC.4.1, into the second conical flask(C.3.2). C.4.3 Determination Attach a reflux condenser to each conical flask and heat the two flasks for1h in a boiling-water bath. Withdraw the flasks, still carrying their condensers,
39、 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 the flask. Disconnect the flasks and wash each joint with a further20mL of water, again collecting the washings in the appropriate flask. Add0.5mL of
40、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) until the pink colour is just discharged. C.5 Expression of results The ester content E, expressed as a percentage by mass of ethyl acetate (CH 3
41、COOC 2 H 5 ), is given by the equation: i.e. Report the result to one decimal place. where V 0 is the volume of the hydrochloric acid solution used for the titration of the blank (inmL); V 1 is the volume of the hydrochloric acid solution used for the titration of the test solution (inmL); m is the
42、mass of the test portion (in g); 88.1 is the relative molecular mass of ethyl acetate. E 88.1 V 0 V 1 () 1000 m -100 = E 8.81 V 0 V 1 () m - =BS553:1990 4 BSI 10-1999 C.6 Test report The test report shall include the following information: a) a complete identification of the sample; b) a reference t
43、o the method used, i.e.BS553 Appendix C; c) the results expressed in accordance withC.5; d) any unusual features noted during the determination; e) any operation not included in this appendix orBS553:1990 BSI 10-1999 Publications referred to BS593, Specification for laboratory thermometers. BS846, S
44、pecification for burettes. BS2511, Methods for the determination of water (Karl Fischer method). BS3591, Specification for industrial methylated spirits. BS3978, Specification for water for laboratory use. BS4522, Method for determination of absolute density at20 C of liquid chemical products for in
45、dustrialuse. BS4524, Method for determination of residue on evaporation on a water bath. BS4591, Method for determination of distillation characteristics of organic liquids (other than petroleumproducts). BS5309, Methods for sampling chemical products. BS5309-1, Introduction and general principles.
46、BS5309-3, Sampling of liquids. BS5339, Method of measurement of colour in Hazen units (platinum-cobalt scale) of liquid chemicalproducts. ISO1386, Solvent acetates for industrial useMethods of test 2) . 2) Referred to in the foreword only.BS553:1990 BSI 389 Chiswick High Road London W4 4AL BSIBritis
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