BRITISH STANDARD BS ENISO 11732:2005 BS 6068-2.93:2005 Water quality - Determination of ammonium nitrogen - Method by flow analysis (CFA and FIA) and spectrometric detection The European Standard EN ISO11732:2005has the status ofa British Standard ICS 13.060.50 BSi British Standards Copy, BSENISO11732:2005 Uncontrolled National foreword This British Standard is the official English language version of EN ISO 11732:2005. It is identical with iSO 11732:2005. It supersedes BS EN ISO 11732:1997 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee EH/3,Water quality,to Subcommittee EH/3/2,Physical, chemical and 12:25, biochemical methods, which has the responsibility to: aid enquirers to understand the text; 12/05/2010 present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitorrelated international and European developments and promulgate them in the UK. A list oforganizations represented on this subcommittee can be obtained on request to its secretary. / of Belfast, Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSl Catalogue under the section entitled"International Standards Correspondence Index", or by using the "Search" facility of the BSl Electronic Catalogue or of British Standards Online. Queen'sUniversity This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI Compliance with a British Standard does not of itself confer immunity from legal obligations. The s UniversityAthens, Summary of pages This document comprises a front cover, an inside front cover, the EN isO title page, the EN isO foreword page, the IsO title page, pages i to v, a blank page, pages 1 to 18, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Queens Amendments issued since publication This British Standard was published under the authority Date Comments Amd. No. of the Standards Policy and Strategy Committee on 17 February 2005 Copy: @BSI 17 February2005 Licensed ISBN 0 580 45490 8 Copy ENISO11732:2005 IS:23711 05002(E) Jncontrolled 3.2 Interferences Volatile amines, if present, diffuse through the membrane and lead to a pH shift. If the concentrations of the to pH 5,8 prior to the analysis. 2 In rare cases, it may be possible that the sample does not reach a pH of 12 after the addition of the alkaline sample shall be adjusted to the range of 3 to 5 by the addition of sodium hydroxide solution (3.3.2 or 3.3.3) addition of a suitable complexing agent, such as ethylenedinitrilotetraacetic acid (EDTA), disodium salt, to the 2 alkaline reaction solution (3.3.17) in sufficiently large concentration will prevent the interference by Cu, Zn, Fe, Belfast In the case of samples containing particulate matter, see 3.5 (last paragraph). Samples with a total salt concentration of>10g/l shall be diluted prior to the measurement of 3.3 Reagents content of the blank shall regularly be checked (3.6.3). 3.3.1 Water, of grade 1as specified in ISO 3696:1987. Queen's 3.3.2 Sodium hydroxide solution I, c(NaOH) = 5 mol/l. 3.3.3 Sodium hydroxide solution Il, c(NaOH) = 0,01 mol/l. The 3.3.4 Ethylenedinitrilotetraacetic acid (EDTA)"", disodium salt, monohydrate, C1oH14N2Na2Og·H20 3.3.5 Bromocresol purple, C21H16Br2O5S. nens, 3.3.6 Bromothymolblue, C27H28Br2O5S yAth 3.3.7 Cresol red, C21H18O5S. 3.3.8 Ammonium chloride, NH4Cl, dried at 105 °C±2C to constant mass rsit 3.3.9 Potassium chloride, KCl 3.3.10 Boric acid, H3BO3. 3.3.11 Hydrochloric acid solution I, c(HCl) = 0,01 mol/l. Queens 3.3.12 Hydrochloric acid solution Il, c(HCl) = 0,1 mol/l. 3.3.13 Hydrochloric acid solution IIl, c(HCl) = 1,0 mol/l. Copy: 3.3.14 Sulfuric acid, p(H2SO4) = 1,84 g/ml Licensed Commonlyknown