1、BS ISO 21033:2016Animal and vegetable fatsand oils Determination oftrace elements by inductivelycoupled plasma opticalemission spectroscopy (ICP-OES)BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 21033:2016 BRITISH STANDARDNational forewordThis British Standa
2、rd is the UK implementation of ISO 21033:2016. It supersedes PD ISO/TS 21033:2011+A1:2012 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee AW/307, Oilseeds, animal and vegetable fats and oils and their by-products.A list of organizations represented on
3、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 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 87010 1
4、ICS 67.200.10 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 31 May 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 21033:
5、2016 ISO 2016Animal and vegetable fats and oils Determination of trace elements by inductively coupled plasma optical emission spectroscopy (ICP-OES)Corps gras dorigines animale et vgtale Dtermination des lments traces dans les corps gras par spectromtrie dmission optique plasma induit par haute frq
6、uence (ICP-OES)INTERNATIONAL STANDARDISO21033First edition2016-05-15Reference numberISO 21033:2016(E)BS ISO 21033:2016ISO 21033:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this public
7、ation may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the countr
8、y of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 21033:2016ISO 21033:2016(E)Foreword .iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Reagents
9、 26 Apparatus . 27 Sampling 28 Preparation of test sample . 39 Procedure. 39.1 General . 39.2 Preparation of standards 49.2.1 Blank . 49.2.2 Standards 49.3 Standardization 49.4 Preparation of samples 510 Calculation 511 Precision . 511.1 Interlaboratory test. 511.2 Repeatability . 511.3 Reproducibil
10、ity . 512 Test report . 5Annex A (informative) Results of interlaboratory studies . 7Annex B (informative) Additional data .11Bibliography .13 ISO 2016 All rights reserved iiiContents PageBS ISO 21033:2016ISO 21033:2016(E)ForewordISO (the International Organization for Standardization) is a worldwid
11、e federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that
12、 committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this docume
13、nt and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives
14、, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development
15、of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific
16、 terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 34, Food products, Subc
17、ommittee SC 11, Animal and vegetable fats and oils.This first edition cancels and replaces ISO/TS 21033:2011, which has been technically revised. It also incorporates the Amendment ISO/TS 21033:2011/Amd 1:2012. The scope has been revised to state that the document is not applicable to milk and milk
18、fat products.iv ISO 2016 All rights reservedBS ISO 21033:2016INTERNATIONAL STANDARD ISO 21033:2016(E)Animal and vegetable fats and oils Determination of trace elements by inductively coupled plasma optical emission spectroscopy (ICP-OES)1 ScopeThis International Standard specifies an inductively cou
19、pled plasma optical emission spectroscopic method (ICP-OES) for the determination of the trace element content in oils. Depending on the dilution solvent used, most types of vegetable oils can be analysed (crude, degummed, refined, bleached, deodorized and hardened oils) and nearly all types of leci
20、thins and phosphatides. Milk and milk products (or fat coming from milk and milk products) are excluded from the scope of this International Standard.This method is only suitable when the elements are present in a solubilized form. Fine particles, such as bleaching earth, metal particles and rust, c
21、an result in poor recovery of the trace elements present as nebulization and atomization problems affect the ICP-OES analysis.NOTE The only suitable non-ashing direct method for samples containing fine particles is graphite furnace atomic absorption spectrometry.2 Normative referencesThe following d
22、ocuments, 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.ISO 661, Animal and veg
23、etable fats and oils Preparation of test sampleISO 6353-2, Reagents for chemical analysis Part 2: Specifications First seriesISO 6353-3, Reagents for chemical analysis Part 3: Specifications Second series3 Terms and definitionsFor the purposes of this document, the following terms and definitions ap
24、ply.3.1trace elementelement present in very low concentrationsNote 1 to entry: Trace element content is expressed as a mass fraction in milligrams per kilogram.4 PrincipleSolvent-diluted vegetable oils are analysed for trace elements by direct aspiration. Liquid samples are nebulized and carried int
25、o the excitation source by a flowing gas. Atoms are quantified by measuring the specific emission lines produced by atoms decaying from high energy levels. ISO 2016 All rights reserved 1BS ISO 21033:2016ISO 21033:2016(E)5 ReagentsWARNING Attention is drawn to national regulations that specify the ha
26、ndling of hazardous substances and users obligations thereunder. Technical, organizational and personal safety measures shall be followed.Unless stated otherwise, use reagents specified in ISO 6353-2 and ISO 6353-3, if listed there; if not, then use reagents of recognized analytical grade.5.1 1-Buta
27、nol, ISO 6353-3.5.2 Kerosene.5.3 Xylene, ISO 6353-3.5.4 Standard elements, present in solution as an organic soluble material.1)Multi-element standards may be used.5.5 Base oil,2)may be used to check the blank oil used and for the dilution of the standard solutions as needed.5.6 Blank oil, typically
28、, refined and bleached soya bean or other oil, which has been shown to be free of trace elements.5.7 Mixture of the blank oil (5.6) with 1-butanol (5.1), mass fraction w(blank oil)= 50 g/100 g.6 ApparatusUsual laboratory equipment and, in particular, the following.6.1 Inductively coupled plasma opti
29、cal emission spectrometer.6.2 Analytical balance, readability 0,000 1 g, weighing precision 0,001 g.6.3 Oven, capable of maintaining a temperature of (60 2) C.6.4 Tilt table mixer.6.5 Volumetric flasks, capacity 100 ml.7 SamplingSampling is not part of the method specified in this International Stan
30、dard. A recommended sampling method is given in ISO 5555.1It is important that the laboratory receive a truly representative sample which has not been damaged or changed during transport or storage.1) SPEX products are examples of suitable products available commercially. This information is given f
31、or the convenience of users of this document and does not constitute an endorsement by ISO of these products.2) Base 20 Oil or Base 75 Oil from Accu-Standard are examples of suitable products available commercially. This information is given for the convenience of users of this document and does not
32、 constitute an endorsement by ISO of these products.2 ISO 2016 All rights reservedBS ISO 21033:2016ISO 21033:2016(E)8 Preparation of test samplePrepare the test samples in accordance with ISO 661, except that the samples should not be clarified.9 Procedure9.1 General9.1.1 Melt solid samples at appro
33、ximately 10 C above their melting point and homogenize prior to dilution. Keep the diluted sample warm and monitor throughout the analysis to ensure it remains in solution. The maximum temperature for the analysis of hardened fats is 60 C.9.1.2 All samples, standards and blanks are diluted (equal vo
34、lume fractions) with 1-butanol (kerosene or xylene) to reduce the viscosity of the oil for better nebulization. Some samples are more soluble in 1-butanol than others.1-Butanol is preferred because it has better moisture tolerance and allows a higher flow rate with higher pressure than kerosene with
35、out extinguishing the torch. The increased moisture tolerance permits the analysis of crude oils and lecithins without phase separation. The higher flow rate provides for improved detection limits.If kerosene or xylene is used, all instrumental operating conditions, e.g. pump flow rate, change from
36、those set for 1-butanol. Therefore, the analysis shall be standardized and all analyses shall be run with all standards, blank and samples dissolved in the same solvent.9.1.3 The instrument is ignited and allowed to warm. Profile the instrument according to the manufacturers instructions. Elements c
37、an be detected at the major emission lines (see Table 1). Additional emission lines and equipment set-up instructions are given in EN 145385and ISO 10540-3.4Table 1 Major emission lines and limits of detectionElementCurrent limits of detection mg/kgMajor emission line(s) nmAluminium a167,078 308,215
38、Barium a455,404Boron a249,773Cadmium a226,502 214,441 228,802Calcium 0,05 315,887 393,366 317,933Chrome a267,716 284,325 283,563Copper 0,05 324,754 327, 396Iron 0,05 259,940 238,204 261,187Lead a220,353Magnesium 0,05 285,213 279,553 280,270Manganese a257,611 259,373Molybdenum a281,615 202,095Nickel
39、0,05 231,604 221,648 341,476Phosphorus 0,05 213,618 178,287 177,495Silicon 0,1 251,611 288,158Silver a328,068Sodium 0,1 588,995aNot reported at the time of publication. ISO 2016 All rights reserved 3BS ISO 21033:2016ISO 21033:2016(E)ElementCurrent limits of detection mg/kgMajor emission line(s) nmSu
40、lfur 1 180,731Tin a242,949Titanium a334,941 323,452 336,121Vanadium a309,311 311,071Zinc a202,613 213,856aNot reported at the time of publication.9.1.4 Standardize the instrument as specified in 9.3 and scan all the samples in triplicate.NOTE Calibration drift has been noted. It can result from carb
41、on build-up on the injector tip.9.2 Preparation of standards9.2.1 BlankTypically, refined and bleached soya bean or other oil, which has been shown to be free of trace elements, is used. Blank oil is diluted (1:1) as described in the sampling procedure. Base oil (5.5) is used as an absolute referenc
42、e blank to determine that the blank oil is free of trace elements.9.2.2 StandardsThe standard is prepared from commercially available single element organic-based standards. Weigh accurately the standard and add enough blank oil to total 50,00 g. Add 50,00 g of solvent (1-butanol, kerosene or xylene
43、) to achieve a (1:1) dilution.One standard concentration works; however, up to four multi-level, multi-element standards provide a better calibration for linearity and accuracy. Levels should include 2,5 mg/kg, 5 mg/kg and 10 mg/kg standards depending on the range of values expected.Instruments that
44、 are capable of simultaneous detection of multiple elements can achieve improved precision and accuracy by the inclusion of an internal standard in the analysis. If an internal standard is used, it should be incorporated as part of the dilution step. Typically, the resultant dilution should contain
45、10 mg/kg yttrium or scandium. Thus, under the dilution sequence for sampling (see 9.1.1 and 9.4), the diluent should contain 20 mg/kg internal standard yielding 10 mg/kg yttrium or scandium in the 1:1 dilution to accomplish this.9.3 StandardizationRun the blank oil standard and diluted base oil (5.5
46、) at the specified wavelength for the element(s) of interest.Run the standard solutions (see 9.2.2) at the wavelength(s) chosen.Blanks, samples and standards are scanned in triplicate for trace element(s) and are averaged.Standards and the blank are run every 10 samples or fewer and the instrument i
47、s re-standardized as needed. For accuracy, use a narrow range of standardization (0 mg/kg to 25 mg/kg of each element). Although the linearity is somewhat greater, test samples should be diluted to keep the trace element(s) content within the range of standardization.Table 1 (continued)4 ISO 2016 Al
48、l rights reservedBS ISO 21033:2016ISO 21033:2016(E)9.4 Preparation of samplesWeigh 2,5 g 0,02 g of sample into an auto-sampler tube and dilute with 2,5 g of 1-butanol (kerosene or xylene) delivered from an automatic pipette. Cap the tube and invert 40 times to 50 times on a mixing table.Dilute 0,2 g
49、 lecithins (up to 100 % acetone insoluble) to 5,0 g with blank soybean oil (dilution factor 25) and then to 10 g with 1-butanol (5.6), dilution factor 50. Mix the samples on a tilt table mixer for 1 h. Then dilute 1 part with 10 parts of the mixture of the blank oil and 1-butanol (5.7). The total dilution factor is 500.10 CalculationComputation is a feature of most instrument programs. Area counts from known standards are inserted into a linear regression formula versus the sample concentration. Fr
