BS-684-2.36-1983 ISO-6463-1982.pdf
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1、BRITISH STANDARD CONFIRMED NOVEMBER 1992 BS 684-2.36: 1983 ISO 6463:1982 Methods of analysis of Fats and fatty oils Part 2: Other methods Section 2.36 Determination of butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT) ISO title: Animal and vegetable fats and oils Determination of butylhydroxya
2、nisole (BHA) and butylhydroxytoluene (BHT) Gas-liquid chromatographic method IMPORTANT NOTE. It is essential that this Section be read in conjunction with the information in BS 684-0 “General Introduction” which is published separately. UDC 665.1.014:543.544.45:547.56 Licensed Copy: sheffieldun shef
3、fieldun, na, Wed Dec 06 13:26:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 684-2.36:1983 This British Standard, having been prepared under the direction of the Food and Agriculture Standards Committee, was published under the authority of the Board of BSI and comes into effect on 31 May 1983 BSI
4、 09-1999 The following BSI references relate to the work on this standard: Committee reference FAC/18 Draft for comment 81/51283 DC ISBN 0 580 11943 2 National foreword This Section of BS 684 was prepared under the direction of the Food and Agriculture Standards Committee and is identical with ISO 6
5、463:1982 “Animal and vegetable fats and oils Determination of butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT) Gas-liquid chromatographic method” published by the International Organization for Standardization (ISO). Terminology and conventions. The text of the International Standard has been
6、 approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is curr
7、ent practice to use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. Additional information. With reference to the note to clause 1, the method is not now considered suitable
8、 for the determination of TBHQ. There is a proposal to amend the text of the International Standard. With regard to 7.2.2.2 it is sometimes useful to use an additional solution containing 20 4g of antioxidant per millilitre. With regard to 7.2.3 it is recommended that a graph is always plotted. If t
9、he graph is a straight line, the mean value of K can be calculated. 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 immuni
10、ty from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 and 2, 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 a
11、mendment table on the inside front cover. Cross-reference International StandardCorresponding British Standard ISO 5558:1982BS 684 Methods of analysis of fats and fatty oils Section 2.33:1983 Detection and identification of antioxidants (Identical) Amendments issued since publication Amd. No.Date of
12、 issueComments Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 13:26:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 684-2.36:1983 BSI 09-1999i Contents Page National forewordInside front cover 1Scope and field of application1 2Reference1 3Principle1 4Reagents1 5Apparatus1 6Detection1 7Proce
13、dure1 8Expression of results2 9Test report2 Publication referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 13:26:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 13:26:09 GMT+00:00 2006, Uncontrolled Copy,
14、(c) BSI BS 684-2.36:1983 BSI 09-19991 1 Scope and field of application This International Standard specifies a gas-liquid chromatographic method for the determination of butylhydroxyanisole (tert-butyl-4-methoxyphenol) (BHA) and butylhydroxytoluene (2,6-di-tert-butyl-4-methylphenol) (BHT), used as a
15、ntioxidants, in animal and vegetable fats and oils. NOTEThe method also permits quantitative determination of tertiobutylhydroquinone (TBHQ). 2 Reference ISO 5558, Animal and vegetable fats and oils Detection and identification of antioxidants Thin-layer chromatographic method. 3 Principle Dissoluti
16、on of the fat or oil in a suitable solvent, direct injection into a gas chromatograph, and use of the internal standard method of calibration. 4 Reagents 4.1 Carrier gas: an inert gas (such as nitrogen, helium or argon), carefully dried and containing less than 10 mg of oxygen per kilogram. 4.2 Auxi
17、liary gases: hydrogen, minimum purity 99,9 %, free from organic compounds; air or oxygen, free from organic compounds. 4.3 Dichloromethane or, failing this, carbon disulphide, containing no impurities which could interfere with the determination of BHA or BHT by gas chromatography. WARNING Dichlorom
18、ethane and carbon disulphide are toxic. In addition, carbon disulphide is very volatile and explosive and particular care must be exercised in using it. 4.4 Methyl undecanoate, minimum purity 99 %. 4.5 Butylhydroxyanisole, minimum purity 98 %. 4.6 Butylhydroxytoluene, minimum purity 98 %. 5 Apparatu
19、s Usual laboratory equipment, and in particular: 5.1 Gas chromatograph, with a flame ionization detector and recorder, comprising: 5.1.1 Injection device, together with one of the following systems to retain the non-volatile fats and oils: a) a pre-column packed with siliconized glass wool or glass
20、beads; b) a sleeve lined with siliconized glass wool placed in the injector (only in the case of a horizontal injector). 5.1.2 Column, made of stainless steel or glass, permitting good separation of BHA and BHT, of length about 2 m and 2 to 4 mm in internal diameter, packed, for example, with 10 % m
21、ethylpolysiloxanes1)on acid-washed, silylated brick dust.2) 5.2 Volumetric flasks, of capacities 10, 20 and 100 ml. 5.3 Graduated pipettes, of capacities 1 and 2 ml. 5.4 Analytical balance 6 Detection See ISO 5558. 7 Procedure 7.1 Setting up the apparatus 7.1.1 Injection device Temperature: 250 C Th
22、e sleeve or pre-column (5.1.1) shall be removed after each day of analysis and conditioned overnight at the test temperature. NOTEVerify the proper condition of the sleeve or pre-column by passing, from time to time, a fat or oil of known composition through the chromatograph. 7.1.2 Oven and column
23、Temperature under isothermal conditions: 160 C Flow rate of carrier gas: optimum value to be established by the operator. Before first use, condition the filled columns for 24 h at 220 C with the carrier gas flowing. 7.1.3 Detector Temperature: 250 C Flow rate of auxiliary gases: hydrogen: approxima
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