1、BRITISH STANDARD CONFIRMED JUNE 1990 BS 508-2: 1984 Butan-1-ol for industrial use Part 2: Methods of test UDC 661.725.4:543.062BS508-2:1984 This British Standard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authority ofthe Board of BSI and co
2、mes into effect on 31 October 1984 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference CIC/4 Draft for comment 80/51210 DC ISBN 0 580 14084 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the C
3、hemicals Standards Committee (CIC/-) to Technical Committee CIC/4 upon which the following bodies were represented: Chemical Industries Association Ministry of Defence Oil and Colour Chemists Association Royal Society of Chemistry Society of Chemical Industry The following bodies were also represent
4、ed in the drafting of the standard, through subcommittees and panels: British Pharmacopoeia Commission British Society of Perfumers Cosmetic, Toiletry and Perfumery Association Limited Department of Trade and Industry (Laboratory of the Government Chemist) Amendments issued since publication Amd. No
5、. Date of issue CommentsBS508-2:1984 BSI 10-1999 i Content Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Sampling 1 3 Determination of density at 20 C 1 4 Determination of distillation characteristics 1 5 Determination of residue on evaporation on a water bath 1 6 Determinat
6、ion of bromine number 1 7 Measurement of colour 1 8 Determination of water content 1 9 Determination of aldehydes and ketones content 1 10 Determination of acidity 2 11 Test reports 3 Publications referred to Inside back coverBS508-2:1984 ii BSI 10-1999 Foreword This Part of this British Standard, w
7、hich has been prepared under the direction of the Chemicals Standards Committee, provides a comprehensive series of test methods for butan-1-ol for industrial use. Although applicable to the material in general, it includes all the test methods required to assess compliance with BS508-1. The standar
8、d previously numbered BS 508 (published in 1966) has been amended to become BS 508-1 “Specification” and the methods of test that were included in the appendices have been deleted. In preparing this standard, the opportunity has been taken to implement Parts 1 and 2 of ISO 755 “Butan-1-ol for indust
9、rial use Methods of test”, published by the International Organization for Standardization (ISO). Part 3, although approved by the UK, is not to be implemented as there is no UK requirement for the test method. These standards have been prepared, with the active participation of the UK, by Technical
10、 Committee 47, Chemistry, of the International Organization for Standardization (ISO), as separate parts of ISO755 and constitute the revision of ISO Recommendation R 755. Subsequent International Standards in the ISO 755 series, if approved by the UK, will be published as additions to this British
11、Standard, without technical alteration. Clauses2 to9 and clause11 of this British Standard are related to ISO 755-1 but not equivalent in technical content. The technical differences occur in the method for the determination of aldehydes and ketones content (see clause9): in this British Standard on
12、ly one concentration of potassium hydroxide solution is allowed for the titration and only one form of expression of the results (as a percentage by mass calculated as butyraldehyde) is given. ISO 755-1 refers to the general method described in ISO 1843-3 for the determination of aldehydes and keton
13、es content, and gives the additional information needed to carry out the determination for butan-1-ol: in this British Standard, the method is described in full. Clause10 of this standard, which describes a method for the determination of acidity, is equivalent to ISO755-2 in technical content but d
14、iffers in presentation. This Part of this standard describes methods of test only and should not be referred to as a specification defining limits of purity. Reference to this Part of this standard should indicate that the methods of test used are in accordance with the appropriate clause(s) of BS50
15、8-2. A British Standard does not purport to include all the necessary provisions of a contract. Users of British 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 compr
16、ises a front cover, an inside front cover, pages i and ii, pages1 to 4, an inside back cover and a back cover. This 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.BS508-2:1984 BSI 10-199
17、9 1 1 Scope This Part of this British Standard describes methods for testing butan-1-ol for industrial use. NOTEThe titles of the publications referred to in this standard are listed on inside back cover. 2 Sampling 1) Store the laboratory sample in a clean, dry and airtight, ground glass stoppered
18、bottle, or a screw-capped bottle fitted with a polyethylene cone insert, of such capacity that it is almost filled by the sample. Sufficient ullage should be left in the bottle to avoid excessive pressure changes that could arise from temperature variations during storage and handling. About10% ulla
19、ge is recommended. If it is necessary to seal the bottle, take care to avoid any risk of contamination of the contents. Store the sample in a cool place in the dark. 3 Determination of density at 20 C Determine the density at 20 C by the method described in BS4522. 4 Determination of distillation ch
20、aracteristics Determine the distillation characteristics by the method described in BS4591, except that the following thermometer, temperature corrections and distillation conditions shall be used. a) Thermometer (3.2 of BS4591:1971). Use a thermometer designated F150C/100 complying with the require
21、ments of BS593. b) Corrections to be applied to observed temperatures (7.2 of BS4591:1971). If the corrected barometric pressure deviates from1013mbar 2)apply a correction to the observed temperature by subtracting0.028 C for every millibar above, or adding0.028 C for every millibar below,1013mbar.
22、c) Distillation (6.1 of BS4591:1971). Regulate the rate of heating so that the first drop of distillate falls from the end of the condenser after10to15min. 5 Determination of residue on evaporation on a water bath Determine the residue on evaporation by the method described in BS4524. 6 Determinatio
23、n of bromine number Determine the bromine number (bromine index) by the method described in BS4523. 7 Measurement of colour Determine the colour by the method described in BS5339. 8 Determination of water content Determine the water content by one of the methods described in BS2511. 9 Determination
24、of aldehydes and ketones content NOTEThis method is based on ISO1843-3 which is to be implemented as part of the revision of BS4583:1970. 9.1 Principle Reaction of carbonyl compounds present in a test portion with hydroxylammonium chloride to form an oxime, and potentiometric titration of the hydroc
25、hloric acid liberated with standard volumetric ethanolic potassium hydroxide solution. 9.2 Reagents 9.2.1 General. During the analysis, use only reagents of recognized analytical grade and only water complying with BS3978. NOTEThe ethanol specified in9.2.2 and9.2.4 may be replaced for these purposes
26、 by industrial methylated spirits,95% (V/V) complying with 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
27、Liquor Duties Act1979, Section10, for purposes for which industrial methylated spirits is an acceptable alternative to ethanol. 9.2.2 Hydroxylammonium chloride,10g/L ethanolic solution. Dissolve50g of hydroxylammonium chloride (NH 2 OH.HCl) in90mL of water and dilute to1000mL with95% (V/V) ethanol.
28、Further dilute100mL of this solution to500mL with95%(V/V) ethanol. WARNING. Hydroxylammonium chloride is toxic, corrosive and an irritant. Avoid contact with eyes and skin. 1) Additional guidance is given in BS5309-1 and BS5309-3. 2) 1 mbar =100N/m 2= 100 Pa.BS508-2:1984 2 BSI 10-1999 9.2.3 Ethanol,
29、 anhydrous, carbonyl-free, prepared as follows. Boil under reflux500mL of anhydrous ethanol with5g of2,4-dinitrophenylhydrazine and5drops of hydrochloric acid solution, approximately1.19g/mL, for2to3h. Distil off the ethanol slowly using a Widmer distillation column about300mm long and about25mm in
30、diameter, or any other suitable column. Reject the first50mL of distillate and collect the next400mL, rejecting the remainder. If the distillate is found to be coloured, carry out a redistillation. 9.2.4 Potassium hydroxide, standard volumetric solution in95% (V/V) ethanol, c (KOH) =0.1mol/L. 9.3 Ap
31、paratus 9.3.1 Ordinary laboratory apparatus 9.3.2 Two conical flasks, of borosilicate glass, of capacity250mL, fitted with ground glass stoppers. 9.3.3 Two water-cooled reflux condensers, with ground glass joints to fit the flasks (9.3.2). 9.3.4 pH meter, fitted with a glass measuring electrode and
32、a calomel reference electrode. 9.4 Procedure 9.4.1 Test portion. Into one of the conical flasks(9.3.2) already containing10mL of the hydroxylammonium chloride solution (9.2.2) weigh, to the nearest0.001g,25g to30g of the laboratory sample. 9.4.2 Blank test. Carry out a blank test at the same time as
33、 the determination, following the same procedure but omitting the test portion. 9.4.3 Determination. Add10mL of the ethanol(9.2.3) to the conical flask (9.3.2) containing the test portion (9.4.1). Attach one of the condensers(9.3.3) to the flask and reflux for30min on a boiling water bath. Remove th
34、e flask, still carrying its condenser, from the boiling water bath and allow to cool to ambient temperature. When cold, wash down the inside of the condenser with10mL of the ethanol. Transfer the contents of the flask quantitatively to a400mL beaker, washing with125mL of the ethanol. Titrate with th
35、e potassium hydroxide solution(9.2.4) using the pH meter (9.3.4). The volume/potential graph may be plotted directly, in which case the point of inflection corresponds to the end-point of the titration (pH value about3). Alternatively, the first derived curve may be plotted, in which case the end-po
36、int of the titration corresponds to the turning point of the curve. 9.5 Expression of results The aldehydes and ketones content, expressed as a percentage by mass of butyraldehyde (C 3 H 7 CHO), is given by the formula where 10 Determination of acidity 10.1 Principle Titration of the acidity of a te
37、st portion with a standard volumetric sodium hydroxide solution, using phenolphthalein as indicator. 10.2 Reagents 10.2.1 General. During the analysis, use only reagents of recognized analytical grade and only water complying with BS3978. 10.2.2 Sodium hydroxide, standard volumetric solution, c (NaO
38、H) =0.1mol/L. 10.2.3 Phenolphthalein,5g/L ethanolic solution. Dissolve0.5g of phenolphthalein in100mL of95%(V/V) ethanol, and add the sodium hydroxide solution (10.2.2) until a pale pink colouration is obtained. NOTEThe ethanol may be replaced for this purpose by industrial methylated spirits,95% (V
39、/V) complying with 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 Act1979, Section10, for pur
40、poses for which industrial methylated spirits is an acceptable alternative to ethanol. 10.3 Apparatus 10.3.1 Ordinary laboratory apparatus 10.3.2 Conical flask, of capacity250mL, of borosilicate glass, fitted with a ground glass stopper. 10.3.3 Burette, of capacity10mL, graduated in0.02mL divisions,
41、 complying with class A of BS846. 10.4 Procedure 10.4.1 Test portion. Weigh, in the conical flask(10.3.2),100 0.1g of the laboratory sample. V 0 is the volume of the potassium hydroxide solution used for the blank test (in mL); V 1 is the volume of the potassium hydroxide solution used for the deter
42、mination (inmL); m is the mass of the test portion (in g). 0.72 V 1 V 0 () m -BS508-2:1984 BSI 10-1999 3 10.4.2 Determination. Add0.5mL of the phenolphthalein solution (10.2.3) to the flask containing the test portion (10.4.1) and titrate with the sodium hydroxide solution (10.2.2) until the pink co
43、lour remains for15s. Shake the contents of the flask, with the stopper in position, after each addition of sodium hydroxide solution. 10.5 Expression of results The acidity, expressed as a percentage by mass of butyric acid (C 3 H 7 COOH), is given by the formula where NOTEIf the standard volumetric
44、 solution used does not have exactly the concentration stated in the list of reagents, an appropriate correction should be applied. 11 Test reports The test report, for each determination, should contain the following: a) an identification of the sample; b) a reference to the method used; c) the res
45、ults, and the method of expression used; d) any unusual features noted during the determination; e) any operation not included in the appropriate clause of this standard or in the British Standards to which reference is made, or regarded as optional. V is the volume of the sodium hydroxide solution
46、used for the determination (inmL); m is the mass of the test portion (in g); 0.0088is the mass (in g) of butyric acid corresponding to1mL of sodium hydroxide solution, c (NaOH) =0.100mol/L. 0.008 8V 100 m - 0.88V m - =4 blankBS508-2:1984 BSI 10-1999 Publications referred to BS 593, Laboratory thermo
47、meters. BS 846, Specification for burettes. BS 2511, Methods for the determination of water (Karl Fischer method). BS 3591, Industrial methylated spirits. BS 3978, Water for laboratory use. BS 4522, Method for the determination of density of liquids at 20 C. BS 4523, Method for the determination of
48、bromine index. BS 4524, Method for determination of residue on evaporation on a water bath. BS 4583, Methods of test for higher alcohols. BS 4591, Method for the determination of distillation characteristics. BS 5309, Methods for sampling chemical products. BS 5309-1, Introduction and general princi
49、ples. BS 5309-3, Sampling of liquids. BS 5339, Method of measurement of colour in Hazen units (platinum-cobalt scale) of liquid chemical products. ISO 755, Butan-1-ol for industrial use Methods of test. ISO 755-1, General 3) . ISO 755-2, Determination of acidity Titrimetric method 3) . ISO 755-3, Sulphuric acid colour test 3) . ISO 1843-3, Higher alcohols for industrial use Methods of test Part III: Determination of carbonyl compounds content Potentiometric method. 3) Refer
