SIST EN 16279:2012
(Main)Animal feeding stuffs - Determination of fluoride content after hydrochloric acid treatment by ion-sensitive electrode method (ISE)
Animal feeding stuffs - Determination of fluoride content after hydrochloric acid treatment by ion-sensitive electrode method (ISE)
This European Standard specifies an Ion-Selective Electrode method (ISE) after hydrochloric acid treatment for the determination of fluoride from animal feeding stuffs. The content of fluoride (F-) corresponds to that of fluorine (F) specified in Commission Regulation (EU) 574/2011. This European Standard is strictly based on several conventions such as those contained in the following example: 0,5 g test portion for extraction of fluoride from animal feeds by means of an acid treatment with 20 ml of 1 mol/l hydrochloric acid solution at ambient temperature (20 °C to 25 ?C) for 20 min. The pH is controlled and adjusted to 5,5 in the buffered test solution before determination of fluoride by ISE using standard addition technique. The method was successfully tested in an interlaboratory study in concentrations between 100 mg/kg up to 500 mg/kg. If this method is followed strictly, then theoretically all concentrations from 40 mg/kg up to 4 000 mg/kg can be analysed within the linear calibration function. Only for concentrations lower than 40 mg/kg is the use of an interpolation technique required instead of standard addition Annex C. The quantification limit for fluoride using the conventions of the method including the standard addition technique is 40 mg/kg or lower than 2,5 mg/kg when using interpolation Annex C.
Futtermittel - Bestimmung des Fluoridgehaltes nach Salzsäure-Behandlung mittels ISE-Verfahren
In der vorliegenden Europäischen Norm wird ein Verfahren mit ionenselektiver Elektrode (ISE) zur Bestimmung von Fluorid in Futtermitteln nach Behandlung mit Salzsäure festgelegt. Diese Europäische Norm beruht streng auf mehreren Festlegungen, wie z. B. der Verwendung einer Prüfmenge von 0,5 g für die Extraktion von Fluorid aus Futtermitteln mittels einer Säurebehandlung mit Salzsäure (1 mol/l) bei Umgebungstemperatur (20 °C bis 25 °C) für genau 20 min und der Kontrolle und Einstellung des pH-Wertes auf 5,5 in der gepufferten Prüflösung vor der Bestimmung von Fluorid mit ISE unter Anwendung des Verfahrens der Standardaddition. Das Verfahren wurde erfolgreich in einem Ringversuch mit Konzentrationen von 100 mg/kg bis zu 500 mg/kg geprüft. Bei einer genauen Einhaltung des vorliegenden Verfahrens sind theoretisch alle Konzentrationen von 40 mg/kg bis zu 4 000 mg/kg innerhalb der linearen Kalibrierfunktion zu analysieren. Nur bei Konzentrationen von weniger als 40 mg/kg ist die Anwendung des Interpolationsverfahrens anstelle des Verfahrens der Standardaddition erforderlich (Anhang C). Bei Anwendung der Festlegungen des Verfahrens beträgt die Bestimmungsgrenze mit dem Verfahren der Standardaddition 40 mg/kg bzw. weniger als 2,5 mg/kg bei Anwendung der Interpolation (Anhang C).
Aliments des animaux - Détermination de la teneur en fluorure, après traitement à l'acide chlorhydrique, selon la méthode des électrodes sélectives d'ions (ISE)
La présente Norme européenne spécifie une méthode des électrodes sélectives d’ions (ISE) après traitement à l’acide chlorhydrique pour le dosage du fluorure dans les aliments des animaux.
La présente Norme européenne repose strictement sur plusieurs conventions telles que l’utilisation d’une prise d’essai de 0,5 g pour l’extraction du fluorure des aliments des animaux par traitement à l’acide chlorhydrique à 1 mol/l à température ambiante (20 °C à 25 °C) pendant exactement 20 min, ainsi que le contrôle et l’ajustement du pH à 5,5 dans la solution d’essai tamponnée avant le dosage du fluorure par ISE en utilisant la technique des ajouts dosés.
La méthode a passé avec succès un essai interlaboratoires à des concentrations comprises entre 100 mg/kg et 500 mg/kg. En respectant strictement cette méthode, toutes les concentrations comprises entre 40 mg/kg et 4 000 mg/kg sont théoriquement destinées à être analysées à l’aide de la fonction d’étalonnage linéaire.
Pour les concentrations inférieures à 40 mg/kg uniquement, l’utilisation de la technique d’interpolation à la place de la technique des ajouts dosés est requise (Annexe C).
La limite de quantification pour le fluorure, en utilisant les conventions de la méthode, dont la technique des ajouts dosés, est de 40 mg/kg ou de moins de 2,5 mg/kg avec l’interpolation (Annexe C).
Živalska krma - Določevanje fluorida po obdelavi s solno kislino z metodo ionsko občutljive elektrode (ISE)
Ta evropski standard določa metodo ionsko občutljive elektrode (ISE) po obdelavi s solno kislino za določevanje fluorida v živalski krmi. Vsebnost fluorida (F-) je enaka vsebnosti fluora (F) iz Uredbe Komisije (EU) št. 574/2011. Ta evropski standard strogo upošteva več dogovorov, na primer: preskusni vzorec z maso 0,5 g za ekstrakcijo fluorida iz živalske krme po 20-minutni obdelavi z 20 ml 1 mol/l solne kisline pri temperaturi okolja (20 °C do 25 °C). Vrednost pH pufrske preskusne raztopine se nadzoruje in pred določevanjem fluorida z metodo ionsko občutljive elektrode prilagodi na 5,5 s standardno tehniko dodajanja. Metoda je bila uspešno preskušena v medlaboratorijski študiji pri koncentracijah od 100 mg/kg do 500 mg/kg. Ob natančni uporabi te metode je teoretično možna analiza vseh koncentracij 40 mg/kg do 4 000 mg/kg z linearno funkcijo kalibracije. Tehnika interpolacije se namesto standardnega dodajanja zahteva samo za koncentracije, nižje od 40 mg/kg; glejte dodatek C. Meja kvantifikacije fluorida je ob uporabi dogovorov iz metode, vključno s standardno tehniko dodajanja, 40 mg/kg ali manj kot 2,5 mg/kg, če se uporablja interpolacija; glejte dodatek C.
General Information
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Futtermittel - Bestimmung des Fluoridgehaltes nach Salzsäure-Behandlung mittels ISE-VerfahrenAliments des animaux - Détermination de la teneur en fluorure, après traitement à l'acide chlorhydrique, selon la méthode des électrodes sélectives d'ions (ISE)Animal feeding stuffs - Determination of fluoride content after hydrochloric acid treatment by ion-sensitive electrode method (ISE)65.120KrmilaAnimal feeding stuffsICS:Ta slovenski standard je istoveten z:EN 16279:2012SIST EN 16279:2012en,fr,de01-september-2012SIST EN 16279:2012SLOVENSKI
STANDARD
SIST EN 16279:2012
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16279
July 2012 ICS 65.120 English Version
Animal feeding stuffs - Determination of fluoride content after hydrochloric acid treatment by ion-sensitive electrode method (ISE)
Aliments des animaux - Détermination de la teneur en fluorure, après traitement à l'acide chlorhydrique, selon la méthode utilisant une électrode sélective d'ions (ISE)
Futtermittel - Bestimmung des Fluoridgehaltes nach Salzsäure-Behandlung mit ionensensitiver Elektrode (ISE)This European Standard was approved by CEN on 17 May 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 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 under 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, Former Yugoslav Republic of Macedonia, France, 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
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR 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 16279:2012: ESIST EN 16279:2012
EN 16279:2012 (E) 2 Contents Page Foreword .3Introduction .41Scope .52Normative references .53Principle .54Reagents .65Apparatus .76Sampling .77Preparation of test sample .78Procedure .89Calculation and expression of results . 1010Precision . 1211Test report . 13Annex A (informative)
Results of the interlaboratory study . 14Annex B (informative)
Flowchart – Determination of fluoride content after hydrochloric acid treatment by ISE method . 15Annex C (informative)
Interpolation reading . 16Bibliography . 18 SIST EN 16279:2012
EN 16279:2012 (E) 3 Foreword This document (EN 16279:2012) has been prepared by Technical Committee CEN/TC 327 “Animal Feeding stuffs – Methods of sampling and analysis”, the secretariat of which is held by NEN. 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 January 2013, and conflicting national standards shall be withdrawn at the latest by January 2013. 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 for identifying any or all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. 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, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, 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. SIST EN 16279:2012
EN 16279:2012 (E) 4 Introduction Fluorine (F) is one of the most abundant elements in the environment. Animals are exposed to the ionic form of the element, fluoride (F-), which may be present in feeding stuffs. The toxicity of fluoride has already been established by EFSA [6]; and its availability greatly depends on the solubility of fluoride compounds.
In particular, fluoride compounds with low solubility are poorly absorbed while fluoride ions released from readily soluble compounds are almost completely absorbed from the gastrointestinal tract by passive diffusion in monogastric species. The extraction procedure of this method involves a mild acid treatment with hydrochloric acid solution of 1 mol/l which should reflect the gastric hydrochloric acid concentration of 0,1 mol/l– 0,3 mol/l.
SIST EN 16279:2012
EN 16279:2012 (E) 5 1 Scope This European Standard specifies an Ion-Selective Electrode method (ISE) after hydrochloric acid treatment for the determination of fluoride from animal feeding stuffs. The content of fluoride (F-) corresponds to that of fluorine (F) specified in Commission Regulation (EU) 574/2011[3]. This European Standard is strictly based on several conventions such as those contained in the following example: EXAMPLE 0,5 g test portion for extraction of fluoride from animal feeds by means of an acid treatment with 20 ml of 1 mol/l hydrochloric acid solution at ambient temperature (20 °C to 25 ºC) for 20 min. The pH is controlled and adjusted to 5,5 in the buffered test solution before determination of fluoride by ISE using standard addition technique. The method was successfully tested in an interlaboratory study in concentrations between 100 mg/kg up to 500 mg/kg. If this method is followed strictly, then theoretically all concentrations from 40 mg/kg up to 4 000 mg/kg can be analysed within the linear calibration function. Only for concentrations lower than 40 mg/kg is the use of an interpolation technique required instead of standard addition Annex C. The quantification limit for fluoride using the conventions of the method including the standard addition technique is 40 mg/kg or lower than 2,5 mg/kg when using interpolation Annex C. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. 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 EN ISO 6498, Animal feeding stuffs
Guidelines for sample preparation
3 Principle For the determination of fluoride, a test portion of 0,5 g of the sample is treated with 20 ml of 1 mol/l hydrochloric acid solution for 20 min at ambient temperature (20 °C to 25 °C). The amount of fluoride extracted from the sample is determined by means of a fluoride selective electrode. NOTE This ISE method is based upon a potentiometric technique. This means that it is based upon the measurement of a concentration of an analyte present in solution, by means of an ion selective electrode. This electrode has a linear response within a working range of analyte concentrations, which is provided by the calibration curve. Thus, in general, the operator should take an adequate amount of sample to ensure that the final concentration of the analyte is within this working range given by the calibration step. To ensure satisfactory reproducibility of the method however, this extraction procedure as a convention method fixes the ratio of the amount of the test portion to the volume of the extraction solvent for all kind of feeds. WARNING — The use of this European Standard can involve hazardous materials, operations and equipment. This standard does not purport to address all the safety problems associated with its use. It is the responsibility of the user of this European Standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. SIST EN 16279:2012
EN 16279:2012 (E) 6 4 Reagents Use only reagents of recognised analytical grade, unless otherwise specified. 4.1 Water, complying with grade 2 in accordance with EN ISO 3696. 4.2 Element stock solution, fluoride (NaF); Fluoride c = 1 000 mg/l.
4.3 Hydrochloric acid (HCl), mass fraction of 37 %, having a density of approximately
(HCl) ~ 1,185 g/ml. 4.4 Perchloric acid (HClO4), mass fraction of 70 % to 72 %, having a density of approximately
(HClO4) ~ 1,68 g/ml. 4.5 Acetic acid (CH3COOH), glacial, 99 %.
4.6 Sodium acetate trihydrate (CH3COONa 3H2O), 99 %.
4.7 Trisodium citrate dihydrate (C6H5Na3O7 2H2O), 99 %.
4.8 Hydrochloric acid solution of 1 mol/l.
To prepare: pipette 83 ml hydrochloric acid (4.3) into a 1 000 ml volumetric flask (5.5) and fill to the mark with water (4.1). 4.9 Sodium acetate solution of 3 mol/l.
To prepare: dissolve 408 g of sodium acetate trihydrate (4.6) in 750 ml of water (4.1). When the solution reaches room temperature (20 °C to 25 °C), adjust the pH to 7,0 with acetic acid (4.5), transfer to a 1 000 ml volumetric flask (5.5) and dilute to the mark with water (4.1). 4.10 Sodium citrate solution.
To prepare: dissolve 222 g of trisodium citrate dehydrate (4.7) in 250 ml of water (4.1), add 28 ml perchloric acid (4.4), transfer to a 1 000 ml volumetric flask (5.5) and dilute to the mark with water (4.1). 4.11 Intermediate fluoride solution of 100 mg/l.
To prepare: pipette 10 ml from the 1 000 mg/l fluoride stock solution (4.2) into a 100 ml plastic volumetric flask (5.7) and dilute to the mark with water (4.1). 4.12 Intermediate fluoride solution of 10 mg/l.
To prepare: pipette 10 ml from the 100 mg/l intermediate fluoride solution (4.11) into a 100 ml plastic volumetric flask (5.7) and dilute to the mark with water (4.1). 4.13 Sodium hydroxide solution of 5 mol/l.
To prepare: transfer NaOH pellets, weighing 200 g, to a 1 000 ml volumetric flask (5.5), which is about 2/3 filled with water (4.1) and contains a magnetic stirring bar (5.4). Stir until dissolved; after cooling down take away the magnet stirrer and fill up to the mark with water (4.1) and shake.
NOTE The use of sodium hydroxide solution of 1 mol/l might be more applicable for a precise pH adjustment. SIST EN 16279:2012
EN 16279:2012 (E) 7 5 Apparatus Use typical laboratory apparatus with preference for plastic instead of glass for recipients, in order to avoid undesired reactions of fluoride with silicon from glass in the case of fluoride standard solutions and the test sample solutions. 5.1 Laboratory grinder 5.1.1 Laboratory grinder, capable of grinding to a particle size of less than or equal to 0,5 mm. 5.1.2 Laboratory grinder, capable of grinding to a particle size of less than or equal to 0,1 mm. 5.2 Analytical balance, capable of weighing to an accuracy of 0,1 mg. 5.3 Freeze drying equipment, capable of freeze-drying liquid animal feeding stuffs. 5.4 Magnetic stirrer, with polytetrafluoro-ethylene-coated stirring bar.
5.5 One-mark volumetric flasks, of capacities 100 ml, 500 ml and 1 000 ml. 5.6 Beakers, of capacities 100 ml and 250 ml. 5.7 One-mark plastic volumetric flasks, of capacities 100 ml and 200 ml. 5.8 Plastic beakers, of capacities 50 ml, 100 ml and 200 ml. 5.9 Fluoride selective electrode. NOTE The use of combined electrodes (i.e. selective and reference in one) is possible. 5.10 pH combined electrode. 5.11 Reference electrode for fluoride. 5.12 Ion-pH-meter, capable of measuring to an accuracy of 0,1 mV. 6 Sampling Sampling is not part of the method specified in this European Standard. A recommended sampling method is given in EN ISO 6497 [2]. It is important that the laboratory receives a sample that is truly representative and has not been damaged or changed during transport or storage. 7 Preparation of test sample 7.1 General Prepare the test sample in accordance with EN ISO 6498. The grinding must be performed in conditions such that the substance is not appreciably heated. The operation is to be repeated as many times as is necessary and it shall be executed as quickly as possible in order to prevent any gain or loss of constituents (such as water).
SIST EN 16279:2012
EN 16279:2012 (E) 8 The whole ground product is placed in a flask made of e.g. polypropylene, which can be stoppered and stored in such way to prevent any change in composition. Before any weighing is carried out for the analysis, the whole test sample shall be thoroughly mixed for reasons of homogeneity. 7.2 Animal feeding stuffs which can be ground as such Grind the laboratory sample (usually 500 g), using a grinder (5.1.1) or mortar, until a particle size of 0,5 mm or less has been reached. Use e.g. a knife mill or equivalent. 7.3 Liquid animal feeding stuffs 7.3.1 General Liquid feeding stuffs shall be pre-dried according to the procedure described in 7.3.2 or freeze-dried according to the procedure described in 7.3.3. 7.3.2 Pre-drying Pre-dry the laboratory sample at a temperature of (60 ± 5) °C during at least 16 h to reduce the moisture content to a level of 8 % to 12 %. Determine the mass of the sample before and after pre-drying using an analytical balance (5.2) and calculate the moisture loss on pre-drying. Grind the pre-dried sample in accordance with 7.1. 7.3.3 Freeze-drying Freeze-dry the laboratory sampl
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.