1、BS EN ISO 11490:2016Jewellery Determinationof palladium in palladiumjewellery alloys Gravimetricdetermination withdimethylglyoxime (ISO11490:2015)BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN ISO 11490:2016 BRITISH STANDARDNational forewordThis British Standa
2、rd is the UK implementation of EN ISO 11490:2016. It is identical to ISO 11490:2015. It supersedesBS EN ISO 11490:1995 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee STI/53, Specifications and test methods for jewellery andhorology.A list of organizati
3、ons represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 97
4、8 0 580 74802 8ICS 39.060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2016.Amendments/corrigenda issued since publicationDate Text affectedEUROPEAN S
5、TANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11490 October 2016 ICS 39.060 Supersedes EN ISO 11490:1995English Version Jewellery - Determination of palladium in palladium jewellery alloys - Gravimetric determination with dimethylglyoxime (ISO 11490:2015) Joaillerie - Dosage du palladium dans les a
6、lliages de palladium pour la bijouterie-joaillerie - Dosage gravimtrique par la dimthylglyoxime (ISO 11490:2015) Schmuck - Bestimmung von Palladium in Palladium-Schmucklegierungen - Gravimetrische Bestimmung mit Dimethylglyoxim (ISO 11490:2015) This European Standard was approved by CEN on 26 August
7、 2016. 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 obtain
8、ed 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-
9、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,
10、Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: A
11、venue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11490:2016 EBS EN ISO 11490:2016EN ISO 11490:2016 (E) 3 European foreword The text of ISO 11490:2015 has been prepared by Technical Committee
12、 ISO/TC 174 “Jewellery” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 11490:2016. 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 April 2017, and co
13、nflicting national standards shall be withdrawn at the latest by April 2017. 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 docu
14、ment supersedes EN ISO 11490:1995. 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
15、 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. Endorsement notice The text of ISO 11490:2015 has be
16、en approved by CEN as EN ISO 11490:2016 without any modification. BS EN ISO 11490:2016ISO 11490:2015(E)Contents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Principle 14 Reagents 15 Apparatus . 26 Sampling 27 Procedure. 28 Calculation and expression of results . 38.1 Calculation
17、 38.2 Repeatability . 49 Test report . 4Annex A (informative) Reduction apparatus according to Rose 5Bibliography 6 ISO 2015 All rights reserved iiiBS EN ISO 11490:2016ISO 11490:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bo
18、dies (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 committee. International organizatio
19、ns, 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 document and those intended for its further
20、 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, Part 2 (see www.iso.org/directives)
21、.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 of the document will be in the Introd
22、uction 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 terms and expressions related to con
23、formity 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 Information .The committee responsible for this document is ISO/TC 174, Jewellery.This second edition cancels and replaces the
24、 first edition (ISO 11490:1995), which has been technically revised with the following changes:a) addition of an analytical balance in Clause 5;b) change of requirement for sampling in Clause 6;c) addition of a warning in Clause 7 that suitable health and safety procedures should be followed;d) stan
25、dard editorially revised.iv ISO 2015 All rights reservedBS EN ISO 11490:2016ISO 11490:2015(E)IntroductionThe following definitions apply in understanding how to implement an ISO International Standard and other normative ISO deliverables (TS, PAS, IWA): “shall” indicates a requirement; “should” indi
26、cates a recommendation; “may” is used to indicate that something is permitted; “can” is used to indicate that something is possible, for example, that an organization or individual is able to do something.ISO/IEC Directives, Part 2 (sixth edition, 2011), 3.3.1 defines a requirement as an “expression
27、 in the content of a document conveying criteria to be fulfilled if compliance with the document is to be claimed and from which no deviation is permitted.”ISO/IEC Directives, Part 2 (sixth edition, 2011), 3.3.2 defines a recommendation as an “expression in the content of a document conveying that a
28、mong several possibilities, one is recommended as particularly suitable without mentioning or excluding others, or that a certain course of action is preferred, but not necessarily required, or that (in the negative form) a certain possibility or course of action is deprecated, but not prohibited.”
29、ISO 2015 All rights reserved vBS EN ISO 11490:2016BS EN ISO 11490:2016Jewellery Determination of palladium in palladium jewellery alloys Gravimetric determination with dimethylglyoxime1 ScopeThis International Standard specifies a gravimetric method for the determination of palladium in palladium je
30、wellery alloys, preferably within the range of fineness stated in ISO 9202.These alloys may contain silver, indium, gallium, copper, cobalt, nickel, tin, and ruthenium. Coprecipitated elements have to be determined by a suitable method and a correction applied.2 Normative referencesThe following doc
31、uments, 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 11596, Jewellery Samp
32、ling of precious metal alloys for and in jewellery and associated products3 PrincipleThe sample is dissolved in aqua regia. Palladium is precipitated with dimethylglyoxime. If present, silver is separated as silver chloride. The palladium dimethylglyoxime compound is converted to metallic palladium
33、by ignition and the latter is then determined gravimetrically.4 Reagents4.1 During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity.4.2 Nitric acid (HNO3), approximately 65 % to 70 % HNO3(mass fraction).4.3
34、 Hydrochloric acid (HCl), 30 % to 37 % HCl (mass fraction).4.4 Diluted hydrochloric acid, 8,5 % (mass fraction).4.5 Dimethylglyoxime solution.Dissolve 10 g of dimethylglyoxime in 1 000 ml of ethanol.4.6 Ammonium chloride.4.7 Diluted nitric acid, 1,39 %.Cautiously add 10 ml of nitric acid (4.2) to 1
35、000 ml of water and mix.4.8 Hydrofluoric acid, 40 % (mass fraction).INTERNATIONAL STANDARD ISO 11490:2015(E) ISO 2015 All rights reserved 1BS EN ISO 11490:2016ISO 11490:2015(E)4.9 Diluted sulphuric acid, 50 % (mass fraction).4.10 Reducing gas, such as hydrogen or a hydrogen/nitrogen mixture.4.11 Ine
36、rt gas under pressure, carbon dioxide or nitrogen are usual.4.12 Aqua regia.Mix three volumes of hydrochloric acid (4.3) and one volume of nitric acid (4.2).5 Apparatus5.1 Customary laboratory apparatus.5.2 Reduction apparatus, see Figure A.1.5.3 Platinum dishes, of volume 10 ml.5.4 AAS or ICP-OES,
37、or other means of determining traces of metal.5.5 Muffle furnace, capable of attaining at least 900 C.5.6 Ashless filter paper, capable of retaining particles greater than 3 m.5.7 Analytical balance, with a reading accuracy of 0,01 mg.6 SamplingThe sampling procedure shall be performed in accordance
38、 with ISO 11596.7 ProcedureWARNING Suitable health and safety procedures should be followed.7.1 Flatten the sample to less than 0,5 mm thick and weigh a sample containing 150 mg to 200 mg of palladium accurately to 0,01 mg. Transfer it to an 800 ml tall-form beaker. Add 10 ml of nitric acid (4.2) an
39、d heat at 70 C to 80 C for 20 min in the beaker covered with a watch glass before adding 30 ml of hydrochloric acid (4.3) to complete the dissolution.7.2 If insoluble silver chloride forms, break this up with a glass rod to ensure that all the metal is dissolved.7.3 Remove the watch glass and gently
40、 evaporate to dryness. Dissolve the residue in 10 ml of hydrochloric acid (4.3) and dilute to about 100 ml.7.4 If a precipitate forms, allow it to settle for 12 h in a dark place. Filter and wash with dilute nitric acid (4.7), retaining the precipitate for the determination of traces of palladium us
41、ing suitable apparatus (5.4).7.5 Add 20 ml of hydrochloric acid to the clear solution from 7.3 (or filtrate and washings from 7.4). Dilute to approximately 400 ml, cool to 15 C, and add dimethylglyoxime solution in 5 ml portions up to a total of 30 ml for every expected 100 mg of palladium.2 ISO 201
42、5 All rights reservedBS EN ISO 11490:2016ISO 11490:2015(E)7.6 Leave to settle for 1 h, filter and wash with dimethylglyoxime solution (4.5) diluted 10 times with water. Retain the combined filtrate and washes for determination of palladium using suitable apparatus (5.4) and correct the final result.
43、7.7 Transfer the precipitate and filter to a tared porcelain crucible. Tap the filter to obtain a flat surface and dry in an oven at 110 C to 120 C for 3 h. Cover with a layer of ammonium chloride (4.6) about 3 mm thick (about 4 g for a crucible of diameter 40 mm) to prevent loss of palladium during
44、 ignition.7.8 Heat the crucible gently (for about 40 min) first to char the paper and then to decompose the palladium complex and drive off the ammonium chloride. When all fuming has ceased, ignite at 800 C 50 C for 1 h.NOTE The ammonium chloride decomposes at 340 C.7.9 The partially oxidized pallad
45、ium is reduced to the metallic state by heating in the presence of reducing gas (4.10) and allowing to cool in an inert gas atmosphere (4.11).7.10 Weigh the product to obtain an approximate mass of palladium.7.11 Transfer the impure palladium to a platinum dish (5.3). Moisten with hydrofluoric acid
46、(4.8) and add three drops of dilute sulfuric acid (4.9). Heat until fumes start to evolve from the solution, cool, then extract the residue with a little hot water. Filter and wash with water. Combine the filtrate and washes with those from the previous filtration. Transfer the palladium and filter
47、to a crucible, ignite at approximately 700 C, and reduce as described in 7.9. Reweigh to obtain the final mass.7.12 If contamination of the palladium is suspected, it shall be dissolved in aqua regia (4.12). The elements determined by a spectrometric method and their mass subtracted from the final m
48、ass of palladium, or the palladium, shall be cleaned by repeating the process in 7.1 to 7.11.7.13 The combined filtrates and washes are tested for palladium by instrumental means, usually an AAS or ICP-OES (5.4). Excess dimethylglyoxime is destroyed by evaporation to dryness, then treating the resid
49、ue with aqua regia (4.12). The resulting solution is compared with standard palladium solutions containing equivalent quantities of acids and spectroscopic buffers.8 Calculation and expression of results8.1 CalculationIf the final weighed mass contains exclusively palladium, calculate the palladium content WPdin parts by mass per thousand () using Formula (1).WmmmPd=+321310 (1)wherem1is the mass, in milligrams, of the sample;m2is the mass, in milligrams, in the filtrate;m3is the final mass, in milligrams. ISO 2015 All rights
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