1、August 2015 Translation by DIN-Sprachendienst.English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS
2、 13.060.50!%Dky“2337286www.din.deDDIN ISO 22743Water quality Determination of sulfates Method by continuous flow analysis (CFA)(ISO 22743:2006 +Cor. 1:2007),English translation of DIN ISO 22743:2015-08Wasserbeschaffenheit Bestimmung von Sulfat Verfahren mittels kontinuierlicher Flieanalytik(CFA) (IS
3、O 22743:2006 + Cor. 1:2007),Englische bersetzung von DIN ISO 22743:2015-08Qualit de leau Dosage des sulfates Mthode par analyse en flux continu (CFA)(ISO 22743:2006 + Cor. 1:2007),Traduction anglaise de DIN ISO 22743:2015-08www.beuth.deDocument comprises 16 pagesIn case of doubt, the German-language
4、 original shall be considered authoritative.08.15 A comma is used as the decimal marker. Contents Page National foreword .3 National Annex NA (informative) Bibliography 5 Introduction .6 1 Scope 7 2 Normative references 7 3 Interferences 7 4 Principle 7 5 Reagents .8 6 Apparatus .9 7 Sampling and sa
5、mple pretreatment .10 8 Procedure .10 9 Calculation of results 12 10 Expression of results 12 11 Test report 13 Annex A (informative) Example of a CFA system for the determination of sulfate 14 Annex B (informative) Precision and accuracy 15 Bibliography 16 DIN ISO 22743:2015-08 2 National foreword
6、The text of this document (ISO 22743:2006 + Cor. 1:2007) has been prepared by Technical Committee ISO/TC 147 “Water quality” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the DIN-Normenausschuss Wasserwesen (DIN Standards Committee Water Practice), Working
7、Committee NA 119-01-03 AA Wasseraufbereitung. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. DIN shall not be held responsible for identifying any or all such patent rights. Designation of the method: Determination of sulfates Me
8、thod by continuous flow analysis (CFA) (D 44): Method DIN ISO 22743 D 44 As a result of national implementation in Germany, the following action has been taken: In this document, the symbol ( )24SO is used for sulfate ion, whereas the original ISO document uses the symbol SO4. The DIN Standards corr
9、esponding to the International Standards referred to in this document are as follows: ISO 3696 DIN ISO 3696 ISO 5667-3 DIN EN ISO 5667-3 ISO 8466-1 DIN 38402-51 ISO 8466-2 DIN ISO 8466-2 DIN ISO 22743:2015-08 3 Expert assistance and specialized laboratories will be required to perform the analyses d
10、escribed in this standard. Existing safety requirements are to be observed. Depending on the objective of the analysis, a check shall be made on a case-by-case basis as to whether and to what extent additional conditions will have to be specified. This standard has been prepared by the DIN-Normenaus
11、schuss Wasserwesen (DIN Standards Committee Water Practice) in collaboration with the Wasserchemische Gesellschaft Fachgruppe in der Gesellschaft Deutscher Chemiker (Water Chemistry Society Division of the German Chemical Society). It is part of the series Deutsche Einheitsverfahren zur Wasser-, Abw
12、asser- und Schlammuntersuchung (German standard methods for the examination of water, waste water and sludge): Determination of sulfates Method by continuous flow analysis (CFA) (D 44). Standard methods published as DIN Standards are obtainable from Beuth Verlag GmbH, either individually or grouped
13、in volumes. The standard methods included in the loose-leaf publication entitled Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung will continue to be published by Beuth Verlag GmbH and Wiley-VCH Verlag GmbH general information (group A) Calibration of analytical methods, eva
14、luation of analytical results and linear calibration functions used to determine the performance characteristics of analytical methods (A 51) DIN EN ISO 5667-3, Water quality Sampling Part 3: Preservation and handling of water samples DIN ISO 3696, Water for analytical laboratory use Specification a
15、nd test methods DIN ISO 8466-2, Water quality Calibration and evaluation of analytical methods and estimation of performance characteristics Part 2: Calibration strategy for non-linear second-order calibration functions DIN ISO 22743:2015-08 5 Introduction Methods using flow analysis automate wet ch
16、emical procedures and 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, 2or by continuous flow analysis (CFA) 3. Both methods share the feature of an automatic dosa
17、ge of the sample into a flow system (manifold) where the analytes in the sample react 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). The detector produce
18、s a signal from which the concentration of the parameter is calculated. It is necessary to examine whether and to what extent particular problems will require the specification of additional marginal conditions. In this International Standard, only the CFA procedure is described. Water quality Deter
19、mination of sulfates Method by continuous flow analysis (CFA) DIN ISO 22743:2015-08 6 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
20、 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 staff. 1 Scope This International
21、 Standard specifies a continuous flow analysis (CFA) method for the determination of sulfate in various types of water (such as ground water, drinking water and waste water). 100 mg/l to 1 000 mg/l). 2 Normative references The following referenced documents are indispensable for the application of t
22、his document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3696, Water for analytical laboratory use Specification and test methods ISO 5667-3, Water quality Sampling Part 3: Guidan
23、ce 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 the linear calibration function ISO 8466-2, Water quality Calibration and evaluation of anal
24、ytical methods and estimation of performance characteristics Part 2: Calibration strategy for non-linear second-order calibration functions 3 Interferences Calcium-, magnesium-, iron- and aluminium ions interfere with the determination of sulfate (negative bias). Treatment with a cation exchange res
25、in will reduce the interferences. Sulfide, sulfite, phosphate and tannic acids may lead to a positive bias, but concentrations of these substances which cause measurable interferences are usually not found in real samples. The method is applicable to samples with a sulfate (SO4)N*)mass concentration
26、 from 30 mg/l to 300 mg/l. Other concentration ranges are applicable, provided they cover exactly one decade of concentration units (e.g. 4 Principle Sulfate reacts in an acidic solution with barium chloride to form barium sulfate. The excessive barium chloride reacts with methylthymol blue in an al
27、kaline solution to a chelated barium methylthymol blue. The absorbance of the free non-chelated methylthymol blue is measured at 460 nm 10 nm in a flow through detector. Other N*) National footnote: See National foreword. DIN ISO 22743:2015-08 7 5 Reagents Use analytical grade chemicals, unless othe
28、rwise specified, and check the blank value of the reagents. 5.1 Water, complying with grade 1 as defined in ISO 3696. 5.2 Barium chloride dihydrate, BaCl22H2O. 5.3 Concentrated hydrochloric acid, c(HCl) = 12 mol/l, (HCl) = 1,19 g/ml. 5.4 Methylthymol blue, (C37H40N2O13SNa4or C37H43N2O13SNa). 5.5 Sur
29、factant, polyoxyethylene-23-laurylether (C12H25(OCH2CH2)23OH), a mass fraction of 30 % solution in water. 5.6 Sodium hydroxide, (NaOH). 5.7 Ethylenedinitrilotetracetic acid tetrasodium salt, Na4-EDTA, (C10H12N2Na4O8). 5.8 Ammonium chloride, (NH4Cl). 5.9 Ammonia solution, 25 % solution, c(NH3H2O) = 1
30、4 mol/l, (NH3H2O) = 0,91 g/ml. 5.10 Ethanol, C2H5OH, a volume fraction of 96 %, = 0,79 g/ml, food grade or pure grade. 5.11 Sodium sulfate, (Na2SO4), dried for 2 h at 105 C. 5.12 Cation exchange resin, DOWEX 50W-X81), particle size 0,3 mm to 0,8 mm in H+form. 5.13 Barium chloride solution In a 1 000
31、 ml volumetric flask, dissolve 917 mg 1 mg of barium chloride dihydrate (5.2) in about 500 ml of water (5.1) and make up to volume with water (5.1). When stored at 2 C to 6 C, the solution is stable for 1 month. 5.14 Diluted hydrochloric acid, c(HCl) = 1 mol/l. In a 1 000 ml volumetric flask, dilute
32、 82 ml of concentrated hydrochloric acid (5.3) in about 800 ml of water (5.1) and make up to volume with water (5.1). 5.15 Methylthymol blue solution In a 1 000 ml volumetric flask, dissolve 160 mg 1 mg of methylthymol blue (5.4) in 50 ml of barium chloride solution (5.13). Add 4 ml of diluted hydro
33、chloric acid (5.14) and 360 ml of ethanol (5.10). Make up to volume with water (5.1). Add 1 ml of surfactant (5.5). When stored at 2 C to 6 C, the solution is stable for 1 week. 1) DOWEX 50W-X8 is a trade name. This information is given for the convenience of users of this International Standard and
34、 does not constitute an endorsement by ISO of this product. metals, such as calcium, magnesium, iron and aluminium, are removed by an ion exchange column prior to the reactions with barium. DIN ISO 22743:2015-08 8 5.16 Buffered Na4-EDTA solution, pH = 10,5. In a 1 000 ml volumetric flask, dissolve 6
35、,75 g of ammonium chloride (5.8) and 40,0 g of Na4-EDTA (5.7) in about 500 ml of water (5.1). Add 57 ml of ammonia solution (5.9) and make up to volume with water (5.1). 5.17 Sodium hydroxide solution, c(NaOH) = 0,25 mol/l. In a 1 000 ml volumetric flask, dissolve 10,0 g of sodium hydroxide (5.6) in
36、 about 500 ml of water (5.1). Make up to volume with water (5.1). 5.18 Sulfate stock solution, (SO4) = 3 000 mg/l. In a 1 000 ml volumetric flask, dissolve (4 436 1) mg of sodium sulfate (5.11) in about 500 ml of water (5.1). Make up to volume with water (5.1). 5.19 Sulfate spiking solution, (SO4) =
37、 6 mg/l. In a 1 000 ml volumetric flask, dilute 2,00 ml of sulfate stock solution (5.18) in about 800 ml of water (5.1). Make up to volume with water (5.1). Add 1 ml of surfactant (5.5). NOTE The sulfate solution is added to achieve better linearity in the lower measuring part of the calibration cur
38、ve. In respect to the sulfate concentration in the blank or the quality of the methylthymol blue (5.4), the added sulfate amount can be slightly altered. Without the sulfate addition, this lower part will not be linear. 5.20 Calibration solutions Prepare at least five calibration solutions by diluti
39、ng the sulfate stock solution (5.18). Table 1 gives examples for the preparation of 10 calibration solutions in the range of 30 mg/l to 300 mg/l. Table 1 Example for preparation of 10 calibration solutions for the sulfate (SO4) range 30 mg/l to 300 mg/l Volume in ml of sulfate stock solution (5.18)
40、diluted to 100 ml 1 2 3 4 5 6 7 8 9 10 Sulfate (SO4) concentration of calibration solution in mg/l 30 60 90 120 150 180 210 240 270 300 6 Apparatus 6.1 Continuous-flow analysis (CFA). The system generally consists of the following components (see Figure A.1 in Annex A). 6.1.1 Sampler or other device
41、, for reproducible sample introduction. 6.1.2 Reagent containers. N*)N*) National footnote: See National foreword. DIN ISO 22743:2015-08 9 6.1.3 Low pulse pump, with chemical resistant pump tubes. 6.1.4 Inlet connector, made of glass, or chemical resistant material, with reproducible air-, sample- a
42、nd reagent segmentation. 6.1.5 Photometer, with flow cell, optical path length, e.g. 10 mm, wavelength range 450 nm to 470 nm. 6.1.6 Data acquisition and display unit, such as a PC, recorder, printer or plotter. 6.2 Graduated flasks, nominal capacity 100 ml and 1 000 ml. 6.3 Graduated pipettes, nomi
43、nal capacity 1 ml, 2 ml, 3 ml, 4 ml, 5 ml, 6 ml, 7 ml, 8 ml, 9 ml, 10 ml and 50 ml. 6.4 Cation exchange column. Glass tube with a length of at least 10 cm and an internal diameter of approximately 2 mm. Suspend the cation exchange resin in water (5.1) and fill the tube with this mixture. Close both
44、sides of the tube with approximately 5 mm of glass wool. 7 Sampling and sample pretreatment Carry out sampling as specified in ISO 5667-3. Prior to use rinse all containers which will come into contact with the sample with water (5.1). The samples may be stored in either glass or plastics containers
45、 for at least one month. Sample preservation is not required (see ISO 5667-3). Prior to analysis, filter the sample, if necessary. 8 Procedure 8.1 Preparation for the analyses Set up the flow analyser for the desired procedure (see Figure A.1 in Annex A). Pump hydrochloric acid (5.14) for 15 min to
46、regenerate the cation exchange column (6.4). Use the pump tube for the sulfate spiking solution (5.19). Rinse the column by pumping water (5.1) through the column for 10 min. Pump the reagents (see Figure A.1) for up to 15 min and set the baseline to zero. The analyser is operational when there is n
47、o baseline drift. Proceed in accordance with 8.2 to 8.5. 8.2 Quality requirements for the measuring system 8.2.1 Instrument performance checks The following requirements apply. a) In the analytical system, prepared according to 8.1, a calibration solution (5.20) with a sulfate concentration of about
48、 100 mg/l shall exhibit an absorbance per centimetre of at least 0,260 cm1. Otherwise, the flow system is not suitable, and it shall be replaced by a system which fulfill this requirement. DIN ISO 22743:2015-08 10 If the photometric detector (6.1.5) does not allow any absorbance readings, the absorbance may be determined by comparing an external absorbance measuring photometer. In this case, a sufficient quantity of the reaction mixture (containing the sample) and the appropriate reag
