EN 12124:2005

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kemikalije, ki se uporabljajo za pripravo pitne vode - Natrijev sulfitProdukte zur Aufbereitung von Wasser für den menschlichen Gebrauch - NatriumsulfitProduits chimiques utlisés pour le traitement de l'eau destiné a la consommation humaine - Sulfite de sodiumChemicals used for treatment of water intended for human consumption - Sodium sulfite71.100.80Chemicals for purification of water13.060.20Pitna vodaDrinking waterICS:Ta slovenski standard je istoveten z:EN 12124:2005SIST EN 12124:2005en01-september-2005SIST EN 12124:2005SLOVENSKI
STANDARDSIST EN 12124:20001DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 12124
June 2005 ICS 71.100.80
Supersedes EN 12124:1998
English version
Chemicals used for treatment of water intended for human consumption - Sodium sulfite
Produits chimiques utlisés pour le traitement de l'eau destiné à la consommation humaine - Sulfite de sodium
Produkte zur Aufbereitung von Wasser für den menschlichen Gebrauch - Natriumsulfit This European Standard was approved by CEN on 12 May 2005.
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 lists and bibliographical references concerning such national standards 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 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.
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 STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
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B-1050 Brussels © 2005 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12124:2005: ESIST EN 12124:2005

General information on sodium sulfite.16 Bibliography.18
3.1.4 Empirical formula Na2SO3. 3.1.5 Chemical formula Na2SO3. 3.1.6 CAS-Registry Number1)
7757-83-7 3.1.7 EINECS reference2)
231-821-4. 3.2 Commercial form The product is a crystalline powder. 3.3 Physical properties 3.3.1 Appearance and odour The product is a white, fine crystalline, odourless powder. 3.3.2 Density The density of the product is 2,63 g/cm³ at 20 °C. The bulk density is 1,2 g/cm³ to 1,5 g/cm³ at 20 °C.
3.3.3 Solubility in water The solubility of the product in water is 250 g/l at 20 °C. 3.3.4 Vapour pressure Not applicable. 3.3.5 Boiling point at 100 kPa3)
The product decomposes above 230 °C. 3.3.6 Crystallisation point See 3.3.5.
1) Chemical Abstracts Service Registry Number. 2) European Inventory of Existing Commercial Chemical Substances. 3) 100 kPa = 1 bar. SIST EN 12124:2005

Table 1 – Chemical parameters
Parameter Limit mg/kg of commercial product Antimony (Sb) max. 2 Arsenic (As) max. 1 Cadmium (Cd) max. 1 Chromium (Cr) max. 1 Lead (Pb) max. 2 Mercury (Hg) max. 0,5 Nickel (Ni) max. 1 Selenium (Se) max. 1 NOTE: Pesticides and polycyclic aromatic hydrocarbons and cyanides ( CN- ) are not relevant in sodium sulfite because the raw materials used in the manufacturing are free of them. For parametric values of sodium sulfite on trace metal content in drinking water, see [1].
5 Test methods 5.1 Sampling Observe the general recommendations of ISO 3165 and take account of ISO 6206. Prepare the laboratory sample(s) required by the relevant procedure described in ISO 8213. 5.2 Analyses 5.2.1 Main product The sodium sulfite content shall be determined in accordance with ISO 418. NOTE Both methods, direct titration and back titration, can be used. SIST EN 12124:2005

AAS 193,7 n.a. Sb see 5.2.3.3 Hydride
AAS 217,6 n.a. Cd ISO 6353-1 GM 29see 5.2.3.2 AAS 228,8 air-acetylene Cr ISO 6353-1 GM 29see 5.2.3.2 AAS 357,8 air-acetylene Pb ISO 6353-1 GM 29see 5.2.3.2 AAS 217,0 or 283,3 air-acetylene Ni ISO 6353-1 GM 29see 5.2.3.2 AAS 232,0 oxidizing acetylene-air Se see 5.2.3.3 Hydride
AAS 196,0 n.a. Hg in accordance withISO 5993 flameless
AAS 253,6 n.a. AAS = Atomic Absorption Spectroscopy n.a. = not applicable 5.2.3.2 Determination of cadmium (Cd), chromium (Cr), lead (Pb) and nickel (Ni) 5.2.3.2.1
Principle The elements cadmium (Cd), chromium (Cr), lead (Pb) and nickel (Ni) are determined using atomic absorption spectrometry with the standard additions technique. SIST EN 12124:2005

Apparatus Ordinary laboratory apparatus and the following: 5.2.3.2.3.1 Atomic absorption spectrometer with the measurement parameters specified in Table 2. 5.2.3.2.4
Procedure 5.2.3.2.4.1 Test portion Weigh 1 g (m) to the nearest 0,01 mg of the laboratory sample into a 100 ml one-mark volumetric flask and make up to the mark at 20 °C with water. 5.2.3.2.4.2 Determination The reference solutions shall be made by spiking the sample with the standard solutions, which contain stepwise increasing contents of the elements to be determined. NOTE The amount of internal standard to be added can be estimated from a preliminary investigation, determining roughly the element conten
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