1、BRITISH STANDARD BS EN ISO 11905-1:1998 BS6068-2.62: 1998 Water quality Determination of nitrogen Part1: Method using oxidative digestion with peroxodisulfate The European Standard EN ISO11905-1:1998 has the status of a British Standard ICS13.060.01BSENISO11905-1:1998 This British Standard, having b
2、een prepared under the directionof the Health and Environment Sector Board,was published under theauthority of the Standards Board and comes into effect on 15 July 1998 BSI 04-1999 ISBN 0 580 29952 X Amendments issued since publication Amd. No. Date CommentsBSEN ISO11905-1:1998 BSI 04-1999 i Content
3、s Page National foreword ii Foreword 2 Foreword iii Text of ISO11905-1 1BSENISO11905-1:1998 ii BSI 04-1999 National foreword This British Standard is the English language version of EN ISO11905-1:1998. It is identical with ISO11905-1:1997. The UK participation in its preparation was entrusted by Tec
4、hnical Committee EH/3, Water quality, to Subcommittee EH/3/2, Physical, chemical and biochemical methods, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, a
5、nd keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standar
6、ds normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “Inter
7、national Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. BS EN ISO11905-1 is one of a series of standards on water quality, others of which have been, or will be, published as sections of BS6068. This standard has therefore been given the s
8、econdary identifier BS6068-2.62. The various sections of BS6068 are comprised within Parts1to7, which, together with Part0, are listed below. Part0: Introduction; Part1: Glossary; Part2: Physical, chemical and biochemical methods; Part3: Radiological methods; Part4: Microbiological methods; Part5: B
9、iological methods; Part6: Sampling; Part7: Precision and accuracy. NOTEThe tests described in this British Standard should only be carried out by suitably qualified persons with an appropriate level of chemical expertise. Standard chemical procedures should be followed throughout. A British Standard
10、 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 immunity from legal obligations. Summary of pages This document comprises a front cover, an
11、inside front cover, pagesi andii, theEN ISOtitle page, page2, the ISO title page, pagesii toiv, pages1 to10, andaback cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.EUROPEAN S
12、TANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO11905-1 May 1998 ICS13.060.01 Descriptors: See ISO document English version Water quality Determination of nitrogen Part1:Method using oxidative digestion with peroxodisulfate (ISO11905-1:1997) Qualit de leau Dosage de lazote Partie1: Mthode par minralis
13、ation oxydante au peroxodisulfate (ISO11905-1:1997) Wasserbeschaffenheit Bestimmung von Stickstoff Teil1: Bestimmung von Stickstoff nach oxidativem Aufschlu mit Peroxodisulfat (ISO11905-1:1997) This European Standard was approved by CEN on 25 April 1998. CEN members are bound to comply with the CEN/
14、CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to a
15、ny CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions.
16、CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de
17、Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO11905-1:1998EENISO11905-1:1998 BSI 04-1999 2 Foreword The text of the Inte
18、rnational Standard from Technical Committee ISO/TC147 “Water quality” of the International Organization for Standardization (ISO) has been taken over as an European Standard by Technical Committee CEN/TC230 “Water analysis”, the secretariat of which is held by DIN. This European Standard shall be gi
19、ven the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 1998, and conflicting national standards shall be withdrawn at the latest by November 1998. According to the CEN/CENELEC Internal Regulations, the national standards organiz
20、ations of the following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The t
21、ext of the International Standard ISO11905-1:1997 has been approved by CEN as a European Standard without any modification. NOTENormative references to International Standards are listed in Annex ZA (normative).ENISO11905-1:1998 ii Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative refe
22、rences 1 3 Range of detection 1 4 Sensitivity 1 5 Principle 1 6 Reagents 2 7 Apparatus 3 8 Sampling and samples 3 9 Procedure 4 9.1 Test portion 4 9.2 Blank test 4 9.3 Cleaning digestion vessels 4 9.4 Digestion 4 9.5 Verification of recovery of organic nitrogen 4 9.6 Starting operation 4 9.7 Initial
23、 sensitivity setting 5 9.8 Calibration 5 9.9 Determination 6 10 Expression of results 6 10.1 Method of calculation 6 10.2 Precision data 6 11 Test report 6 Annex A (informative) Precision data 7 Annex B (informative) Recovery data for some nitrogen-containing compounds 8 Annex C (informative) Determ
24、ination of nitrate 9 Annex D (informative) Bibliography 10 Annex ZA (normative) Normative references to international publicationswiththeir relevant European publications 10 Figure 1 5 Table A.1 Precision data of the results of the total nitrogen internationalcollaborative trial 7 Descriptors: Water
25、, quality, water pollution, water tests, chemical analysis, determination of content, nitrogen, oxidation analysis.ENISO11905-1:1998 BSI 04-1999 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work
26、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 established has the right to be represented on that committee. International organizations, governmental and non-government
27、al, 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. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
28、 Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO11905-1 was prepared by Technical Committee ISO/TC147, Water quality, Subcommittee SC2, Physical, chemical and biochemical methods. ISO11905 consists of the follo
29、wing parts, under the general title Water quality Determination of nitrogen: Part1: Method using oxidative digestion with peroxodisulfate; Part2: Determination of bound nitrogen after oxidation and combustion to nitrogen dioxide using chemiluminescent detection. Annex A to Annex D of this part of IS
30、O11905 are for information only.iv blankENISO11905-1:1998 BSI 04-1999 1 Introduction This part of ISO11905 describes the peroxodisulfate oxidation of nitrogen compounds in water to produce nitrate. Specific details of the determination of a continuous flow method with initial reduction of nitrate to
31、 nitrite by copperized cadmium are then reported. The procedures referred to in the normativemethod is the reference method. Annex C gives examples of alternative techniques suitable for the determination of nitrate in the digest solution. While staying within the scope of this part of ISO11905, it
32、is permissible to use such alternatives only provided that their performance meets or is better than that given inTable A.1, when calculated using procedures described in ISO5725-2, and when the comparison of precision data between this part of ISO11905 and any alternative technique is carried out u
33、sing the procedures described in ISO2854. All references to nitrogen concentrations are expressed in milligrams of nitrogen per litre of solution (mg/l). 1 Scope This part of ISO11905 specifies a method for the determination of nitrogen present in water, in the form of free ammonia, ammonium, nitrit
34、e, nitrate and organic nitrogen compounds capable of conversion to nitrate under the oxidative conditions described. Dissolved nitrogen gas is not determined by this method. This method is applicable to the analysis of natural fresh water, sea water, drinking water, surface water and treated sewage
35、effluent. It is also applicable to the analysis of sewage and trade wastes in which the amount of organic matter in the test portion can be kept below40mg/l, expressed as carbon (C), when measured by Total Organic Carbon (TOC), or120mg/l, expressed as oxygen(O 2 ), when measured by Chemical OxygenDe
36、mand (COD) according to the respective International Standards. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO11905. At the time of publication, the editions indicated were valid. All standards are su
37、bject to revision, and parties to agreements based on this part of ISO11905 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of current valid International Standards. ISO3696:1987, Water for
38、 analytical laboratory use Specification and test methods. ISO5725-2:1994, Accuracy (trueness and precision) of measurement methods and results Part2:Basic methods for the determination of repeatability and reproducibility of a standard measurement method. 3 Range of detection Using the maximum test
39、 portion specified in9.1, nitrogen (N) can be determined in the range up to5mg/l. Much higher concentrations can be determined using smaller test portions. Using the maximum test portion, the lower limit of detection, expressed as N, is typically0,02mg/l. This depends on the method used to measure t
40、he nitrate concentration resulting from the oxidation. 4 Sensitivity Sensitivity will depend upon the method used to measure the nitrate concentration resulting from the oxidation. The main potential interference effects arise from dissolved or suspended organic matter present in samples, which comp
41、ete for the oxidation capacity of the peroxodisulfate reagent. To guarantee a sufficient excess of the oxidation reagent, if the COD of the original sample exceeds120mg/l, expressed asO 2 , or the TOC exceeds40mg/l, expressed as C, the sample needs to be diluted. Not all organic nitrogen compounds a
42、re quantitatively converted to nitrate by the oxidation. Poor recoveries can occur with compounds containing double- and triple-bonded nitrogen atoms and also with those substances containing aC=NH group. Compounds with free amino groups give less than quantitative recovery, but in no case less than
43、87%; good recoveries of nitrogen are reported for several heterocyclic compounds, see Annex B. Overall, the method gives good recovery performance for organic nitrogen compounds and gives results not significantly different from those obtained by instrumental, high temperature oxidation or reduction
44、 systems on a wide range of real samples containing significant amounts of organic matter. 5 Principle Ammonia, nitrite and many organic nitrogen-containing compounds in the test sample are oxidized to nitrate using peroxodisulfate in a buffered alkaline system by boiling at elevated pressure in a c
45、losed container.ENISO11905-1:1998 2 BSI 04-1999 Subsequent reduction of nitrate to nitrite is carried out by passage of the digest through a mixing coil containing copperized cadmium. The resulting nitrite is reacted with4-aminobenzene sulfonamide and N-(1-naphthyl)-1,2-diaminoethane dihydrochloride
46、 to produce a pink colour. Photometric measurement is carried out at540nm. 6 Reagents During the analysis, use water of purity grade3 as specified in ISO3696 and reagents of recognized analytical grade. 6.1 Sulfuric acid, c(H 2 SO 4 ) 4mol/l. Carefully mix(110 0,5) ml of concentrated sulfuric acid (
47、H 2 SO 4 , =1,84g/ml) into about350ml of water. Allow to cool to room temperature and dilute with water to(50010)ml. Store in a glass or plastics container. This reagent is stable indefinitely. WARNING:This reagent can cause severe burns. Wear gloves and eye protection when handling or preparing the
48、 acid. 6.2 Sodium hydroxide solution, c(NaOH) 0,375mol/l. Dissolve(15,0 0,5)g of sodium hydroxide in about900ml of water. Allow to cool to room temperature and make up to(1000 10)ml with water. Store in a polyethylene container. This reagent is stable for at least6months. WARNING:This reagent is cor
49、rosive. Wear gloves and eye protection when handling or preparing the solution. 6.3 Oxidizing solution. Dissolve(5,0 0,1)g of analytical reagent grade potassium peroxodisulfate (K 2 S 2 O 8 ), containing not more than0,001%(m/m) nitrogen as impurity, and(3,00 0,05)g of boric acid (H 3 BO 3 ) in(100 5)ml of sodium hydroxide solution(6.2). Store the solution in a polyethylene container in the dark at room temperature. This reagent is stable for up to one week. WARNING:This reagent is corrosive. Wear gloves a
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