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© ISO 2015 Jewellery — Determination of palladium in palladium jewellery alloys — Gravimetric determination with dimethylglyoxime Joaillerie — Dosage du palladium dans les alliages de palladium pour l[.]

INTERNATIONAL STANDARD ISO 1 490 Second edition 2015-02-01 Jewellery — Determination of palladium in palladium j ewellery alloys — Gravimetric determination with dimethylglyoxime Joaillerie — Dosage du palladium dans les alliages de palladium pour la bijouterie-joaillerie — Dosage gravimétrique par la diméthylglyoxime Reference number ISO 11490:2015(E) © ISO 2015 ISO 11490:2015(E) COPYRIGHT PROTECTED DOCUMENT © ISO 2015 All rights reserved Unless otherwise specified, no part o f this publication 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 ISO’s member body in the country o f the requester ISO copyright o ffice Case postale 56 • CH-1211 Geneva 20 Tel + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ii © ISO 2015 – All rights reserved ISO 11490:2015(E) Contents Page Foreword iv Introduction v Scope Normative references Principle Reagents Apparatus Sampling Procedure Calculation and expression of results Test report Annex A f Reduction apparatus according to Rose Bibliography 8.1 C alculatio n 8.2 Rep eatab ility (in o rmative) © ISO 2015 – All rights reserved iii ISO 11490:2015(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation o f national standards bodies (ISO member bodies) The work o f 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 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 o f electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular the di fferent approval criteria needed for the di fferent types o f ISO documents should be noted This document was dra fted in accordance with the editorial rules o f the ISO/IEC Directives, Part (see www.iso.org/directives) Attention is drawn to the possibility that some o f the elements o f this document may be the subject o f patent rights ISO shall not be held responsible for identi fying any or all such patent rights Details o f any patent rights identified during the development o f the document will be in the Introduction and/or on the ISO list o f patent declarations received (see www.iso org/patents) Any trade name used in this document is in formation given for the convenience o f users and does not constitute an endorsement For an explanation on the meaning o f ISO specific terms and expressions related to formity assessment, as well as in formation about ISO’s adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword — Supplementary In formation The committee responsible for this document is ISO/TC 174, Jewellery This second edition cancels and replaces the first edition (ISO 11490:1995), which has been technically revised with the following changes: a) addition o f an analytical balance in Clause ; b) change o f requirement for sampling in Clause ; c) addition o f a warning in Clause that suitable health and sa fety procedures should be followed; d) standard editorially revised iv © ISO 2015 – All rights reserved ISO 11490:2015(E) Introduction The 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” indicates 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 something ISO/IEC Directives, Part (sixth edition, 2011), 3.3.1 defines a requirement as an “expression in the content o f a document conveying criteria to be fulfilled i f compliance with the document is to be claimed and from which no deviation is permitted.” ISO/IEC Directives, Part (sixth edition, 2011), 3.3.2 defines a recommendation as an “expression in the content o f a document conveying that among several possibilities, one is recommended as particularly suitable without mentioning or excluding others, or that a certain course o f action is pre ferred, but not necessarily required, or that (in the negative form) a certain possibility or course o f action is deprecated, but not prohibited.” © ISO 2015 – All rights reserved v INTERNATIONAL STANDARD ISO 1 490: 01 (E) Jewellery — Determination of palladium in palladium j ewellery alloys — Gravimetric determination with dimethylglyoxime Scope This I nternationa l Standard s p e ci fie s a gravi me tric me tho d for the de term i nation o f p a l lad iu m i n p a l lad iu m j ewel ler y a l loys , pre ferably with i n the range o f fi nene s s s tate d i n I S O 02 T he s e a l loys may conta i n s i lver, i nd iu m, ga l l ium, copp er, cob a lt, n ickel, ti n, and ruthen iu m C opre cip itate d elements have to b e de term i ne d b y a s u itable me tho d and a corre c tion appl ie d T he Normative references fol lowi ng i nd i s p en s able c u ments , i n whole or i n p ar t, are normatively re ference d i n th i s c u ment a nd are for its For date d re ference s , appl ic ation on ly the e d ition cite d appl ie s For u ndate d re ference s , the late s t e d ition o f the re ference d c u ment (i nclud i ng any amend ments) appl ie s I S O 11 , Jewellery — Sampling of precious metal alloys for and in jewellery and associated products Principle T he s ample i s d i s s olve d i n aqua regia Pa l lad ium i s pre cipitate d with d i me thylglyoxi me I f pre s ent, s i lver i s s ep arate d a s s i lver ch loride T he p a l lad iu m d i me thylglyoxi me comp ou nd i s conver te d to me ta l l ic p a l lad iu m b y ign ition a nd the l atter i s then de term i ne d gravi me tric a l ly 4.1 Reagents D uring the analys is , unles s o therwis e s tated, us e o nly reagents o f reco gnized analytical grade and o nly dis tilled water o r water o f equivalent p urity 4.2 Nitric acid (HNO ) , 4.3 Hydrochloric acid (HCl) , 4.4 Diluted hydrochloric acid , 4.5 Dimethylglyoxime solution ap p roximately % to % H N O % to % H C l (mas s , % (mas s (mas s fractio n) fractio n) fractio n) D i s s olve 10 g o f d i me thylglyoxi me i n 0 m l o f e th anol 4.6 Ammonium chloride 4.7 Diluted nitric acid , ,3 % 4.2 C autiou s ly add 10 m l o f n itric ac id ( 4.8 ) to 0 m l o f water and m i x Hydrofluoric acid, 40 % (mas s fractio n) © ISO 2015 – All rights reserved ISO 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 Inert gas under pressure, carbon dioxide or nitrogen are usual 4.12 Aqua regia Mix three volumes o f hydrochloric acid (4.3 ) and one volume o f nitric acid (4.2) Apparatus 5.1 Customary laboratory apparatus 5.2 Reduction apparatus , see 5.3 Platinum dishes , o f volume 10 ml 5.4 AAS 5.5 M u fle As hles s filter p ap er 5.7 Analytical balance , with a reading accuracy o f 0,01 f Figure A.1 or ICP-OES, or other means o f determining traces o f metal furnace , capable o f attaining at least 900 °C , capable o f retaining particles greater than μm mg Sampling The sampling procedure shall be per formed in accordance with ISO 11596 Procedure WARNING — Suitable health and safety procedures should be followed Flatten the sample to less than 0,5 mm thick and weigh a sample containing 150 mg to 200 mg o f palladium accurately to 0,01 mg Trans fer it to an 800 ml tall- form beaker Add 10 ml o f nitric acid (4.2) and heat at 70 °C to 80 °C for 20 in the beaker covered with a watch glass be fore adding 30 ml o f hydrochloric acid (4.3) to complete the dissolution 7.1 7.2 I f insoluble silver chloride forms, break this up with a glass rod to ensure that all the metal is dissolved Remove the watch glass and gently evaporate to dryness Dissolve the residue in 10 ml o f hydrochloric acid (4.3 ) and dilute to about 100 ml 7.3 7.4 I f 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 o f traces o f palladium using suitable apparatus (5.4) Add 20 ml o f 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 ml portions up to a total o f 30 ml for every expected 100 mg o f palladium 7.5 © ISO 2015 – All rights reserved ISO 11490:2015(E) 7.6 Leave to s ettle fo r h, filter and was h with dimethylglyoxime s o lutio n ( water Retain the co mb ined filtrate and was hes (5.4 fo r 4.5) diluted 10 times with determinatio n o f p alladium us ing s uitab le ap p aratus ) and co rrect the final res ult 7.7 Trans fer the p recip itate and filter to a tared p o rcelain crucib le Tap the filter to o b tain a flat s ur face and dry in an oven at 1 °C to °C thick (ab o ut g 7.8 fo r fo r h C over with a layer o f ammo nium chlo ride (4 ) ab o ut mm a crucib le o f diameter 40 mm) to p revent lo s s o f p alladium during ignitio n H eat the crucib le gently ( fo r ab o ut 40 min) firs t to char the p ap er and then to deco mp o s e the p alladium co mp lex and drive o ff the ammo nium chlo ride When all ± °C NO TE 7.9 fo r fuming has ceas ed, ignite at 0 °C h T he a m mo n iu m ch lo r ide de co mp o s e s at ° C The p artially oxidized p alladium is reduced to the metallic s tate by heating in the p res ence o f reducing gas ( 4.10 ) and allo wing to co o l in an inert gas atmo s p here ( 4.11) 7.10 Weigh the p ro duct to o b tain an ap p roximate mas s o f p alladium 7.11 Trans fer the imp ure p alladium to a p latinum dis h ( add three dro p s o f dilute s ul furic acid ( 4.9 5.3 fumes ) H eat until ) M o is ten with hydro fluo ric acid ( s tart to evo lve fro m 4.8 ) and the s o lutio n, co o l, then extract the res idue with a little ho t water Filter and was h with water C o mb ine the filtrate and was hes with tho s e fro m the p revio us filtratio n Trans fer the p alladium and filter to a crucib le, ignite at ap p roximately 0 °C , and reduce as des crib ed in 7.12 7.9 Reweigh to o b tain the final mas s I f co ntaminatio n o f the p alladium is s us p ected, it s hall b e dis s o lved in aqua regia ( determined by a s p ectro metric metho d and their mas s s ub tracted p alladium, s hall b e cleaned by rep eating the p ro ces s in 7.13 The co mb ined filtrates and was hes are tes ted AAS or ICP-OES (5.4 fro m 7.1 to 7.11 fo r 4.12) The elements the final mas s o f p alladium, o r the p alladium by ins trumental means , us ually an ) E xces s dimethylglyoxime is des troyed by evap o ratio n to drynes s , then treating the res idue with aqua regia ( 4.12 ) The res ulting s o lutio n is co mp ared with s tandard p alladium s o lutio ns co ntaining equivalent quantities o f acids and s p ectro s co p ic b u ffers Calculation and expression of results 8.1 Calculation I f the fi na l weighe d ma s s contai n s exclu s ively p a l l ad iu m, c a lc u l ate the p a l l ad iu m content WPd i n p ar ts b y mas s p er thou s and (‰) u s i ng Formu l a (1) WPd = m3m+ m2 × 10 where m1 m2 m3 (1) i s the ma s s , i n m i l l igra m s , o f the s ample; i s the ma s s , i n m i l l igra m s , i n the fi ltrate; i s the fi na l mas s , i n m i l l igram s © ISO 2015 – All rights reserved ISO 11490:2015(E) I f the fi na l weighe d ma s s contai n s o ther elements , c a lc u l ate the p a l l ad iu m content WPd i n p ar ts b y ma s s p er thou s and (‰) u s i ng Formu la (2 ) WPd = m3 + mm2 − m x × 10 where mx (2) i s the to ta l ma s s , i n m i l l igra m s , o f o ther elements T he p a l l ad iu m content WPd i n p a r ts b y mas s p er thou s and (‰) i s corre c te d i n the s i lver ch loride pre c ipitate d i n WPd = m3 + m2m− m x + m y × 10 8.2 for the mas s my o f p a l lad iu m u s i ng Formu la (3 ) (3) where my 7.4 i s the mas s , i n m i l l igram s , o f p a l l ad iu m i n the s i lver ch loride Repeatability T he re s u lts o f dupl ic ate de term i nation s sha l l corre s p ond to b e tter tha n five p ar ts p er mas s p er thou s and (‰) o f p a l lad ium I f the vari ation i s gre ater tha n th i s , the a s s ays sh a l l b e rep e ate d Test report T he te s t rep or t sh a l l i nclude the fol lowi ng i n formation: a) identi fic ation o f the s ample i nclud i ng s ou rce, date o f re ceip t, b) s ampl i ng pro ce dure; c) the me tho d u s e d b y re ference to th i s I nternationa l Sta nda rd , i e I S O 149 ; d) p al ladium content o f the s ample, in p arts by mas s p er thous and (‰) , as s ingle values and mean values; e) i f relevant, any devi ation s f) any unu s ua l g) date o f te s t; h) identi fic ation o f the lab orator y c a rr yi ng out th i s ana lys i s; i) s ignatu re o f the lab orator y manager and op erator fe atu re s from form o f s a mple; the me tho d s p e ci fie d i n th i s I nternationa l Sta nda rd; ob s er ve d du ri ng the de term i nation; © ISO 2015 – All rights reserved ISO 11490:2015(E) Annex A (in fo rmative) Reduction apparatus according to Rose Key lidded Rose crucible gas flow gas b urner Figure A.1 — Reduction apparatus © ISO 2015 – All rights reserved ISO 1 49 0: 01 (E) Bibliography [1] I S O 2 : 19 , Jewellery — Fineness of precious metal alloys © ISO 2015 – All rights reserved ISO 1 490: 01 (E) I CS   9.0 60 Price based on pages © ISO 2015 – All rights reserved

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