1、BRITISH STANDARD BS 552:1970 Incorporating Amendment No. 1 Specification for Amyl acetateBS552:1970 This British Standard, having been approved by the ChemicalsIndustry StandardsCommittee, was published under the authority ofthe Executive Board on 23 July 1970 BSI 11-1999 First published May 1934 Fi
2、rst revision March 1950 Second revision March 1957 Third revision July 1970 The following BSI references relate to the work on this standard: Committee references CIC/4, CIC/4/5 and CIC/51 Draft for comment 69/27346 ISBN 580 06071 3 Co-operating organizations The Chemicals Industry Standards Committ
3、ee under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Board of Trade British Steel Industry Chemical Industries Association* Department of Health and Social Security Fertilizer
4、 Manufacturers Association Ltd Gas Council Institution of Gas Engineers Ministry of Agriculture, Fisheries and Food Ministry of Technology Laboratory of the Government Chemist* National Sulphuric Acid Association Royal Institute of Public Health & Hygiene The Government department and industrial org
5、anization marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard. British Plastics Federation Ministry of Defence, Navy Department Oil and Colour Chemists Association Paintmakers Assoc
6、iation of Great Britain Pharmaceutical Society of Great Britain Research Association of British Paint, Colour and Varnish Manufacturers Royal Institute of Chemistry Society of Chemical Industry Society of Motor Manufacturers and Traders Ltd. Toilet Preparations Federation Amendments issued since pub
7、lication Amd. No. Date of issue Comments 7218 September 1992 Indicated by a sideline in the marginBS552:1970 BSI 11-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 Description 1 3 Colour 1 4 Relative density 1 5 Distillation yield 1 6 Residue on evaporation
8、 1 7 Water 1 8 Acidity 1 9 Ester content 1 10 Sampling and size of sample 1 Appendix A Limit test for colour 2 Appendix B Method for the determination of distillation yield 2 Appendix C Method for the determination of residue on evaporation 3 Appendix D Method for the determination of acidity 3 Appe
9、ndix E Method for the determination of ester content 4BS552:1970 ii BSI 11-1999 Foreword This standard makes reference to the following British Standards: BS 593, Laboratory thermometers. BS 612, Nessler cylinders. BS 658, Apparatus for the determination of distillation range. BS 1792, One-mark volu
10、metric flasks. BS 2511, Methods for the determination of water (Karl Fischer method). BS 3591, Industrial methylated spirits. BS 3978, Water for laboratory use. BS 4591, Method for determination of distillation characteristics of organic liquids (other than petroleum products). This standard forms o
11、ne of a series of British Standards for solvents and allied products, the preparation of which was authorized originally by the Fine Chemicals Industry Standards Committee (now merged in the Chemicals Industry Standards Committee). This British Standard was first issued in1934, and was last revised
12、in1957. In the present revision a limit for colour has been introduced. The opportunity has been taken to clarify the wording of the standard and to bring it into line with current conventions. A British Standard does not purport to include all the necessary provisions of a contract. Users of Britis
13、h 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 and a back cover. This standard has been
14、 updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS552:1970 BSI 11-1999 1 1 Scope This British Standard specifies requirements for amyl acetate suitable for industrial purposes. 2 Description British Stand
15、ard amyl acetate shall be clear and free from matter in suspension, and shall consist essentially of the acetic esters of amyl alcohols, mixtures thereof, or alcohols obtained from fusel oil. 3 Colour The colour of the material shall not exceed15Hazen units when measured by the method described in A
16、ppendix A or by a suitable instrumental method. 4 Relative density The relative density 1)of the material at any one of the following temperatures shall be within the appropriate values as shown: 5 Distillation yield The material, on distillation by the method described in Appendix B, shall yield at
17、101.3kN/m 22)(760 mmHg) pressure not less than95% by volume between120 C and145 C and not more than67% by volume below135 C. 6 Residue on evaporation The material shall not leave more than0.01%by mass of residue when tested by the method described in Appendix C. 7 Water The material shall not contai
18、n more than0.3%by mass of water, determined by the method described in clause2 of BS 2511:1970 3)and using20ml of the material. 8 Acidity The material shall not contain more than0.01% by mass of acid, calculated as acetic acid, CH 3 COOH, and determined by the method described in Appendix D. 9 Ester
19、 content The ester content of the material shall be not less than95% by mass, calculated as amyl acetate, CH 3 COOC 5 H 11 , and determined by the method described in Appendix E. 10 Sampling and size of sample A representative sample of the material measuring not less than half a litre shall be take
20、n from the bulk for the purpose of examination in accordance with this standard. The sample shall be placed in a clean, dry and airtight glass-stoppered bottle of such a size that it is nearly filled by the sample. When it is necessary to seal the container, care shall be taken to avoid the risk of
21、contaminating the contents in any way. 1) Ratio of the density of a liquid at a specified temperature to the density of water at a specified temperature. Temperature Relative density C min. max. 20/4 0.866 0.874 20/20 0.868 0.876 25/25 0.864 0.872 2) 1 kN/m 2= 10 mbar = 7.5 mmHg. 3) BS 2511:1970 Met
22、hods for the determination of water (Karl Fisher method).BS552:1970 2 BSI 11-1999 Appendix A Limit test for colour A.1 Apparatus The apparatus required comprises: 1) Matched Nessler cylinders 4) , two of100ml capacity. 2) One-mark volumetric flasks 5) , one of250ml capacity and one of500ml capacity.
23、 A.2 Reagents The reagents used shall be of a recognized analytical reagent quality. Water complying with BS 3978 6)shall be used throughout. 1) Cobaltous chloride, hexahydrate. 2) Hydrochloric acid, concentrated, 36% m/m (11N). Either 3) Chloroplatinic acid reagent. Dissolve 250 mg of platinum in a
24、 small quantity of aqua regia contained in a glass or porcelain basin by heating on a water bath. When the metal has dissolved evaporate the solution to dryness. Add1ml of the hydrochloric acid and again evaporate to dryness. Repeat this operation twice more. or 4) Potassium chloroplatinate A.3 Prep
25、aration of colour standard Dissolve0.5g of the cobaltous chloride hexahydrate and either the whole of the chloroplatinic acid (prepared as described above) or2.490g of potassium chloroplatinate, in50ml of the hydrochloric acid. Warm, if necessary, to obtain a clear solution and after, cooling, pour
26、into the500ml volumetric flask. Dilute with water to the mark. Pipette 7.5ml of this solution into the250ml volumetric flask. Dilute with water to the mark. This diluted solution has a colour of15Hazen units and should always be freshly prepared. A.4 Procedure Fill one of the Nessler cylinders to th
27、e mark with the sample, and the other with the colour standard. Using a white background, compare the colours. Appendix B Method for the determination of distillation yield B.1 Apparatus The apparatus required is described in BS 658 7)and comprises: 1) Distillation flask of 150 ml distillation capac
28、ity complying with the requirements of BS 658 7) . 2) Thermometer, No. F255C/100, complying with the requirements of BS593 8) . 3) Receiver, Type 1, of 100 ml capacity, complying with the requirements of BS658 7) . 4) Condenser, Type 1, complying with the requirements of BS658 7) . 5) Draught screen
29、, Type B, complying with the requirements of BS 658 7) . B.2 Corrections to be applied to the specified distillation temperatures before commencing the distillation B.2.1 Read the barometer and correct the reading as described in clause8 of BS 4591:1990 9) . B.2.2 When the corrected barometric press
30、ure deviates from101.3kN/m 210)(760mmHg), apply corrections to the specified distillation temperatures by adding0.36 C for every1kN/m 2above101.3kN/m 2 (0.047 C per millimetre of mercury) or subtracting0.36 C for every1kN/m 2below101.3kN/m 2(0.047 C per millimetre of mercury). NOTEThese corrections
31、are valid only for pressure above93kN/m 2(700mmHg). B.2.3 If the thermometer gives incorrect readings at the corrected specified distillation temperatures, further adjust the latter by adding the amount of error if the thermometer is reading high, or subtracting the amount of error if the thermomete
32、r is reading low. 4) BS 612, “Nessler cylinders”. 5) BS 1792, “One-mark volumetric flasks”. 6) BS 3978, “Water for laboratory use”. 7) BS 658, “Apparatus for the determination of distillation range (including flasks and receiver)”. 8) BS 593, “Laboratory thermometers”. 9) BS 4591:1990, Method for de
33、termination of distillation characteristics of organic liquids (other than petroleum products). 10) 1 kN/m 2= 10 mbar = 7.5 mmHg.BS552:1970 BSI 11-1999 3 B.3 Procedure Assemble the apparatus as described in BS 658 7) . Measure100ml of the sample in the receiver. Transfer the sample as completely as
34、possible to the distillation flask and add a few anti-bumping granules. Place the flask, thermometer and receiver in position and ensure that the condenser has a steady supply of water. Adjust the rate of heating so that the first drop of distillate falls from the end of the condenser in10to15minute
35、s. Further adjust the rate of heating so that the distillate is collected at the rate of3ml to4ml per minute. Read the volume of distillate in the receiver when the thermometer indicates each of the corrected specified distillation temperatures and express the volumes so recorded as percentages by v
36、olume. Appendix C Method for the determination of residue on evaporation C.1 Procedure Pipette 100 ml of the sample into a weighed glass evaporating dish on a boiling water bath. Blow a stream of filtered air onto the surface of the liquid from a jet1mm in diameter, with the tip of the jet10mm above
37、 the edge of the dish and under a pressure of0.5kN/m 2(50mm of water). Evaporate the sample to dryness and dry the residue for one hour in an oven, at a temperature of105 5 C. Cool in a desiccator and weigh. Dry the residue in the oven again for30minutes, cool in a desiccator and weigh again. Repeat
38、, if necessary, until two successive weighings do not differ by more than1mg. C.2 Calculation Residue on evaporation, per cent by mass Appendix D Method for the determination of acidity D.1 Reagents The reagents used shall be of a recognized analytical reagent quality. Water complying with BS 3978 1
39、1)shall be used throughout. 1) Sodium hydroxide, 0.1N solution. 2) Ethanol 12) , 95% (v/v). 3) Phenolphthalein indicator solution, 10 g/l. Dissolve 2.5 g of phenolphthalein in250ml of ethanol 12) 95% (v/v), and make faintly pink by the addition of dilute sodium hydroxide solution. D.2 Procedure Take
40、 50 ml of the ethanol, add 0.5ml of the phenolphthalein indicator and neutralize with sodium hydroxide solution. Add50ml of the sample and titrate the mixture immediately with the0.1n sodium hydroxide solution until the first pink colour persists for at least10seconds. D.3 Calculation Acidity, calcu
41、lated as acetic acid, CH 3 COOH, per cent by mass where M = mass, in grammes, of residue and d = relative density of the sample.M d - = 11) BS 3978, “Water for laboratory use”. 12) Ethanol may be replaced by industrial methylated spirits,95% (v/v), complying with the requirements of BS3591. It shoul
42、d be noted that the 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, Section 10, for purposes for which industrial methyla
43、ted spirits is an acceptable alternative. where V 1= volume, in millilitres, of 0.1N sodium hydroxide used and d = relative density of the sample. 0.012V 1 d - =BS552:1970 4 BSI 11-1999 Appendix E Method for the determination of ester content E.1 Reagents The reagents used shall be of a recognized a
44、nalytical reagent quality. Water complying with BS 3978 13)shall be used throughout, and shall be freshly boiled and cooled. 1) Potassium hydroxide, approximately N solution in95% (v/v) ethanol 14) . 2) Hydrochloric acid, N solution. 3) Phenolphthalein indicator solution, 10 g/l. Dissolve 2.5 g of p
45、henolphthalein in250ml of ethanol 14) ,95% (v/v) and make faintly pink by the addition of dilute sodium hydroxide solution. E.2 Procedure Measure 50.0 ml of the potassium hydroxide solution into each of two dry250ml conical flasks with ground glass jointed stoppers. Close the flasks with their glass
46、 stoppers. Transfer by means of a weighing pipette between 3.0g and3.5g of the sample (weighed to the nearest 0.001g) into one of the flasks. Attach the flasks to water-cooled reflux condensers with ground glass joints, and heat for one hour in a boiling-water bath. Withdraw the flasks, still carryi
47、ng their condensers, and immerse them in cold running water. When cool, wash down the inside of each condenser with two20ml portions of water. Disconnect the flasks and wash each joint with a further20ml of the water. Add 0.5ml of phenolphthalein indicator and titrate the mixture immediately with th
48、e N hydrochloric acid solution until the pink colour is just discharged. E.3 Calculation Ester content, calculated as amyl acetate, CH 3 COOC 5 H 11 , 13) BS 3978, “Water for laboratory use”. 14) Ethanol may be replaced by industrial methylated spirits, 95% (v/v), complying with the requirements of
49、BS3591. It should be noted that the 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 Act 1979, Section10, for purposes for which industrial methylated spirits is an acceptable alternative. where V 2 = volume, in millilitres, of N hydrochloric acid solution required by blank, V 3 = volume, in millilitres, of N hydrochloric acid solution required by sample and M 2 =
