1、BRITISH STANDARDBS EN 14888:2005Fertilizers and liming materials Determination of cadmium contentThe European Standard EN 14888:2005 has the status of a British StandardICS 65.080g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g
2、54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Licensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c) BSIBS EN 14888:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 4 January 2006
3、 BSI 4 January 2006ISBN 0 580 47404 6National forewordThis British Standard is the official English language version of EN 14888:2005.The UK participation in its preparation was entrusted to Technical Committee CII/37, Fertilizers and related chemicals, which has the responsibility to: A list of org
4、anizations represented on this committee can be obtained on request to its secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Corresp
5、ondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of
6、itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and p
7、romulgate them in the UK.Summary of pagesThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 22, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publi
8、cationAmd. No. Date CommentsLicensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c) BSIEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14888August 2005ICS 65.080English versionFertilizers and liming materials - Determination of cadmiumcontentEngrais et amendements minraux
9、 basiques - Dosage ducadmiumDngemittel und Calcium-/Magnesium-Bodenverbesserungsmittel - Bestimmung desCadmiumgehaltesThis European Standard was approved by CEN on 27 June 2005.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this Eu
10、ropeanStandard 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,
11、 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 Rep
12、ublic, 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 STANDARDIZATIONCOMIT EUROPEN DE NORMALISATI
13、ONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14888:2005: ELicensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c
14、) BSIEN 14888:2005 (E) 2 Contents Page Foreword 3 Introduction4 1 Scope .5 2 Normative references .5 3 Terms and definitions.5 4 Principle.5 5 Reagents6 6 Apparatus 7 7 Sampling and sample preparation.7 8 Procedure 8 9 Calculation and expression of the results 10 10 Precision13 11 Test report .15 An
15、nex A (informative) Results of inter-laboratory tests 16 Annex B (informative) Notes on the detection techniques, interferences and quantification19 Bibliography.22 Licensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c) BSIEN 14888:2005 (E) 3 Foreword This document (EN 148
16、88:2005) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is held by DIN. 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 February 2
17、006, and conflicting national standards shall be withdrawn at the latest by February 2006. This European Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association to provide a means of conforming to Essential Requirements of the Regula
18、tion (EC) No 2003/2003 of the European Parliament and of the Council of 13 October 2003 relating to fertilizers. Once this standard is cited in the Official Journal of the European Communities under that Regulation and has been implemented as a national standard in at least one Member State, complia
19、nce with the normative clauses of this standard confers, within the limits of the scope of this standard, a presumption of conformity with the relevant Essential Requirements of that Regulation and associated EFTA regulations. WARNING Other requirements and other EU Directives may be applicable to t
20、he product(s) falling within the scope of this standard. 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, Germ
21、any, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c) BSIEN 14888:2005 (E) 4 Intr
22、oduction Because flame atomic absorption spectrometry (flame AAS) and inductively coupled plasma-optical emission spectrometry (ICP-OES) are widely used techniques for the determination of cadmium, both are described in this European Standard (as method A and method B respectively). Much of the proc
23、edure and many of the reagents are common to both methods. Licensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c) BSIEN 14888:2005 (E) 5 1 Scope This European Standard specifies two methods for the determination of the cadmium content, after extraction with nitric acid, of
24、 solid mineral fertilizers and rock phosphates. It is not applicable to organic and organo-mineral fertilizers. It is applicable to the determination of cadmium contents greater than 1 mg/kg. 2 Normative references The following referenced documents are indispensable for the application of this docu
25、ment. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 1482, Sampling of solid fertilizers and liming materials EN ISO 3696:1995, Water for analytical laboratory use - Specification and
26、test methods (ISO 3696:1987) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 limit of detection smallest measured content from which it is possible to deduce the presence of the analyte with reasonable statistical certainty NOTE The limit of
27、detection is numerically equal to three times the standard deviation of the mean of blank determinations (n 10, where n is the number of measurements). 3.2 limit of quantification lowest content of the analyte which can be measured with reasonable statistical certainty NOTE If both accuracy and prec
28、ision are constant over a concentration range around the limit of detection, then the limit of quantification is numerically equal to ten times the standard deviation of the mean of blank determinations (n 10, where n is the number of measurements). 4 Principle The cadmium is extracted from the fert
29、ilizer by means of a nitric acid digestion. Its concentration is measured either by flame atomic absorption spectrometry (Flame-AAS) (Method A) or by inductively coupled plasmaoptical emission spectrometry (ICP-OES) (Method B). Both methods are relative techniques. Cadmium concentrations are determi
30、ned by the standard addition method. Licensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c) BSIEN 14888:2005 (E) 6 5 Reagents 5.1 General Use only reagents of recognized analytical grade, and water conforming to grade 2 of EN ISO 3696:1995. Stock solutions shall be replace
31、d after a maximum of one year, but the standard solution shall be renewed monthly as a minimum. If a stock solution is prepared directly from a metal, care needs to be taken to ensure that the metal used is free of surface oxide layers. WARNING Cadmium is highly toxic. It is essential that all neces
32、sary measures are taken to avoid ingestion. 5.2 Nitric acid, 65 %, approximately 1,42 g/ml 5.3 Diluted nitric acid, diluted to a concentration of about 7 mol/l (1 + 1 volume fraction). Mix 1 volume of nitric acid (5.2) with 1 volume of water. 5.4 Diluted nitric acid, diluted to a concentration of ab
33、out 4,3 mol/l (1 + 3 volume fraction). Mix 1 volume of nitric acid (5.2) with 3 volumes of water. 5.5 Diluted nitric acid, diluted to a concentration of 2 % (volume fraction). Pipette 20,00 ml nitric acid (5.2) in a 1 000 ml volumetric flask and fill to the mark with water. 5.6 Cadmium stock solutio
34、n, corresponding to 1 000 mg/l. Weigh to the nearest 0,1 mg, approximately 1,000 g of metallic cadmium (minimum purity 99,5 %) and dilute in a covered 250 ml glass beaker with 40 ml of nitric acid (5.4). Then add 100 ml of water. Boil to expel nitrous fumes, cool, transfer to a 1 000 ml volumetric f
35、lask and fill to the mark with water. NOTE Cadmium stock solution of 1 000 mg/l is also readily available commercially, and may be used instead. 5.7 Cadmium standard solution, corresponding to 50 mg/l. Pipette 50,00 ml of the cadmium stock solution (5.6) into a 1 000 ml volumetric flask and fill to
36、the mark with the diluted 2 % nitric acid (5.5). Licensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c) BSIEN 14888:2005 (E) 7 5.8 Cadmium standard solution, corresponding to 1 mg/l. Pipette 20,00 ml of the cadmium standard solution (5.7) into a 1 000 ml volumetric flask a
37、nd fill to the mark with the diluted 2 % nitric acid (5.5). 6 Apparatus 6.1 General Ordinary laboratory glassware. 6.2 Analytical balance, capable of weighing to an accuracy of 0,1 mg. 6.3 Laboratory grinder, capable of grinding to a particle size of less than or equal to 0,5 mm. 6.4 Electric hot pl
38、ate, with temperature control. 6.5 Flame atomic absorption spectrometer The instrument shall be equipped with a cadmium source, a background correction system and a burner suitable for an air/acetylene flame. It shall be operated according to the manufacturers instructions. 6.6 Inductively coupled p
39、lasma Optical emission spectrometer The instrument shall be equipped with radial plasma as a minimum requirement; axial plasma is equally acceptable, as long as it can be shown that the results are statistically equal to the results obtained with radial plasma. Background correction shall also be pe
40、rformed. Settings of the working conditions (e.g. viewing height, gas flows, RF or plasma power, sample uptake rate, integration time, number of replicates) shall be optimized according the manufacturers instructions. 7 Sampling and sample preparation 7.1 Sampling Sampling shall be carried out in ac
41、cordance with EN 1482. 7.2 Sample preparation Grind the laboratory sample, using a grinder or mortar, until a particle size of 0,5 mm or less has been reached, and mix thoroughly for reasons of homogeneity. The grinding shall be done in conditions such that the substance is not appreciably heated. T
42、he operation is to be repeated as many times as is necessary and it shall be effected as quickly as possible in order to prevent any gain or loss of constituents (water, ammonia). Place the whole ground sample in a flask which can be stoppered. Before any weighing is carried out for the analysis, mi
43、x the whole sample thoroughly. Licensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c) BSIEN 14888:2005 (E) 8 7.3 Special cases of grinding Blended fertilizers: in this case, separation frequently occurs. It is therefore essential to grind to a particle size of 0,2 mm or le
44、ss. Products, that decompose on heating: grinding shall be carried out in such a way as to avoid any heating. It is preferable in this case to use a mortar for grinding. 8 Procedure 8.1 Preparation of the test solution 8.1.1 Digestion Weigh to the nearest 0,1 mg an amount of test sample between 1 g
45、and 12,5 g depending on the expected cadmium content (as specified in Table 1), into a beaker or reaction vessel. Moisten the sample with a small amount of water. Add the appropriate amount of nitric acid (5.3), according to Table 1. Cover the beaker with a watch glass and boil gently for 30 min on
46、a hot plate. In order to maintain the initial volume, add some more water during boiling if necessary. Cool, transfer to an appropriate volumetric flask and fill to the mark with water. After homogenizing, filter through a dry filter into a dry container. Use the first portion of the filtrate to rin
47、se the glassware and discard that part. If the determination is not carried out immediately, the container with the filtrate shall be stoppered. The filtrate will be used for the preparation of the final test solution as well as for the preparation of the calibration solutions (8.3). Table 1 Prepara
48、tion of the test portion Expected (declared) content of cadmium in the fertilizer mg/kg 1 to 5 5 to 15 15 to 30 30 to 100 Mass of sample g 12,5 5 2,5 1 Volume of HNO3ml (5.3) 125 50 25 10 Total volume of extract ml 250 250 250 250 Concentration of cadmium in extract mg/l 0,05 to 0,25 0,10 to 0,30 0,
49、15 to 0,30 0,12 to 0,40 NOTE Masses and volumes of the extracts are chosen such that the concentrations in the solutions to be measured are above the typical limits of quantification of flame AAS and ICP-OES, that the concentrations fall within their (linear) working area, and that salt concentrations are not too high. Licensed Copy: Wang Bin, na, Mon Mar 13 06:00:30 GMT 2006, Uncontrolled Copy, (c) BSIEN 14888:2005 (E) 9 8.1.2 Test solution Pipette 50,00 ml of the filtrate of the test portion (8.1.1) into a 100 ml volumetric flask and fill to the mark with the dil
