1、BRITISH STANDARD BS 1834:1968 Incorporating Amendment No. 1 Specification for isoPropyl acetateBS1834:1968 This British Standard, having been approved by the ChemicalsIndustry Standards Committee and endorsed by theChairman of the Chemical Divisional Council, was publishedunder the authority ofthe G
2、eneral Council on 22February1968 BSI 12-1999 First published February 1952 First revision February 1968 The following BSI references relate to the work on this standard: Committee references CIC/4, CIC/4/5 and CIC/51 Draft for comment 67/11227 ISBN 580 00082 6 Co-operating organizations The Chemical
3、s Industry Standards Committee, 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 Iron and then add0.01N sodium hydroxide solution until faintly pink; n
4、eutralize the ethanol by adding0.01N hydrochloric acid until the pink colour is just discharged. 3) Phenolphthalein indicator. Dissolve0.5g of phenolphthalein in100ml of95% (v/v) ethanol 10)and make faintly pink by the addition of dilute sodium hydroxide solution. D.2 Procedure To50ml of the sample
5、add50ml of the neutralized ethanol containing a few drops of the phenolphthalein indicator. Titrate with the0.1N sodium hydroxide solution using a microburette. D.3 Calculation Acidity, calculated as acetic acid, CH 3 COOH, parts per million by mass = 8) BS 4591:1990, Method for determination of dis
6、tillation characteristics of organic liquids (other than petroleum products). where M 1 = mass, in grammes, of residue and d = relative density of the sample. 9) BS 3978, “Water for laboratory use”. 10) Ethanol may be replaced by industrial methylated spirits,95% (v/v), complying with the requiremen
7、ts of BS3591. It should be noted that the use of industrial spirits 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 Act1979, Section10, for purposes for which indus
8、trial methylated spirits is an acceptable alternative. where T 1 = volume, in millilitres, of0.1N sodium hydroxide solution used and d = relative density of the sample. M 1 10000 d - 120 T 1 d -BS1834:1968 4 BSI 12-1999 Appendix E Method for the determination of ester content E.1 Reagents The reagen
9、ts used shall be of a recognized analytical reagent quality. Water complying with BS3978 11)shall be used throughout and shall be freshly boiled and cooled. 1) Potassium hydroxide, approximately N solution in ethanol. 12) 2) Hydrochloric acid, N solution. 3) Phenolphthalein indicator. Dissolve0.5g o
10、f phenolphthalein in100ml of95% (v/v) ethanol 12)and make faintly pink by the addition of 0.1N sodium hydroxide solution. E.2 Procedure Using the same pipette, introduce50.0ml of the potassium hydroxide solution into each of two dry250ml conical flasks with ground-glass joints. Add5ml of water to ea
11、ch flask. Close the flasks with their glass stoppers. By means of a weighing pipette, transfer2.4g to2.6g of the sample, weighed to the nearest0.001g, 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. W
12、ithdraw 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. Disconnect the flasks and wash each joint with a further20ml of water. Add0.5ml of the phenolphthalein indicator and titrate
13、the mixture immediately with the hydrochloric acid until the pink colour is just discharged. E.3 Calculation Ester content, calculated as isopropyl acetate, CH 3 COOCH(CH 3 ) 2 , per cent by mass = 11) BS 3978, “Water for laboratory use”. 12) Ethanol may be replaced by industrial methylated spirits,
14、95% (v/v), complying with the requirements of BS3591. It should be noted that the use of industrial spirits 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 Act1979,
15、 Section10, for purposes for which industrial methylated spirits is an acceptable alternative. where T 3 = volume, in millilitres, of N hydrochloric acid solution required by the blank, T 2 = volume, in millilitres, of N hydrochloric acid solution required by the test sample and M 2 = mass, in grammes, of sample taken. 10.21T 3 T 2 () M 2 -
