1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 15621:2012Animal feeding stuffs Determination of calcium,sodium, phosphorus,magnesium, potassium,sulphur, iron, zinc, copper,manganese and cobalt afterpressure digestion by
2、 ICP-AESBS EN 15621:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 15621:2012. It supersedes DD CEN/TS 15621:2007, which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e A W / 1 0 , A n i m a l f e e
3、 d i n g s t u f f s .A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012Pu
4、blished by BSI Standards Limited 2012ISBN 978 0 580 73050 4 ICS 65.120 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 February 2012.Amendments issued since p
5、ublicationDate T e x t a f f e c t e dBS EN 15621:2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15621 February 2012 ICS 65.120 Supersedes CEN/TS 15621:2007English Version Animal feeding stuffs - Determination of calcium, sodium, phosphorus, magnesium, potassium, sulphur, iron, zinc, coppe
6、r, manganese and cobalt after pressure digestion by ICP-AES Aliments pour animaux - Dosage du calcium, du sodium, du phosphore, du magnsium, du potassium, du soufre, du fer, du zinc, du cuivre, du manganse et du cobalt aprs digestion sous pression par ICP-AES Futtermittel - Bestimmung von Calcium, N
7、atrium, Phosphor, Magnesium, Kalium, Schwefel, Eisen, Zink, Kupfer, Mangan und Kobalt nach Druckaufschluss mittels ICP-AES This European Standard was approved by CEN on 30 December 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for givi
8、ng 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 offi
9、cial 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
10、 Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
11、Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR 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 15621:2012: EBS
12、 EN 15621:2012EN 15621:2012 (E) 2 Contents Page Foreword . 41 Scope . 52 Normative references . 53 Principle . 54 Reagents 55 Apparatus 66 Sampling 77 Preparation of the test sample 77.1 General . 77.2 Animal feeding stuffs which can be ground as such 77.3 Liquid animal feeding stuffs 87.3.1 General
13、 . 87.3.2 Pre-drying 87.3.3 Freeze-drying 87.4 Mineral animal feeding stuffs 88 Procedure 88.1 Pressure digestion Preparation of the blank test solution and the test solution . 88.1.1 General . 88.1.2 Example of microwave digestion 88.1.3 Example of a high pressure digestion 88.2 Calibration . 98.2.
14、1 General . 98.2.2 External calibration . 98.2.3 Standard addition technique . 98.3 Determination 98.3.1 General . 98.3.2 Determination by inductively coupled plasma atomic emission spectrometry 109 Calculation and expression of the result . 119.1 General . 119.2 External calibration . 119.3 Standar
15、d addition method with only one addition 119.4 Standard addition method with several additions 129.5 Calculation of the element content in the sample . 1310 Precision 1310.1 Inter-laboratory test 1310.2 Repeatability 1310.3 Reproducibility 1311 Test report . 19Annex A (informative) Results of the in
16、ter-laboratory test 20Annex B (informative) Notes on the detection technique, interferences and quantification, pressure digestion 36B.1 General . 36B.2 Interferences . 36B.3 Quantification and matrix matching . 37B.4 Pressure digestion conditions 38BS EN 15621:2012EN 15621:2012 (E) 3 Bibliography 4
17、0BS EN 15621:2012EN 15621:2012 (E) 4 Foreword This document (EN 15621:2012) has been prepared by Technical Committee CEN/TC 327 “Animal feeding stuffs”, 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 ident
18、ical text or by endorsement, at the latest by August 2012, and conflicting national standards shall be withdrawn at the latest by August 2012. 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 re
19、sponsible for identifying any or all such patent rights. This document supersedes CEN/TS 15621:2007. 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,
20、Cyprus, Czech Republic, Denmark, Estonia, Finland, 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. BS EN 15621:2012EN 15621:
21、2012 (E) 5 1 Scope This European Standard specifies a method for the determination of the minerals calcium, sodium, phosphorus, magnesium, potassium and sulphur and the elements iron, zinc, copper, manganese, cobalt in animal feeding stuffs by inductively coupled plasma atomic emission spectrometry
22、(ICP-AES) after pressure digestion. The method was fully statistically tested and evaluated within 11 animal feeding stuff samples for the minerals calcium, sodium, phosphorus, magnesium, potassium and sulphur and the elements iron, zinc, copper, manganese and cobalt. For potassium and sulphur the H
23、ORRAT values were mostly higher than 2. Therefore, for these elements the method is more applicable as a screening method and not for confirmatory purposes. Other elements like molybdenum, lead, cadmium, arsenic were not fully statistically tested and evaluated within 11 animal feeding stuff samples
24、 because these elements did not occur in concentrations higher than the limit of quantification in most of these samples. A single laboratory validation is therefore necessary for the use of this multi element method for these elements. The method limit of quantification for each element is dependen
25、t on the sample matrix as well as on the instrument. The method is not applicable for determination of low concentrations of elements. A limit of quantification of 1 mg/kg should normally be obtained. NOTE This method can also be used for the determination of minerals in products with high mineral c
26、ontent ( 5 %), yet for this purpose other more precise analytical techniques are available. 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
27、. 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) prEN ISO 6498, Animal feeding stuffs Guidelines for sample preparation (ISO/DIS 6498) 3 Principle For
28、 the determination of calcium, sodium, phosphorus, magnesium, potassium and sulphur, iron, zinc, copper, manganese, cobalt, molybdenum, lead, cadmium and arsenic a test portion of the sample is digested under pressure. The concentration of the elements is determined by inductively coupled plasma ato
29、mic emission spectrometry (ICP-AES) using external calibration or standard addition technique. 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 res
30、ponsibility of the user of this European Standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 4 Reagents Use only reagents of recognized analytical grade, and water conforming to grade 2 of EN ISO 3696. BS EN 15621:2012
31、EN 15621:2012 (E) 6 4.1 Nitric acid concentrated, not less than 65 % (mass fraction), c(HNO3) = 14,4 mol/l, having a density of approximately (HNO3) 1,42 g/ml. 4.2 Nitric acid solution, with a volume fraction of 2 %. To be prepared: pipette 20 ml nitric acid concentrated (4.1) in a 1 000 ml volumetr
32、ic flask (5.4) and fill to the mark with water. 4.3 Hydrogen peroxide, not less than 30 % (mass fraction). 4.4 Element stock solutions. Ca, Na, P, Mg, K, S, Fe, Zn, Cu, Mn, Co, Mo, Cd, Pb, As c = 1 000 mg/l. The user should choose a suitable stock solution. Both single-element stock solutions and mu
33、lti-element stock solutions with adequate specification stating the acid used and the preparation technique are commercially available. It is advisable to use certified stock solutions. NOTE Element stock solutions with concentrations different from 1 000 mg/l may be used as well. 4.5 Standard solut
34、ions. Depending on the scope, different multi-element standard solutions may be necessary. In general, when combining multi-element standard solutions, their chemical compatibility and the possible hydrolysis of the components shall be regarded. Spectral interferences from other elements present in
35、multi-element standards also need to be considered. Various combinations of elements at different concentrations can be used, provided that the stock standard solutions (4.4) are diluted with the same acid and equal concentration as the acid in the test solution to a range of standards that covers t
36、he concentrations of the elements to be determined. The multi-element standard solutions are considered to be stable for several months, if stored in the dark. 5 Apparatus Usual laboratory apparatus and, in particular, the following: NOTE For the determination of sodium in low concentrations it is a
37、dvisable not to use glassware since glassware can be a source of sodium contamination. 5.1 Laboratory grinder. 5.1.1 Laboratory grinder, capable of grinding to a particle size of less than or equal to 1 mm, e.g. a knife mill or equivalent. 5.1.2 Laboratory grinder, capable of grinding to a particle
38、size of less than or equal to 0,1 mm, e.g. a ball mill or equivalent. NOTE It should be checked that the mill used does not influence the concentration of elements in the sample (e.g. adsorption, contamination) which have to be analysed. 5.2 Analytical balance, capable of weighing to an accuracy of
39、1 mg. 5.3 Pressure digestion apparatus, commercially available. BS EN 15621:2012EN 15621:2012 (E) 7 The apparatus shall be tested for safety pressure vessels made of acid-resistant materials and having holders for the sample of acid-resistant material with low level of contamination by elements to b
40、e determined. Apparatus is available which uses a high-pressure incinerator with or without ambient autoclave pressure. Instead of polytetrafluoroethylene (PTFE) holders, it is better to use graduated quartz holders, fluorinated ethylene propylene (FEP) holders or perfluoroalkoxy (PFA) holders. Quar
41、tz is advisable to be used for decomposition temperatures above 230 C. 5.4 One-mark volumetric flasks, of capacity 1 000 ml. 5.5 Inductively coupled plasma Atomic Emission Spectrometer. The instrument shall be equipped with radial plasma as a minimum requirement; axial plasma is equally acceptable.
42、Background correction shall also be performed when necessary. Settings of the working conditions (e.g. viewing height, gas flows, RF or plasma power, sample uptake rate, integration time, and number of replicates) shall be optimised according the manufacturers instructions. 5.6 Freeze drying equipme
43、nt, capable of freeze-drying liquid animal feeding stuffs. 6 Sampling Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in EN ISO 6497 2. It is important that the laboratory receives a sample which is truly representative and has not
44、been damaged or changed during transport or storage. 7 Preparation of the test sample 7.1 General Prepare the test sample in accordance with prEN ISO 6498: The grinding must be done in conditions such that the substance is not appreciably heated and that no contamination takes place by the grinding
45、tools; The operation is to be repeated as many times as is necessary and it must be effected as quickly as possible in order to prevent any gain or loss of constituents (water); The whole ground product is placed in a flask made of e.g. polypropylene, which can be stoppered and stored in such way to
46、 prevent any change in composition; Before any weighing is carried out for the analysis, the whole test sample must be thoroughly mixed for reasons of homogeneity. Since a maximum of 0,5 g of sample is used for the digestion it is of the utmost importance to have a homogeneous sample in order to tak
47、e a representative sub sample. 7.2 Animal feeding stuffs which can be ground as such Grind the laboratory sample (usually 500 g), using a laboratory grinder (0) or mortar, until a particle size of 1 mm or less has been reached. BS EN 15621:2012EN 15621:2012 (E) 8 7.3 Liquid animal feeding stuffs 7.3
48、.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 70 C 5 C during at least 16 h to reduce the moisture content. The mass o
49、f the sample before and after the pre-drying is to be determined using an analytical balance (5.2). Grind the pre-dried sample in accordance with 7.2. 7.3.3 Freeze-drying Freeze-dry the laboratory sample following the instructions of the freeze-drying equipment (5.6). The mass of the sample before and after the freeze-drying is to be determined using an analytical balance (5.2).
