BS-5711-16-1979.pdf
《BS-5711-16-1979.pdf》由会员分享,可在线阅读,更多相关《BS-5711-16-1979.pdf(8页珍藏版)》请在三一文库上搜索。
1、BRITISH STANDARD CONFIRMED AUGUST 1994 BS 5711-16: 1979 Methods of Sampling and test for glycerol Part 16: Determination of iron content NOTEIt is recommended that this Part of BS 5711 be read in conjunction with the general information given in BS 5711-0 “General introduction”, issued separately. U
2、DC 661.188.1:547.426.1:543.062:546.72 Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 15:12:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5711-16:1979 This British Standard, having been prepared under the direction of the Chemicals Standards Committee, was published under the authority of
3、the Executive Board and comes into effect on 30 November 1979 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference CIC/6 Draft for comment 75/53579 DC ISBN 0 580 10997 6 A British Standard does not purport to include all the necessary provisions of a cont
4、ract. 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 comprises a front cover, an inside front cover, pages i and ii, pages 1 and 2, an inside back c
5、over 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. Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na,
6、Mon Dec 04 15:12:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5711-16:1979 BSI 12-1999i Contents Page 1Scope and field of application1 2References1 3Principle1 4Reagents1 5Apparatus1 6Sampling1 7Procedure1 8Calculation2 9Test report2 Publications referred toInside back cover Licensed Copy: sheff
7、ieldun sheffieldun, na, Mon Dec 04 15:12:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 15:12:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5711-16:1979 BSI 12-19991 1 Scope and field of application This British Standard describes a p
8、hotometric method for the determination of the iron content of technical glycerol. 2 References The titles of the publications referred to in this standard are listed on the inside back cover. 3 Principle Dissolution of sulphated ash residues, formation of a thioglycollate complex and photometric me
9、asurement of the absorbance of the complex. 4 Reagents The reagents used shall be of recognized analytical grade. Distilled water complying with the requirements of BS 3978 or water of at least equal purity shall be used. 4.1 Potassium hydrogen sulphate, fused. 4.2 Thioglycollic acid, 10 % (m/m) rea
10、gent solution. Dilute thioglycollic acid, 90 % (m/m), 1 + 9. WARNING. Take great care not to allow concentrated thioglycollic acid to come into contact with the skin as it causes painful wounds. 4.3 Trisodium citrate dihydrate, 300 g/l reagent solution. 4.4 Hydrochloric acid, concentrated, 36 % (m/m
11、), 11N. 4.5 Ammonia, 7N reagent solution. Dilute concentrated ammonia solution, 35 % (m/m), (18N), 1 + 1.5. 4.6 Standard iron solutions: Solution A. Dissolve 0.7023 g of pure ammonium iron (II) sulphate hexahydrate FeSO4.(NH4)2SO4.6H2O in water containing 10 ml of sulphuric acid solution, 50 % (m/m)
12、, in a 1 000 ml one-mark volumetric flask, mix well and dilute to the mark with water. 1 ml N 100 4g Fe. Solution B. Transfer 25.0 ml of solution A to a 250 ml one-mark volumetric flask and dilute to the mark with water. 1 ml N 10 4g Fe. 5 Apparatus 5.1 Volumetric flasks, one-mark, 50 ml capacity, w
13、ith ground glass neck, complying with the requirements of BS 1792. 5.2 Spectrophotometer, adjusted to read at 530 nm or a photoelectric absorptiometer with a green filter transmitting from about 500 nm to 545 nm with maximum transmission at 530 nm. Cells, all glass, of such a size that the absorbanc
14、e of the solution under test lies between 0.2 and 0.8. 5.3 Nessler cylinders, 50 ml capacity, complying with the requirements of BS 612. 6 Sampling Prepare the laboratory sample as described in Part 2 of this British Standard. 7 Procedure 7.1 Preparation of the calibration curve. Dissolve 2 g of pot
15、assium hydrogen sulphate in 10 ml of water and 5 ml of the hydrochloric acid solution (4.4). Add amounts of the standard iron solution (4.6) equivalent to 0, 25, 50, 75, 100 and 125 4g of iron (Fe), and proceed as described for the test solution in 7.2. Measure the absorbances in turn against the fi
16、rst solution containing no added iron and plot the masses of iron (Fe) against absorbances. When different cell lengths are used to obtain appropriate absorbances, the calibration results should be expressed in terms of a uniform cell length. If neither a spectrophotometer nor a photoelectric absorp
17、tiometer is available, the test solution may be compared with standard iron solutions in 50 ml Nessler cylinders (5.3), or matched against a suitable colour disc in a comparator. 7.2 Measurement. To the residue obtained in the determination of sulphated ash (see Part 7 of this British Standard), add
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- BS 5711 16 1979
链接地址:https://www.31doc.com/p-3770437.html