1、BRITISH STANDARD BS 4258-2: 1989 Methods of test for Phosphoric acid (orthophosphoric acid) for industrial use Part 2: Determination of iron contentBS4258-2:1989 This British Standard, having been prepared under the directionof the Chemicals Standards Policy Committee, waspublished under the authori
2、tyof the Board of BSIandcomes into effect on 29 September 1989 BSI 02-2000 First published January 1968 First revision September 1989 The following BSI references relate to the work on this standard: Committee reference CIC/37 Draft for comment 88/51187 DC ISBN 0 580 17366 6 Committees responsible f
3、or this British Standard The preparation of this British Standard was entrusted by the Chemicals Standards Policy Committee (CIC/-) to Technical Committee CIC/37, upon which the following bodies were represented: Association of Public Analysts British Coal Corporation Chemical Industries Association
4、 Department of Trade and Industry (Laboratory of the Government Chemist) Fertiliser Manufacturers Association Ltd. Institute of Trading Standards Administration Ministry of Agriculture, Fisheries and Food Ministry of Defence Amendments issued since publication Amd. No. Date of issue CommentsBS4258-2
5、:1989 BSI 02-2000 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Principle 1 3 Reagents 1 4 Apparatus 1 5 Procedure 1 6 Calculation and expression of results 1 7 Test report 1 Publications referred to Inside back coverBS4258-2:1989 ii BSI 02-2000 Foreword This Part
6、 of BS 4258 has been prepared under the direction of the Chemicals Standards Policy Committee to provide methods for the analysis of phosphoric acid (orthophosphoric acid) for industrial use. This Part supersedes BS4285-2:1968, which is withdrawn, and from which it differs by making substantial refe
7、rence to BS6337-3, possession of which is essential, and by using1,10-phenanthroline for formation of the coloured complex rather than2,2-bipyridyl. This Part includes a procedure for the preparation of a test solution suitable for subsequent treatment and determination of iron content in accordance
8、 with the general method of BS6337-3 which reflects current practice in technique and presentation. This Part of BS 4258 is related to ISO/R849, from which it differs in the same way as from BS4258-2:1968. A British Standard does not purport to include all the necessary provisions of a contract. Use
9、rs 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, pages1 and 2, an inside back cover and a
10、 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.BS4258-2:1989 BSI 02-2000 1 1 Scope This Part of BS4258 describes a spectrometric method for determination of the iron co
11、ntent of phosphoric acid (orthophosphoric acid) for industrial use. It is applicable to products having an iron content of not lower than 20mg/kg. NOTE 1A reduced lower limit for applicability cannot be quoted for this method because of the risk of interference of phosphate in the development of col
12、our (see clause2 of BS6337-3:1983). NOTE 2The titles of the publications referred to in this standard are listed on the inside back cover. 2 Principle The principle is described in clause3 of BS6337-3:1983. 3 Reagents The reagents described in clause4 of BS6337-3:1983 and water complying with grade3
13、of BS3978are required. 4 Apparatus 4.1 General. The apparatus described inclause5 of BS6337-3:1983, together with the following, is required. 4.2 One-mark volumetric flask, 100mL, complying with BS1792, class B. 5 Procedure 5.1 Test portion and preparation of the test solution Weigh, to the nearest0
14、.0001g, a test portion of approximately1g. Transfer quantitatively to the volumetric flask (4.2) and add10mL of the hydrochloric acid (see4.1 of BS6337-3:1983). Dilute to the mark with water and mix well. NOTEIt is recommended that reference be made to the information on sampling given in BS4258-12.
15、 5.2 Determination Take an aliquot portion of the test solution not exceeding50mL in volume and not containing more than5004g of iron (expressed as Fe). Determine the iron content of this aliquot portion by following the procedure described in clause6 of BS6337-3:1983. 6 Calculation and expression o
16、f results Calculate the mass of iron in the aliquot portion of the test solution in accordance with clause7 of BS6337-3:1983. The iron content, expressed as milligrams of iron (Fe) per kilogram, is given by the following expression: where 7 Test report The test report shall include the following inf
17、ormation: a) a complete identification of the sample; b) a reference to this British Standard, i.e. BS4258-2:1989; c) the results expressed in accordance with clause6; d) details of any unusual features noted during the determination; e) any operation not included in this British Standard or regarde
18、d as optional. M 0 is the mass of the test portion (see5.1) (in g); M 1 is the mass of iron found in the aliquot portion of the test solution (see5.2) (in 4g); M 2 is the mass of iron found in the aliquot portion of the blank test solution (see6.2 of BS6337-3:1983) (in 4g); V is the volume of the al
19、iquot portion of the test solution (see5.2) (in mL).2 blankBS4258-2:1989 BSI 02-2000 Publications referred to BS 1792, Specification for one-mark volumetric flasks. BS 3978, Specification for water for laboratory use. BS 4258, Methods of test for phosphoric acid (orthophosphoric acid) for industrial
20、 use. BS 4258-12, Guide to sampling techniques. BS 6337, General methods of chemical analysis. BS 6337-3, Method for determination of iron content (1,10-phenanthroline spectrophotometric method). ISO/R 849, Phosphoric acid for industrial use Determination of iron content 2,2-Bipyridyl spectrophotome
21、tric method 1) . 1) Referred to in the foreword only.BS 4258-2: 1989 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level.
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