SIST EN 14664:2005
(Main)Chemicals used for treatment of water intended for human consumption - Iron (III) sulfate, solid
Chemicals used for treatment of water intended for human consumption - Iron (III) sulfate, solid
This document is applicable to iron (III) sulfate solid used for treatment of water intended for human consumption. It describes the characteristics of iron (III) sulfate solid and specifies the requirements and the corresponding analytical methods for iron (III) sulfate solid (analytical methods are given in Annex C) and gives information on its use in water treatment. It also determines the rules relating to safe handling and use of iron (III) sulfate solid (see Annex B).
Produkte zur Aufbereitung von Wasser für den meschlichen Gebrauch - Eisen(III)sulfat, fest
Diese Europäische Norm gilt für Eisen(III)sulfatnonahydrat zur Aufbereitung von Wasser für den menschlichen Gebrauch. Sie beschreibt die Eigenschaften von Eisen(III)sulfatnonahydrat und legt die Anforderungen sowie die entsprechenden Prüfverfahren für Eisen(III)sulfatnonahydrat fest. Sie gibt Informationen für die Anwendung von Eisen(III)sulfatnonahydrat in der Wasseraufbereitung.
ANMERKUNG Eine Übereinstimmung mit dieser Norm bedeutet keine gleichzeitige Annahme oder Zulassung des Produktes in einem der Mitgliedsländer der EU oder EFTA. Die Anwendung des in dieser Europäischen Norm beschriebenen Produktes unterliegt den jeweiligen Regelungen der nationalen autorisierten Stellen.
Produits chimiques utilisés pour le traitement de l'eau destinée a la consommation humaine - Sulfate de fer (III) solide
Le présent document s'applique au sulfate de fer (III), solide utilisé pour le traitement de l'eau destinée a la consommation humaine. Il décrit les caractéristiques du sulfate de fer (III), solide et spécifie les exigences et les méthodes d'analyses correspondantes pour le sulfate de fer (III), solide ( les méthodes d'analyses sont données en annexes C) et donne des informations pour son emploi dans le traitement de l'eau. Il fixe également les regles relatives a la sécurité d'emploi et de manipulation du sulfate de fer (III), solide (voir annexe B).
Kemikalije, ki se uporabljajo za pripravo pitne vode – Železov (III) sulfat, v trdnem stanju
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kemikalije, ki se uporabljajo za pripravo pitne vode – Železov (III) sulfat, v trdnem stanjuProdukte zur Aufbereitung von Wasser für den meschlichen Gebrauch - Eisen(III)sulfat, festProduits chimiques utilisés pour le traitement de l'eau destinée a la consommation humaine - Sulfate de fer (III) solideChemicals used for treatment of water intended for human consumption - Iron (III) sulfate, solid71.100.80Chemicals for purification of water13.060.20Pitna vodaDrinking waterICS:Ta slovenski standard je istoveten z:EN 14664:2004SIST EN 14664:2005en01-marec-2005SIST EN 14664:2005SLOVENSKI
STANDARD
SIST EN 14664:2005
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 14664November 2004ICSEnglish versionChemicals used for treatment of water intended for humanconsumption - Iron (III) sulfate, solidProduits chimiques utilisés pour le traitment de l'eaudestinée à la consommation humaine - Sulfate de fer (III)solideProdukte zur Aufbereitung von Wasser für den meschlichenGebrauch - Eisen(III)sulfat, festThis European Standard was approved by CEN on 30 September 2004.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 and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat 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 responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2004 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14664:2004: ESIST EN 14664:2005
EN 14664:2004 (E) 2 Contents Page Foreword.3 1 Scope.5 2 Normative references.5 3 Description.5 4 Purity criteria.7 5 Test methods.8 6 Labelling - Transportation - Storage.10 Annex A (informative)
General information on iron (III) sulfate solid.13 Annex B (normative)
General rules relating to safety.18 Annex C (normative)
Analytical methods.19 Annex D (informative)
Reduction of Fe (III) on a silver column.35 Annex E (informative)
Determination of cadmium, chromium, nickel and lead (inductively coupled plasma optical emission spectrometry (ICP/OES)).37 Bibliography.39
SIST EN 14664:2005
EN 14664:2004 (E) 3 Foreword This document (EN 14664:2004) has been prepared by Technical Committee CEN/TC 164 “Water supply”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2005, and conflicting national standards shall be withdrawn at the latest by May 2005. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. SIST EN 14664:2005
EN 14664:2004 (E) 4 Introduction In respect of potential adverse effects on the quality of water intended for human consumption, caused by the product covered by this document: a) This document provides no information as to whether the product may be used without restriction in any of the Member States of the EU or EFTA; b) It should be noted that, while awaiting the adoption of verifiable European criteria, existing national regulations concerning the use and/or the characteristics of this product remain in force. NOTE Conformity with this document does not confer or imply acceptance or approval of the product in any or the Member States of the EU or EFTA. The use of the product covered by this document is subject to regulation or control by National Authorities.
SIST EN 14664:2005
EN 14664:2004 (E) 5 1 Scope This standard is applicable to iron (III) sulfate solid used for treatment of water intended for human consumption. It describes the characteristics of iron (III) sulfate solid and specifies the requirements and the corresponding analytical methods for iron (III) sulfate solid (analytical methods are given in Annex C) and gives information on its use in water treatment. It also determines the rules relating to safe handling and use of iron (III) sulfate solid (see Annex B). 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 any amendments) applies. EN ISO 3696, Water for analytical laboratory use – Specification and test methods (ISO 3696:1987) ISO 3165, Sampling of chemical products for industrial use – Safety in sampling ISO 5790:1979, Inorganic chemical products for industrial use – General method for the determination of chloride content - Mercurimetric method ISO 6206, Chemical products for industrial use – Sampling - Vocabulary ISO 8213, Chemical products for industrial use – Sampling techniques – Solid chemical products in the form of particles varying from powders to coarse lumps 3 Description 3.1 Identification 3.1.1 Chemical name Iron (III) sulfate solid. 3.1.2 Synonym or common names Ferric sulfate solid. 3.1.3 Relative molecular mass 561,9. 3.1.4 Empirical formula Fe2(SO4)3. x H2O where x is approximately 5,5. 3.1.5 Chemical formula Fe2(SO4)3. x H2O where x is approximately 5,5. SIST EN 14664:2005
EN 14664:2004 (E) 6 3.1.6 CAS Registry Number 1) 10028-22-5. 3.1.7 EINECS reference 2) 233-072-9. 3.2 Commercial form The iron (IlI) sulfate solid is available as free flowing granules or powder, with a particle size range from 0,1 mm to 10 mm and 0,055 mm to 0,060 mm respectively and the angle of repose is approximately 37. 3.3 Physical properties 3.3.1 Appearance The iron (III) sulfate solid consists of greyish or yellowish granules. 3.3.2 Density The bulk density is approximately equal to 1 300 kg/m3 for granules and 1 000 kg/m3 for powders at 20 °C. 3.3.3 Solubility (in water) Iron (III) sulfate solid dissolves rapidly in water. The solubility is approximately 550 g/l, corresponding to approximately mass fraction 11 % of Fe at 20 °C. At concentrations lower than mass fraction of 0,3 % Fe, hydrolysis and formation of iron (III) hydroxide will occur. 3.3.4 Vapour pressure Not known. 3.3.5 Boiling point at 100 kPa 3) Not applicable. 3.3.6 Melting point Iron (IIl) sulfate solid decomposes when heated. 3.3.7 Specific heat Not known. 3.3.8 Viscosity (dynamic) Not applicable.
1) Chemical Abstract Service Registry Number. 2) European Inventory of Existing Commercial Chemical Substances. 3) 100 kPa = 1 bar. SIST EN 14664:2005
EN 14664:2004 (E) 7 3.3.9 Critical temperature Not applicable. 3.3.10 Critical pressure Not applicable. 3.3.11 Physical hardness The granule strength is higher than 50 N. 3.4 Chemical properties Iron (III) sulfate solid is slightly hygroscopic at relative humidity higher than 50 %. Iron (III) sulfate solutions are acidic. 4 Purity criteria 4.1 General This document specifies the minimum purity requirements for iron (III) sulfate solid used for the treatment of water intended for human consumption. Limits are given for impurities commonly present in the product. Depending on the raw material and the manufacturing process other impurities may be present and, if so, this shall be notified to the user and when necessary to relevant authorities. NOTE Users of this product should check the national regulations in order to clarify whether it is of appropriate purity for treatment of water intended for human consumption, taking into account raw water quality, required dosage, contents of other impurities and additives used in the product not stated in this product standard. Limits have been given for impurities and chemical parameters where these are likely to be present in significant quantities from the current production process and raw materials. If the production process or raw materials lead to significant quantities of impurities, by-products or additives being present, this shall be notified to the user. 4.2 Composition of commercial product The product shall contain not less than mass fraction of 64 % of Fe2(SO4)3 or not less than a mass fraction of 18 % of Fe and shall be within ± 3 % of the manufacturer's declared values. 4.3 Impurities and main by-products The product shall conform to the requirements specified in Table 1. The concentration limits refer to Fe (III). SIST EN 14664:2005
EN 14664:2004 (E) 8 Table 1 – Impurities Impurity
Limit
Mass fraction in %
of Fe (III) content
Grade 1 Grade 2 Grade 3 Manganese max. 0,5 1 2 Iron(II) a max. 3,5 3,5 3,5 H2SO4 free max. 8 8 8 Insoluble mattersb
max. 10 10 10 a Fe (II) has a lower coagulant efficiency compared to Fe (III). Also hydrolysis of Fe (II) starts at pH value 8, and therefore Fe (II) can remain into the water at lower pH values b An excess of insoluble matters indicates the presence of foreign matter. Iron is a component of the product will usually be removed in the treatment process.
4.4 Chemical parameters The product shall conform to the requirements specified in Table 2. The concentration limits are specified in milligrams per kilogram of Fe (III). Table 2 – Chemical parameters Limit in mg/kg of Fe (III) Parameter Type 1 Type 2 Type 3 Arsenic (As) max. 1 20 50 Cadmium (Cd) max. 1 25 50 Chromium (Cr) max. 100 350 500 Mercury (Hg) max. 2,5 5 10 Nickel (Ni) max. 300 350 500 Lead (Pb) max. 2,5 100 400 Antimony (Sb) max. 10 20 60 Selenium (Se) max. 5 20 60 NOTE Cyanide (CN-) is usually not relevant because of the acidity of the product. Pesticides and polycyclic aromatic hydrocarbons are not relevant since the raw materials used in the manufacturing process are free of them. For maximum impact of iron (III) sulfate on trace metal content in drinking water see A.2. 5 Test methods 5.1 Sampling Observe the general recommendations in ISO 3165 and take into account ISO 6206. Prepare the laboratory sample required by the relevant procedure described in ISO 8213. SIST EN 14664:2005
EN 14664:2004 (E) 9 5.2 Analyses 5.2.1 Main product Iron (III) sulfate is determined as Fe (III) contents in the test sample. Fe (III) content is determined as the difference between total iron content and Fe (II) content (see C.1). 5.2.2 Impurities 5.2.2.1 Manganese The manganese content shall be determined by flame atomic absorption spectrometry (FAAS) (see C.2). 5.2.2.2 Iron (II) ( Fe (II)) The Fe (II) content is expressed as C(II) (see C.1.2.5.3). 5.2.2.3 Insoluble matter The mass fraction in % of the insoluble matter shall be determined in accordance with the method described in C.3. 5.2.2.4 Free acid The free acid shall be determined in accordance with the method described in C.4. 5.2.3 Chemical parameters 5.2.3.1 Preparation of sample solution 5.2.3.1.1 General Oxidation and wet digestion is used to bring the samples into a stable solution. 5.2.3.1.2 Principle Oxidation with hydrogen peroxide (H2O2) followed by digestion with hydrochloric acid (HCl). 5.2.3.1.3 Reagents 5.2.3.1.3.1 All reagents shall be of a recognized analytical grade and the water used shall conform to the grade 3 specified in EN ISO 3696. 5.2.3.1.3.2 Hydrochloric acid (HCl), solution, mass fraction 30 %. 5.2.3.1.3.3 Hydrogen peroxide (H2O2), solution, mass fraction 30 %. 5.2.3.1.4 Apparatus 5.2.3.1.4.1 Ordinary laboratory apparatus and glassware together with the following 5.2.3.1.4.2 Analytical balance. 5.2.3.1.4.3 Graduated cylinder, 50 ml. 5.2.3.1.4.4 Round flask with reflux condenser. SIST EN 14664:2005
EN 14664:2004 (E) 10 5.2.3.1.4.5 Hot plate. 5.2.3.1.4.6 Volumetric flask, 200 ml. 5.2.3.1.5 Procedure Dissolve with 20 ml of water 20,0 g of the iron salt. Filter and wash the filter cake with hot water. Add to the mixed filtrate and wash water 5 ml hydrogen peroxide solution (5.2.3.1.3.3) to iron (III)-samples. After adding 50 ml hydrochloric acid (5.2.3.1.3.2) boil the solution for 15 min by using a reflux condenser (5.2.3.1.4.4). Cool down the solution, transfer to a 200 ml volumetric flask (5.2.3.1.4.6) and fill up to the mark with water. This is the sample solution. 5.2.3.2 Arsenic The arsenic content shall be determined by hydride generation atomic absorption spectrometry (see C.5). 5.2.3.3 Cadmium The cadmium content shall be determined by graphite furnace atomic absorption spectrometry (see C.7). 5.2.3.4 Chromium The chromium content shall be determined by graphite furnace atomic absorption spectrometry (see C.7). 5.2.3.5 Mercury The mercury content shall be determined by cold vapour atomic absorption spectrometry (see C.6). 5.2.3.6 Nickel The nickel content shall be determined by graphite furnace atomic absorption spectrometry (see C.7). 5.2.3.7 Lead The lead content shall be determined by graphite furnace atomic absorption spectrometry (see C.7). 5.2.3.8 Antimony The antimony content shall be determined by hydride generation atomic absorption spectrometry (see C.5). 5.2.3.9 Selenium The selenium content shall be determined by hydride generation atomic absorption spectrometry (see C.5). 6 Labelling - Transportation - Storage 6.1 Means of delivery The product shall be delivered in suitable packages, paper of plastics bags, or by rubber-lined or plastics-lined bulk truck. In order that the purity of the product is not affected, the means of delivery shall not have been used previously for any different product or it shall have been specially cleaned and prepared before use. SIST EN 14664:2005
EN 14664:2004 (E) 11 6.2 Risk and safety labelling according to the EU Directives 4) The following labelling requirements shall apply to iron (III) sulfate solid at the date of the publication of this document. symbols and indications of danger : Xi : Irritant; Xn Harmful nature of special risks attributed to dangerous substances: R 22: Harmful by ingestion; R 36/37/38 : Irritating to eyes, respiratory system and skin; safety advice concerning dangerous substances: S 26 : In case of contact with eyes, rinse immediately with plenty of water and seek medical advice; S 28 : After contact with skin, wash immediately with plenty of water; S 37/39 : Wear suitable gloves and eye/face protection. NOTE Annex I of the Directive 67/548/EEC on Classification, packaging and labelling of dangerous substances and its amendments and adaptations in the European Union contains a list of substances classified by the EU. Substances not in this Annex 1 should be classified on the basis of their intrinsic properties according to the criteria in the Directive by the person responsible for the marketing of the substance. 6.3 Transportation regulations and labelling Iron (III) sulfate solid is not listed under a UN number 5). Iron (III) sulfate solid is not classified as a dangerous product for road, rail, sea and air transportation. 6.4 Marking The marking shall include the following information: name "iron(III) sulfate solid",
trade name, grade and
type; net mass; name and the address of the supplier and/or manufacturer; statement "this product conforms to EN 14664". 6.5 Storage 6.5.1 General Iron (III) sulfate solid is not corrosive.
4) See [2]. 5) United Nations Number. SIST EN 14664:2005
EN 14664:2004 (E) 12 6.5.2 Long term stability Iron (III) sulfate solid is stable at relative humidity lower than 50 %. 6.5.3 Storage incompatibilities Avoid contact with water because iron (III) sulfate solution formed is acidic and corrosive. SIST EN 14664:2005
EN 14664:2004 (E) 13 Annex A (informative)
General information on iron (III) sulfate solid A.1 Origin A.1.1 Raw materials The product is manufactured from sulfuric acid, iron (II) sulfate and oxygen. A.1.2 Manufacturing process Iron (III) sulfate solid is produced by dissolving iron (II) sulfate in sulfuric acid with oxygen as oxidant at elevated temperature followed by granulation or as powder produced by atomized drier of liquid iron (III) sulfate. A.2 Quality of commercial product The three types of iron (III) sulfate solid specified in Table 2 reflect the quality of commercially available products. Figures A.1 to A.3 show the maximum concentrations of trace metals that would be added to the raw water by the addition of products corresponding to the purity levels specified in Table 2. It can be seen that the concentrations of metal added are well below the Parametric Values given in the EU Directive 98/83/EC (see [1]) at typical product doses. Furthermore, the figures overstate the concentration of metals that would be present in the treated water since a substantial proportion of the trace metals will be incorporated in the sludge. Users of this product should select an appropriate grade an Type to enable them to achieve treated water quality targets taking into account raw water characteristics, required dosage, process plant conditions and other relevant factors. SIST EN 14664:2005
EN 14664:2004 (E) 14
Element Drinking water limit ug/l As 10 Cd 5 Cr 50 Hg 1 Ni 20 Pb 10 Sb 5 Se 10 Key 1 Maximum addition to water
µg/l metal 2 Product dosage mg/l Fe – Typical dose Figure A.1 – Maximum impact of iron (III) sulfate solid, Type 1, on trace metal content of water SIST EN 14664:2005
EN 14664:2004 (E) 15
Element Drinking water limit ug/l As 10 Cd 5 Cr 50 Hg 1 Ni 20 Pb 10 Sb 5 Se 10 Key 1 Maximum addition to water
µg/l metal 2 Product dosage mg/l Fe – Typical dose Figure A.2 – Maximum impact of iron (III) sulfate solid, Type 2, on trace metal content of water SIST EN 14664:2005
EN 14664:2004 (E) 16
Element Drinking water limit ug/l As 10 Cd 5 Cr 50 Hg 1 Ni 20 Pb 10 Sb 5 Se 10 Key 1 Maximum addition to water
µg/l metal 2 Product dosage mg/l Fe – Typical dose Figure A.3 – Maximum impact of iron (III) sulfate solid, Type 3, on trace metal content of water SIST EN 14664:2005
EN 14664:2004 (E) 17 A.3 Use A.3.1 Function The product is used as primary coagulant. A.3.2 Form in which it is used The product in used as delivered or dissolved in water. A.3.3 Treatment dose The treatment dose is variable depending on raw water quality and corresponds to a treatment dose between 4 g/m3 and 10 g/m3 expressed as Fe. A.3.4 Means of application Product can be dosed continuously from a silo by a dry feeder into a solution tank for continuously overflowing into the raw water. To promote a rapid dispersion a high turbulence at the point of addition is desirable. Iron (III) sulfate solution is acidic and equipments in contact with the solution therefore should be made of corrosion resistant materials (stainless, plastics, rubber, lead etc). A.3.5 Secondary effects Increase of the sulfate content. Reduction of alkalinity and pH value. A.3.6 Removal of excess product The coagulation process includes the hydrolysis of the ferric ions to ferric hydroxide. This precipitate is removed by sedimentation, flotation and/or finally filtration.
SIST EN 14664:2005
EN 14664:2004 (E) 18 Annex B (normative)
General rules relating to safety B.1 Rules for safe handling and use The supplier shall provide current safety instructions. B.2 Emergency procedures B.2.1 First aid In case of contact with skin, wash with plenty of water. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. If swallowed, provided patient is conscious, wash out the mouth with water and mass fraction of 5 % sodium bicarbonate solution and give a demulcent such as milk. Seek medical advice immediately
B.2.2 Spillage Small spillage: wash away with large quantities of water. Large spillage: neutralize with lime or soda ash, then dispose of according to local regulations. Water can be used if washings can go to drain. Immediately inform police and local authorities if product has entered public drains or waterways. B.2.3 Fire Product is not combustible. However, in contact with metals, iron (III) sulfate can liberate the flammable gas hydrogen.
SIST EN 14664:2005
EN 14664:2004 (E) 19 Annex C (normative)
Analytical methods C.1 Determination of iron (III) sulfate C.1.1 Total iron C.1.1.1 General This method applies to products with iron contents greater than a mass fraction of 0,4 %. C.1.1.2 Principle Iron is reduced by tin (II) chloride and is subsequently titrated with potassium dichromate solution. C.1.1.3 Reagents All reagents shall be of a recognized analytical grade and the water used shall conform to the grade 3 specified in EN ISO 3696. C.1.1.3.1 Hydrochloric acid, HCl concentrated, density ρ = 1,19 g/ml. C.1.1.3.2 Tin (II) chloride solution, c(SnCl2.2H2O) = 0,5 mol/l. Dissolve 22,6 g of SnCl2 .2H2O with 20 ml of hydrochloric acid (C.1.1.3.1) and dilute with water to 200 ml. Keep this solution in the dark. C.1.1.3.3 Mercury (II) chloride, saturated solution c(HgCl2) = 0,27 mol/l. C.1.1.3.4 Sulfuric acid, H2SO4 concentrated, density ρ = 1,84 g/ml. C.1.1.3.5 Phosphoric acid, H3PO4 concentrated, density ρ = 1,71 g/ml. C.1.1.3.6 Barium diphenylamine sulfonate solution, c(Ba(C6H5-NH-C6H4SO3)2) = 8 mmol/l. C.1.1.3.7 Potassium dichromate solution, c(K2Cr2O7) = 0,0166 mol/l. C.1.1.4 Apparatus Ordinary laboratory apparatus and glassware. C.1.1.5 Procedure C.1.1.5.1 Test solution Weigh about, to the nearest 0,1 mg, 7 g of the laboratory sample and dissolve in 150 ml water. Remove insoluble matters by filtering. Wash the filter cake with hot water. Transfer filtrate and wash water to a 200 ml volumetric flask, dilute to the mark with water.
SIST EN 14664:2005
EN 14664:2004 (E) 20 C.1.1.5.2 Determination Pipette 10 ml of the test solution and transfer to a 500 ml conical flask. Add some drops of hydrochloric acid (C.1.1.3.1) and heat until boiling while stirring. Add drop by drop tin (II) chloride solution (C.1.1.3.2) until discoloration. Reduction shall be achieved with great care. Two drops of tin (II) chloride (C.1.1.3.2) are necessary, more shall be avoided. Cool the solution rapidly in cool water. Add 10 ml of mercury (II) chloride (C.1.1.3.3). Dilute to 200 ml and wait 3 min. A slight white cloud will appear regarding to mercury (II) chloride addition. If a precipitate appears, stop the titration and reduce another aliquot of the test solution. Add 10 ml of sulfuric acid (C.1.1.3.4) and 10 ml of phosphoric acid (C.1.1.3.5). NOTE An alternative reduction method is given in Annex D. Titrate the test solution with potassium dichromate (C.1.1.3.7) with a volumetric burette and add five drops of barium diphenylamine sulfonate (C.1.1.3.6) near the end-point. End-point is achieved when a persistent purple colour appears. Record the volume (V) of potassium dichromate required for the complete titration. SAFETY PRECAUTIONS — Collect the residual solutions obtained from titrations and treat them in accordance with Annex B of ISO 5790:1979, in order to prevent pollution of waste water. C.1.1.5.3 Expression of results The total iron content, Ctot expressed in mass fraction in %, is given by the following equation: mVCtot16,11×= where V is the volume, in millilitres, of potassium dichromate required for the titration; m is the mass, in grams, of the sample used for the test solution. C.1.2 Determination of iron(II) ( Fe(II)) C.1.2.1 General This method applies to products with iron contents greater than a mass fraction of 0,4 %. C.1.2.2 Principle Iron is directly titrated with potassium dichromate solution. C.1.2.3 Reagents All reagents shall be of a recognized analytical grade and the water used shall conform to the Grade 3 specified in EN ISO 3696. C.1.2.3.1 Sulfuric acid, H2SO4 concentrated, density ρ = 1,84 g/ml. C.1.2.3.2 Phosphoric acid, H3PO4 concentrated, density ρ = 1,71 g/ml. SIST EN 14664:2005
EN 14664:2004 (E) 21 C.1.2.3.3 Barium diphenylamine sulfonate solution, c(Ba(C6H5-NH-C6H4SO3)2) = 8 mmol/l. C.1.2.3.4 Potassium dichromate solution, c(K2Cr2O7) = 0,0166 mol/l. C.1.2.4 Apparatus Ordinary laboratory apparatus and glassware. C.1.2.5 Procedure C.1.2.5.1 Test solution In a 500 ml conical flask, pour 200 ml of water, add 10 ml of sulfuric acid (C.1.2.3.1) and 10 ml of phosphoric acid (C.1.2.3.2). Cool with water. Pipette 100 ml from the volumetric flask in C.1.1.5.1 and transfer to the conical flask containing the acid solution. C.1.2.5.2 Determination Titrate the test solution with potassium dichromate (C.1.2.3.4) with a volumetric burette and add five drops of barium diphenylamine sulfonate (C.1.2.3.3) near the end-point. End-point is achieved when a persistent purple colour appears, record the volume (V) of potassium dichromate required for the complete titration. C.1.2.5.3 Expression of results The iron(II) content, C(II) expressed in mass fraction in
%, is given by the following equation : mVC113,1×=(II) where V is the volume, in millilitres, of potassium dichromate required for the titration; m is the mass, in grams, of the sample used for the test solution. C.1.3 Determination of iron (III) ( Fe (III)) The iron (III) content, C(III) expressed in mass fraction in %, is given by the following equation: (II)(III)CCCtot−= where Ctot is the total iron content (C.1.1.5.3), expressed as mass fraction; C(II) is the iron (II) content (C.1.2.5.3), expressed as mass fraction. C.2 Determination of manganese C.2.1 General This method is applicable to iron salts or iron solutions with manganese content greater than mass fraction of 0,05 %. SIST EN 14664:2005
EN 14664:2004 (E) 22 C.2.2 Principle Iron salts are diluted in water. Manganese is determined in this diluted solution by direct injection of the solution into the flame of an atomic absorption spectrometer. Manganese is converted to the atomic state by thermal dissociation. The absorption of the atoms is measured in the light path of the FAAS at a wavelength specific to the element. The concentrations are calculated by means of a calibration curve. C.2.3 Reagents All reagents shall be a recognized analytical grade, water shall conform to the Grade 3 specified in EN ISO 3696 and ultra pure grade acid shall be used. C.2.3.1 Hydrochloric acid (HCl), solution of mass fraction 30 %. C.2.3.2 Manganese, standard stock solution, c0 (Mn) = 1 g/l. C.2.3.3 Manganese, intermediate standard solution, c1 (Mn) = 100 mg/l : Pipette 10 ml of standard stock solution (C.2.3.2) into a 100 ml volumetric flask (C.2.4.1), add 3 ml of hydrochloric acid (C.2.3.1) and dilute to the mark with water. C.2.3.4 Manganese, standard solution, c2 (Mn) = 0,5 mg/l : Pipette 0,5 ml of intermediate standard solution (C.2.3.3) into a 100 ml volumetric flask (C.2.4.1) and dilute to the mark with water . C.2.3.5 Manganese, standard solution, c3 (Mn) = 1 mg/l : Pipette 1 ml of intermediate standard solution (C.2.3.3) into a 100 ml volumetric flask (C.2.4.1) and dilute to the mark with water . C.2.3.6 Manganese, standard solution, c4 (Mn) = 2 mg/l : Pipette 2 ml of intermediate standard solution (C.2.3.3) into a 100 ml volumetric flask (C.2.4.1) and dilute to the mark with water . C.2.3.7 Manganese, standard solution, c5 (Mn) = 3 mg/l : Pipette 3 ml of intermediate standard solution (C.2.3.3) into a 100 ml volumetric flask (C.2.4.1) and dilute to the mark with water . C.2.3.8 Blank solution : Pipette 3 ml of hydrochloric acid (C.2.3.1) into a 200 ml volumetric flask (C.2.4.1) and dilute to the mark with water . C.2.4 Apparatus Ordinary laboratory apparatus and glassware together with the following
C.2.4.1 Volumetric flasks, 100 ml and 200 ml. C.2.4.2 Analytical balance with an accuracy of 0,1 mg. C.2.4.3 Flame atomic absorption spectrometer. C.2.4.4 Electrode-less discharge or hollow cathode lamp for the determination of manganese. C.2.5
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