1、16265:2012ICS 13.060.50NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISHSTANDARDWaterqualityDeterminationofthemethyleneblueactivesubstances(MBAS)indexMethodusingcontinuousflowanalysis(CFA)BS EN ISONational forewordThis British Standard is the UK implementation of EN ISO 1
2、6265:2012. It is identical to ISO 16265:2009. It supersedes BS ISO 16265:2009, which is withdrawn.The UK participation in its preparation was entrusted by Technical Committee EH/3, Water quality, to Subcommittee EH/3/2, Physical chemical and biochemical methods.A list of organizations represented on
3、 this subcommittee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.BS EN ISO 16265:2
4、012This British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 August2009 The British Standards Institution 2012. Published by BSI Standards Limited 2012.Amendments/corrigenda issued since publicationDate Comments 30 April 2012 This corrigendum renumbers
5、BS ISO 16265:2009 as BS EN ISO 16265:2012.ISBN 978 0 580 75430 2EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 16265 February 2012 ICS 13.060.50 English Version Water quality - Determination of the methylene blue active substances (MBAS) index - Method using continuous flow analysis (CFA)
6、(ISO 16265:2009) Qualit de leau - Mesurage de lindice des substances actives au bleu de mthylne (SABM) - Mthode par analyse en flux continu (CFA) (ISO 16265:2009) Wasserbeschaffenheit - Bestimmung des Indexes von methylenblauaktiven Substanzen (MBAS) - Verfahren mittels kontinuierlicher Durchflussan
7、alyse (CFA) (ISO 16265:2009) This European Standard was approved by CEN on 15 January 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date
8、lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation un
9、der the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France
10、, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMI
11、TEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 16265:2012: EForeword The text of ISO 16265:2009 has been prepared by Technical Committee ISO/TC 147 “Wate
12、r quality” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 16265:2012 by Technical Committee CEN/TC 230 “Water analysis” the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publicati
13、on of an identical text or by endorsement, at the latest by August 2012, and conflicting national standards shall be withdrawn at the latest by August 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall
14、not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmar
15、k, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 16265:2009 has been
16、approved by CEN as a EN ISO 16265:2012 without any modification. BS EN ISO 16265:2012 EN ISO 16265:2012 (E)ii ISO 2012Contents PageForeword viIntroduction.vii1Scope. 12Normative references. 13Interferences . 14Principle. 25Reagents26Apparatus 47Sampling and sample pretreatment58Procedure 59Calculati
17、on of the results. 710 Expression of results. 811 Precision 812 Test report.8Annex A (informative) Example of a flow diagram for the determination of MBAS index bycontinuous flow analysis (CFA) 9Annex B (informative) Precision data. 10Bibliography. 11BS EN ISO 16265:2012 EN ISO 16265:2012 (E) ISO 20
18、12 iiiForeword ISO (the International Organization 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 whi
19、ch a tec hnical committee has beenestablished 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 closelywith the International Electrotechnical Commission (IEC) on all ma
20、tters of electrotechnical standardization. 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 Standardsadopted by the technical committees are circul
21、ated to the member bodies for voting. Publication 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 responsib
22、le for identifying any or all such patent rights. ISO 16265 was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2, Physical,chemical and biochemical methods. BS EN ISO 16265:2012 EN ISO 16265:2012 (E) ISO 2012iv Introduction Methodsusing flow analysis automate wet chemical
23、 procedures and are particularly suitable for the processing of many analytes in water in large numbers of samples at a high analysis frequency (up to 100 samples per hour).A differentiation is made between flow injection analysis (FIA) 1, 2 and continuous flow analysis (CFA) 3. Both methods share t
24、he feature of an automatic dosa ge of the sample into a flow system (manifold) where theanalytes in the sample react with the reagent solutions on their waythrough the manifold. The samplepreparation maybe integrated in the manifold. The reaction product is measured in a flow detector (e.g. a photom
25、eter). The detector produces a signal from which the concentration of the parameter is calculated. The MBAS (methylene blue active substances)index is an analytical convention (a method-definedparameter) used for water quality control purposes. It measures surfactants and other substances that react
26、with methylene blue under specified conditions. The user should be aware that particular problems could require the specification of additional conditions. BS EN ISO 16265:2012 EN ISO 16265:2012 (E)v ISO 2012 INTERNATIONAL STANDA RD 1Water quality Determination of the methylene blue activesubstances
27、 (MBAS) index Method using continuous flowanalysis (CFA)WARNING Persons using this International Standard should be familiar with normal laboratorypractice. This standard does not p urport to address all of the safety problems, if any, associated withits use. It is the responsibility of the user to
28、establish appropriate safetyand health practices and toensure compliance with any national regulatory conditions. IMPORTANT It is absolutely essential that tests conducted in accordance with this InternationalStandard be carried out by suitably trained staff.Trichloromethane and methanol waste solut
29、ions should be disposed of properly. 1 Scope This International Standard specifies a procedure for the determination of the methylene b lue activesubstances (MBAS)index, in the ranges 0,05mg/l to 0,5 mg/l and 0,5 mg/l to 5,0 mg/l, invarious watersamples (e.g. ground water, drinking water,surface wat
30、er, waste water and leachates). Anionic surfactantsare the most important substances showing methylene blue activity. This method is therefore useful forestimating the anionic surfactant content including anionic surfactants with carboxylate groups (e.g. soaps) ofwater. Other types of substance maya
31、lso show methylene blue activityand contribute to the result. On a case-by-case basis, the range of the analysis may be changed and the method used for other concentrationranges provided they cover exactly one decade of concentration units.2 NormativereferencesThe following referenced documents are
32、indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the latestedition of the reference document(including anyamendments) applies.ISO 648, Laboratory glassware Single-volume pipettesISO 1042, Laboratory glassware One-mark vo
33、lumetric flasksISO 3696, Water for analytical laboratory use Specification and test methods3 Interferences The following substances can interfere with the analysis: Cationic compounds able to form strong ion-pairswith the active substances in methylene blue. Humic acids in concentrations 20 mg/l. Ch
34、emicals with a high surface activity (e.g. non methylene blue active surfactants in concentrations 50 mg/l).EN ISO 16265:2012 (E)BS EN ISO 16265:2012 ISO 20122 Chemicals with a strong reductive potential for the oxidation of methylene blue (e.g. S 2 , 23SO , 223SO ,OCl ). These chemicals shall be re
35、moved (e.g. with H2 O 2 ) prior to analysis. High concentrations of inorganic anions (e.g. nitrate, chloride, bromide) may cause positive bias. Chemicals which reactwith anyof the reagents used to form a coloured compound soluble in trichloromethane (CHCl 3 ) (excluded are methylene blue active subs
36、tances).Filtration of the sample before analysis is advisable for samples containingparticles larger than 100 m in size. Otherwise the particles in the sample may clog the transport tubes. If filtration isnecessary, significant losses of anionic surfactants due to adsorbance effects are possible.The
37、 absorbance due to the colour of the sample can be compensated for by a blank analysis which omits the methylene blue from the reagents. The responses of the sample with and without reagent addition are determined. The difference between the two responses is used in Equations (3) and (4).Samples wit
38、h an MBAS index concentration 5 mg/l shall be diluted before analysis. 4 Principle The sample is mixed, in a continuously flowing stream, with an alkaline methylene blue solution, formingcoloured ion-pairs with certain types of organic substance (e.g. anionic surfactants) contained in the sample. Th
39、e ion-pairs are extracted with trichloromethane. The organic phase is treated with an acidic methylene bluesolution and its absorbance determined photometricallyat a wavelength of 650 nm 10 nm. The result is expressed in terms of sodium dodecyl sulfate concentration. 5 ReagentsUnless otherwise state
40、d, use only reagents of recognized analytical grade. Degas reagents if air bubbles appear spontaneously. Unless otherwise specified, degas bypassing heliumgas at 20 l/h through the reagent for 15 min. Add detergent after degassing. Avoid using reagents showing anyturbidity, filtering them if necessa
41、ry. 5.1 Water, complying with grade 1 as defined in ISO 3696.5.2 Sodium hydroxide, NaOH. 5.3 Sodium tetraborate decahydrate, Na2 B 4 O 7 10H2 O.5.4Sodium dihydrogen phosphate monohydrate, NaH 2 PO4 H2 O. 5.5 Potassium dihydrogen phosphate monohydrate , KH 2 PO4 H2 O. 5.6 Sulfuric acid, H 2 SO4 , (H2
42、 SO4 ) = 1,84 g/ml. 5.7 Hydrochloricacid , HCl, (HCl) = 1,18 g/ml. 5.8 Methylene blue , C 16H 18N 3 SCl2H2 O. 5.9 Methanol, CH3 OH. 5.10 Ethanol , C2 H 5 OH, w (C2 H 5 OH) 96 %.5.11 Trichloromethane , CHCl3 . Trichloromethane is stable for 3 months if stored in a dark place. BS EN ISO 16265:2012 EN
43、ISO 16265:2012 (E) ISO 20123Before use, degas the trichloromethane for 30 min by purgingwith a stream of He or by using an ultrasonic bath. 5.12 Sodium dodecyl sulfate (sodium lauryl sulfate), CH3 (CH 2 ) 11OSO 3 Na. 5.13 Petroleum ether . 5.14 Poly(ethylene glycol) dodecyl ether , HO(CH2 CH2 O)n C
44、12H 25, aqueous solution, w = 30 %.5.15 Alkaline borate solution. Dissolve 15,83 g of sodium tetraborate decahydrate (5.3) and 3,3 g ofsodium hydroxide (5.2) inapproximately 800 ml of water (5.1) and make up to 1 000 ml with water (5.1) in a volumetric flask (6.2.1).This solution is stable for one w
45、eek if stored at room temperature. 5.16 Stock methylene blue solution. Dissolve 0,35g of methylene blue in 500 ml of ethanol (5.10) and make up to 1 000 ml withwater (5.1) inavolumetric flask (6.2.1). This solution is stable for 6 months if stored at room temperature. 5.17 Alkaline methylene blue so
46、lution. Add 100 ml of stock methylene blue solution (5.16) to50 ml of alkaline borate solution (5.15) and mix.Washthis mixture three times with 20 ml of trichloromethane (5.11) until the organic layer is no longer blue,removing the organic layer each time. Extract the aqueous solution thus obtained
47、with 25ml of petroleumether (5.13) to remove the trichloromethane remaining in the solution. Filter through a paper filter (porewidth 0,45 m) and make up to 500 ml with water (5.1) in a volumetric flask (6.2.1).Prepare this solution freshlybefore use. 5.18 Acidified methylene bluesolution. Add 6,8 m
48、l of sulfuric acid (5.6) to 42,5 ml of stock methylene blue solution (5.16). Dissolve in this mixture50 g of sodium dihydrogen phosphate monohydrate (5.4). Make up to a volume of 1 000 ml withwater (5.1) in a volumetric flask (6.2.1). This solution is stable for one week if stored at room temperatur
49、e. 5.19 Trichloromethane extraction solution (CHCl3 in Figure A.1). Add 1 ml of poly(ethene glycol) dodecyl ether (5.14) to 1 000 ml of trichloromethane (5.11) and mix.This solution is stable for one week if stored at room temperature. 5.20 Rinsing solution for the sampler . Dissolve 1,1 g of potassium dihydrogen phosphate monohydrate (5.5) in approximately 800 ml of water (5.1) and make up to 1 000 ml with water (5.1) in a volumetric
