1、BS EN ISO 23913:2009ICS 13.060.50NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDWater quality Determination of Chromium(VI) Method using flow analysis (FIA and CFA) and spectrometric detection (ISO 23913:2006)This British Standard was published under the author
2、ity of the Standards Policy and Strategy Committee on 31October 2009. BSI 2009ISBN 978 0 580 68104 2Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 23913:2009National forewordThis British Standard is the UK implementation of EN ISO 23913:2009. It is identical to ISO 23913:2006.T
3、he UK participation in its preparation was entrusted to TechnicalCommittee EH/3/2, Physical chemical and biochemical methods.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a
4、contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 23913May 2009ICS 13.060.50English VersionWater quality - Determination of chromium(VI) - Method usingflow
5、 analysis (FIA and CFA) and spectrometric detection (ISO23913:2006)Qualit de leau - Dosage du chrome(VI) - Mthode paranalyse en flux (FIA et CFA) et dtection spectromtrique(ISO 23913:2006)Wasserbeschaffenheit - Bestimmung von Chrom(VI) -Verfahren mittels Flieanalytik (FIA und CFA) undspektrometrisch
6、er Detektion (ISO 23913:2006)This European Standard was approved by CEN on 14 May 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists
7、and bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsib
8、ility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland,
9、Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17
10、, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 23913:2009: EEN ISO 23913:2009 (E) 3 Foreword The text of ISO 23913:2006 has been prepared by Technical Committee ISO/TC 147 “Water quality” of the Internatio
11、nal Organization for Standardization (ISO) and has been taken over as EN ISO 23913:2009 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 publication of an identical text or b
12、y endorsement, at the latest by November 2009, and conflicting national standards shall be withdrawn at the latest by November 2009. 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 not be held responsible
13、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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germ
14、any, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 23913:2006 has been approved by CEN as a EN ISO 23913:2009 wi
15、thout any modification. BS EN ISO 23913:2009ISO 23913:2006(E) ISO 2006 All rights reserved iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Principle. 1 4 Interferences . 2 5 Reagents 2 6 Apparatus 5 7 Sampling and sample preparation 6 8 Procedure 6 9 Determinatio
16、n 7 10 Expression of results . 8 11 Test report . 8 Annex A (informative) Examples of flow analysis systems for the determination of chromium(VI). 9 Annex B (informative) Performance characteristics. 12 Bibliography . 14 BS EN ISO 23913:2009ISO 23913:2006(E) iv ISO 2006 All rights reservedForeword I
17、SO (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 which a technical c
18、ommittee has been established 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 electr
19、otechnical 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 Standards adopted by the technical committees are circulated to the m
20、ember 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 responsible for identi
21、fying any or all such patent rights. ISO 23913 was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2, Physical, chemical and biochemical methods. BS EN ISO 23913:2009ISO 23913:2006(E) ISO 2006 All rights reserved vIntroduction Methods using flow analysis automatic wet chem
22、ical procedures are particularly suitable for the processing of many analytes in water, in large sample series at a high analysis frequency. Analysis can be performed by flow injection analysis (FIA)1, 2and continuous flow analysis (CFA). Both methods share the feature of an automatic dosage of the
23、sample into a flow system (manifold) where the analyte in the sample reacts with the reagent solutions on its way through the manifold. The sample preparation may be integrated in the manifold. The reaction product is measured in a flow detector (e.g. flow photometer). It should be investigated whet
24、her and to what extent particular problems will require the specification of additional marginal conditions. BS EN ISO 23913:2009This page deliberately left blankINTERNATIONAL STANDARD ISO 23913:2006(E) ISO 2006 All rights reserved 1Water quality Determination of chromium(VI) Method using flow analy
25、sis (FIA and CFA) and spectrometric detection WARNING Persons using this International Standard should be familiar with normal laboratory practice. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish
26、 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 International Standard are carried out by suitably qualified staff. 1 Scope This International Standard specifies flo
27、w injection analysis (FIA) and continuous flow analysis (CFA) methods for the determination of chromium(VI) in various types of water. The method applies to the following mass concentration ranges. FIA: 20 g/l to 200 g/l and 200 g/l to 2 000 g/l for surface water, leachates and waste water. CFA: 2 g
28、/l to 20 g/l and 20 g/l to 200 g/l for drinking water, ground water, surface water, leachates and waste water. The range of application may be changed by varying the operating conditions. Seawater may be analysed by these methods with changes in sensitivity and after adaptation of the reagent and ca
29、libration solutions to the salinity of the samples. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including
30、 any amendments) applies. ISO 3696, Water for analytical laboratory use Specification and test methods 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 pe
31、rformance characteristics Part 1: Statistical evaluation of the linear calibration function 3 Principle Chromium(VI) reacts with 1,5-diphenylcarbazide (DPC) to form a red-violet chromium-1,5-diphenylcarbazone complex. The absorbance of this complex is measured at 544 nm 10 nm (maximum absorbance at
32、544 nm). BS EN ISO 23913:2009ISO 23913:2006(E) 2 ISO 2006 All rights reserved4 Interferences Reducing agents in the sample may lead to negative bias for the chromium(VI) concentration. Nitrite does not interfere with the method under the reaction conditions. Concentrations of sulfide exceeding 0,2 m
33、g/l interfere with the method. Oxidizing agents for disinfection in drinking water production like chlorine, chlorine dioxide, ozone and hydrogen peroxide do not interfere with the method provided their mass concentration does not exceed the concentrations given in Table 1. Table 1 Mass concentratio
34、ns of single disinfection agents not producing significant interference under the given measuring conditions Concentration Disinfectant mg/l Chlorine 0,6 Chlorine dioxide 0,4 Hydrogen peroxide 0,2 Ozone 0,1 Other oxidizing agents like peroxoacetic acid, or permanganate may interfere in the chromium(
35、VI) determination. This shall be considered in the results. Strongly alkaline or buffered samples may cause negative bias. This effect may be tested by adding 1 part of acid mixture (5.5.1 or 5.5.2) to 3 parts of the sample. This mixture shall have a pH of 1. Otherwise, pretreat the samples with aci
36、ds (HCl, H2SO4) until the above mentioned test leads to sufficient results. Iron (III) ions exceeding 10 mg/l interfere with the methods. In the range of 10 mg/l to 100 mg/l, iron (III) ions may lead to a negative bias of up to 8 %. Coloured or turbid samples can cause a bias. To avoid bias, measure
37、 the sample again using solution 5.17 instead of solution 5.10 for feeding line “R2” in Figures A.1 to A.3. Subtract the result of this measurement ysfrom the term y in Equation (2). 5 Reagents Use analytical grade chemicals unless otherwise specified. 5.1 Water, complying to grade 1 as defined in I
38、SO 3696. The chromium blank value shall be checked (see 8.3). 5.2 Sulfuric acid, (H2SO4 ) = 1,84 g/ml. 5.3 Orthophosphoric acid, (H3PO4) = 1,71 g/ml. 5.4 Surfactant solution, aqueous polyethylene glycol dodecyl ether, HO-(CH2-CH2O)nC12H21, with a mass fraction of 30 %. BS EN ISO 23913:2009ISO 23913:
39、2006(E) ISO 2006 All rights reserved 35.5 Acid mixtures. 5.5.1 Acid mixture for FIA, (R1 in Figure A.1). Add to a 250 ml volumetric flask about 125 ml of water (5.1). Add 29 ml of sulfuric acid (5.2) and 31 ml of orthophosphoric acid (5.3), mix and bring to volume with water (5.1). This solution aci
40、difies the reaction mixture passing the detector to a necessary pH of 1. The solution is stable for up to 1 year if stored at room temperature. 5.5.2 Acid mixture for CFA, (R1 in Figures A.2 and A.3). Add 1 ml of surfactant solution (5.4) to 200 ml of acid mixture for FIA (5.5.1). The solution is st
41、able for up to 1 week if stored at room temperature. 5.6 1,5-diphenylcarbazide, C13H14N4O. 5.7 Acetone, C3H6O. 5.8 1-Propanol, C3H8O. 5.9 Potassium dichromate, K2Cr2O7. 5.10 Diphenylcarbazide solution, (R2 in Figures A.1 to A.3). Dissolve in a 250 ml beaker 0,43 g of 1,5-diphenylcarbazide (5.6) in 9
42、 ml of acetone (5.7) and 9 ml of 1-propanol (5.8). Add 125 ml of 1-propanol (5.8).Transfer the mixture to a 250 ml volumetric flask, and make up to volume with water (5.1). The solution is stable for up to 1 week if stored in a brown glass bottle at 2 C to 6 C. If precipitation occurs, filter the so
43、lution. NOTE The use of a mixture of acetone and 1-propanol permits the redissolving of precipitates of 1,5-diphenylcarbazide occurring on cooling. In the literature, several solvents (acetone, 1-propanol, 2-propanol, ethanol, in combination with water) are proposed for preparing the diphenylcarbazi
44、de solution. These alternatives are also applicable, provided the solutions are stable enough and contain the same concentration of 1,5-diphenylcarbazide (5.6) as given in 5.10. Degas carefully all reagent solutions for the FIA determinations before use, e.g. by vacuum filtration. 5.11 Carrier solut
45、ion for FIA systems, (C in Figure A.1). Use water (5.1). Carrier and samples should have identical acidity. For unpreserved samples, this means that water should be used as a carrier. According to References 5 and 6 in the Bibliography, acidic preservation should be avoided in chromium speciation be
46、cause of low recovery. 5.12 Chromium(VI) stock solution, Cr(VI) = 1 000 mg/l. WARNING Potassium dichromate is carcinogenic. Dissolve 2,829 g of potassium dichromate, K2Cr2O7(5.9) in water (5.1) in a 1 000 ml volumetric flask. Dilute to volume with water (5.1). The solution is stable for up to 1 year
47、 if stored at room temperature. 1 ml of this solution contains 1 mg of Cr(VI). NOTE Chromium(VI) solutions are commercially available and may be used in this International Standard. BS EN ISO 23913:2009ISO 23913:2006(E) 4 ISO 2006 All rights reserved5.13 Chromium(VI) standard solution I, Cr(VI) = 10
48、 mg/l. Pipette 1 ml of the chromium(VI) stock solution (5.12), into a 100 ml volumetric flask. Dilute to volume with water (5.1). Prepare this solution fresh daily. The solution can be stored during the day of use at room temperature. 1 ml of this solution contains 10 g of Cr. 5.14 Chromium(VI) stan
49、dard solution II, Cr(VI) = 1 mg/l. Pipette 10 ml of the chromium(VI) standard solution I (5.13), into a 100 ml volumetric flask. Dilute to volume with water (5.1). Prepare this solution fresh daily. The solution can be stored during the day of use at room temperature. 1 ml of this solution contains 1 g of Cr. 5.15 Chromium(VI) standard solution III, Cr(VI) = 0,1 mg/l. Pipette 10 ml of the chromium(VI) standard solution II (5.14), into a 100 ml volumetric flask. Dilute to volume w
