1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 0-626-18875-X SANS 11732:2006Edition 2ISO 11732:2005Edition 2 SOUTH AFRICAN NATIONAL STANDARD Water quality Determination of ammonium nitrogen Metho
4、d by flow analysis (CFA and FIA) and spectrometric detection This national standard is the identical implementation of ISO 11732:2005 and is adopted with the permission of the International Organization for Standardization. Published by Standards South Africa 1 dr lategan road groenkloof private bag
5、 x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 11732:2006 Edition 2 ISO 11732:2005 Edition 2 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee StanSA
6、 SC 5140.19A, Water Water sampling and analysis, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This standard was published in December 2006. This SANS edition cancels and replaces the first SABS edition (SABS ISO 11732:1997). Reference
7、numberISO 11732:2005(E)ISO 2005INTERNATIONAL STANDARD ISO11732Second edition2005-02-01Water quality Determination of ammonium nitrogen Method by flow analysis (CFA and FIA) and spectrometric detection Qualit de leau Dosage de lazote ammoniacal Mthode par analyse en flux (CFA et FIA) et dtection spec
8、tromtrique SANS 11732:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 11732:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall
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13、 www.iso.org Published in Switzerland ii ISO 2005 All rights reservedSANS 11732:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 11732:2005(E) ISO 2005 All rights reserved iiiContents Page Foreword iv Introduction v 1 Scope 1 2 Normati
14、ve references . 1 3 Determination of ammonium nitrogen by flow injection analysis (FIA) and spectrometric detection 1 4 Determination of ammonium nitrogen by continuous flow analysis (CFA) and spectrometric detection . 7 5 Calculation. 10 6 Precision 10 7 Test report . 11 Annex A (informative) Examp
15、les of flow analysis systems . 12 Annex B (informative) Precision data. 16 Bibliography . 18 SANS 11732:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 11732:2005(E) iv ISO 2005 All rights reservedForeword ISO (the International Organ
16、ization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been establish
17、ed has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
18、 International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Pu
19、blication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such paten
20、t rights. ISO 11732 was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2, Physical, chemical and biochemical methods. This second edition cancels and replaces the first edition (ISO 11732:1997), which has been technically revised. SANS 11732:2006This s tandard may only be
21、 used and printed by approved subscription and freemailing clients of the SABS .ISO 11732:2005(E) ISO 2005 All rights reserved vIntroduction Methods using flow analysis are automating wet chemical procedures and are therefore particularly suitable for the processing of large sample series at a high
22、analysis frequency (up to 100 samples per hour). It is differentiated between flow injection analysis (FIA)1,2and continuous flow analysis (CFA)3. Both methods consist of the automatic dosage of the sample introduced into a flow system (manifold) in which the sample analytes react with the reagent s
23、olutions on their way through the manifold. The sample preparation may be integrated into the manifold. The reaction product is measured in a flow detector. The user should be aware that particular problems could require the specification of additional marginal conditions. SANS 11732:2006This s tand
24、ard may only be used and printed by approved subscription and freemailing clients of the SABS .SANS 11732:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .INTERNATIONAL STANDARD ISO 11732:2005(E) ISO 2005 All rights reserved 1Water quality
25、 Determination of ammonium nitrogen Method by flow analysis (CFA and FIA) and spectrometric detection WARNING Persons using this International Standard should be familiar with normal laboratory practice. This International Standard does not purport to address all of the safety problems, if any, asso
26、ciated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions. IMPORTANT It is absolutely essential that tests conducted according to this standard be carried out by suitably trained sta
27、ff. 1 Scope This International Standard specifies methods suitable for the determination of ammonium nitrogen in various types of waters (such as ground, drinking, surface, and waste waters) in mass concentrations ranging from 0,1 mg/l to 10 mg/l (in the undiluted sample), applying either FIA (Claus
28、e 3) or CFA (Clause 4). In particular cases, the range of application may be adapted by varying the operating conditions. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undate
29、d references, the latest edition of the referenced document (including any amendments) applies. ISO 3696:1987, Water for analytical laboratory use Specification and test methods ISO 5667-1, Water quality Sampling Part 1: Guidance on the design of sampling programmes ISO 5667-2, Water quality Samplin
30、g Part 2: Guidance on sampling techniques ISO 5667-3, Water quality Sampling Part 3: Guidance on the preservation and handling of water samples ISO 8466-1, Water quality Calibration and evaluation of analytical methods and estimation of performance characteristics Part 1: Statistical evaluation of t
31、he linear calibration function 3 Determination of ammonium nitrogen by flow injection analysis (FIA) and spectrometric detection 3.1 Principle The sample containing ammonium is injected into a continuous carrier stream by means of an injection valve and is mixed with a continuously streaming flow of
32、 an alkaline solution. The ammonia formed is separated in a diffusion cell from the solution over a hydrophobic semipermeable membrane and taken up by a streaming recipient flow containing a pH indicator. Due to the resulting pH shift, the indicator solution will change its colour which is measured
33、continuously in the flow photometer. Additional information about this analytical technique is given in references 4, 5, 6, 7 and 8. NOTE Equipment following this principle using CFA instead of FIA is commercially available, however it has not been validated. SANS 11732:2006This s tandard may only b
34、e used and printed by approved subscription and freemailing clients of the SABS .ISO 11732:2005(E) 2 ISO 2005 All rights reserved3.2 Interferences Volatile amines, if present, diffuse through the membrane and lead to a pH shift. If the concentrations of the volatile amines (e.g. methylamine or ethyl
35、amine) are equal to those of the ammonium, higher results may then be expected 12. Significant concentrations of volatile amines can be reduced by distilling the sample adjusted to pH 5,8 prior to the analysis. In rare cases, it may be possible that the sample does not reach a pH of 12 after the add
36、ition of the alkaline reagent solution, thus leading to a loss of ammonium because it will not be converted quantitatively into ammonia. This may particularly occur with strong acidic or buffered samples. In these cases, the pH of the sample shall be adjusted to the range of 3 to 5 by the addition o
37、f sodium hydroxide solution (3.3.2 or 3.3.3). A high concentration of metal ions that can precipitate as hydroxides will give poorly reproducible results. The addition of a suitable complexing agent, such as ethylenedinitrilotetraacetic acid (EDTA), disodium salt, to the alkaline reaction solution (
38、3.3.17) in sufficiently large concentration will prevent the interference by Cu, Zn, Fe, Ca, Mg, and Al. A concentration of 30 g/l of ethylenedinitrilotetraacetic acid, disodium salt (3.3.4), in solution R1 (3.3.17) is adequate for metal concentrations up to 0,2 mg/l each. In the case of samples con
39、taining particulate matter, see 3.5 (last paragraph). Samples with a total salt concentration of 10 g/l shall be diluted prior to the measurement. 3.3 Reagents Apart from the reagents dealt with in the 3.3.6 and 3.3.7, use only reagents of “analytical grade quality for the determination of nitrogen”
40、, or, if not available, those of recognized “analytical grade quality”. The ammonium content of the blank shall regularly be checked (3.6.3). 3.3.1 Water, of grade 1 as specified in ISO 3696:1987. 3.3.2 Sodium hydroxide solution I, c(NaOH) = 5 mol/l. 3.3.3 Sodium hydroxide solution II, c(NaOH) = 0,0
41、1 mol/l. 3.3.4 Ethylenedinitrilotetraacetic acid (EDTA)1), disodium salt, monohydrate, C10H14N2Na2O8H2O. 3.3.5 Bromocresol purple, C21H16Br2O5S. 3.3.6 Bromothymol blue, C27H28Br2O5S. 3.3.7 Cresol red, C21H18O5S. 3.3.8 Ammonium chloride, NH4Cl, dried at 105 C 2 C to constant mass. 3.3.9 Potassium chl
42、oride, KCl. 3.3.10 Boric acid, H3BO3. 3.3.11 Hydrochloric acid solution I, c(HCl) = 0,01 mol/l. 3.3.12 Hydrochloric acid solution II, c(HCl) = 0,1 mol/l. 3.3.13 Hydrochloric acid solution III, c(HCl) = 1,0 mol/l. 3.3.14 Sulfuric acid, (H2SO4) = 1,84 g/ml. 1) Commonly known as ethylenediaminetetraace
43、tic acid. SANS 11732:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 11732:2005(E) ISO 2005 All rights reserved 33.3.15 Mixed indicator. In a mortar prepare a dry mixture consisting of 10 g of bromocresol purple (3.3.5), 5 g of bromot
44、hymol blue (3.3.6), 2,5 g of cresol red (3.3.7), and 45 g of potassium chloride (3.3.9). The given quantities can be reduced (e.g. by one tenth). 3.3.16 Carrier solution, C (see Figure A.1). Use water according to 3.3.1, degassed e.g. by reduced pressure. 3.3.17 Alkaline reaction solution, R1 (see F
45、igure A.1). Dissolve in a graduated flask, nominal capacity 1 000 ml, 30 g of ethylenedinitrilotetraacetic acid, disodium salt (3.3.4) in approximately 800 ml of water (3.3.1), and add 12,4 g of boric acid (3.3.10). Add 100 ml of sodium hydroxide solution I (3.3.2) dropwise to the suspension and mak
46、e up to volume with water (3.3.1). Degas the solution by filtering it through the membrane filter assembly (3.4.2). The pH of the solution will be approximately 13. Being stored in a plastics bottle (polyethene) at room temperature, it will be stable for one month. 3.3.18 Indicator solution. Dissolv
47、e in a 200 ml graduated flask 1 g of the mixed indicator (3.3.15) in a mixture of 50 ml of sodium hydroxide solution II (3.3.3). Make up to volume with water (3.3.1). The solution should have a dark reddish colour. Filter off any undissolved particles. This solution may be stored at room temperature
48、 for three months in an amber glass bottle. 3.3.19 Ammonia recipient solution, R2 (see Figure A.1). Dilute 10 ml of the indicator solution (3.3.18) with approximately 480 ml of water (3.3.1). The absorbance of the solution should be 0,3 to 0,5. Otherwise, add dropwise sodium hydroxide solution II (3
49、.3.3) or hydrochloric acid solution III (3.3.13) until an absorbance value of 0,3 to 0,5 (path length 10 mm, wavelength 590 nm) is obtained. Make up to 500 ml with water (3.3.1). Degas and purify the solution by the membrane filter assembly (3.4.2), fill it into the reagent reservoir and let it stand for at least 2 h. Immediately before starting the measurement (3.6), check the absorbance again and adjust, if need be, to the absorbance range specified above by adding sodium hydroxide s
