Hofmans LBMA presentation 3-2009 final.ppt · Due to the difficulty in its production and value...

The LBMA Assaying & Refining Seminar, 24-25 March 2009 1

A survey of Available Reference MaterialsDirk HofmansAnalytical laboratoryUmicore HobokenBelgium

Summary:

Definition of a “Reference material”

Who provides Certified Reference Materials?

The Need for (Certified) Reference Materials

Methods applied for Ag and Au 4NMethods applied for Ag and Au 4N

Suppliers of Certified Reference Materials

Suppliers of Reference Materials

Conclusion


Reference Material: DefinitionReference Material (RM) Material or substance one or more of whose propertyReference Material (RM) - Material or substance one or more of whose property values are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessment of a measurement method, or for assigning values to materials. (ISO VIM: 1993)

Certified Reference Material (CRM) - Reference material, accompanied by a certificate, one or more of whose property values are certified by a procedure which establishes traceability to an accurate realization of the unit in which the property values are expressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence. (ISO International Vocabulary of Basic and General Terms in Metrology (VIM): 1993)

Reference Material Certificate - Document accompanying a certified reference material stating one or more property values and their uncertainties, and confirming that the necessary procedures have been carried out to ensure their validity and traceability. (ISO Guide 30: 1992)

Who provides CRM?⇒ CRMs are cornerstones of modern analytical quality assurance because⇒ CRMs are cornerstones of modern analytical quality assurance because they allow calibration of instruments, validation of methods, and quality control of methods and laboratories based on traceability and comparability of measurement results.

Due to the difficulty in its production and value assignment (ISO17025),CRMs are usually produced by national or international metrology institutes like NIST (USA), BAM (Germany), KRISS (Korea) and IRMM (European Commission).

However… today NIST, BAM, KRISS or IRMM have no “metallic” (C)RMs for Ag and Au in their catalogue.Focus on pollutants, food and drug, or metals as Cu (e.g. BCR-074), Zn (e.g. BCR-326) and Pb (e.g. BCR-288) and some alloys.


The need for (C)RM1 An up to date analytical laboratory works according to the rules of Good1. An up-to-date analytical laboratory works according to the rules of Good Laboratory Practice (GLP) or ISO:

• a framework within which laboratory studies are planned, performed, monitored, recorded, reported and archived.

• assures regulatory authorities that the data submitted are a true reflection of the results obtained during the study

(C)RM are a indispensable tool in monitoring the accuracy of a laboratory.

2. A laboratory can be “invited” to proof it’s performance by • participating Round Robins• pro-active monitoring (e.g.LBMA)• local / international regulation (e.g. Hallmarking, no final EU regulation yet!).

(C)RM are also indispensable as a QC monitor in this case.

The need for (C)RM3 Continous monitoring is the only guarantee for constant quality:3. Continous monitoring is the only guarantee for constant quality:Weak point with Round Robin or pro-active monitoring:

• Samples are not “blind” : extra attention is given for optimum performance• Different methods are applied compared to the analysis for standard production lots.• Material have to be analysed out of the normal scope of the laboratory

(e.g. Au 99.5% while only 99.99+ Au production)

=> Benchmarking to (certified) material is crucial for permanent quality assurance


Methods applied for Ag 4N(survey amongst Ag and Au LBMA RM buyers)

Methods applied:

Standards used:Methods in solution:

•Solutions with certificate for calibration curve at all labs•Updating calibration curves with standards obtained from CRM solutions

Feedback from the laboratories 19methods applied by difference 22

direct titration 1method type on solution ICP-OES / MS 11

AAS 2DC Arc 1total 14

method type on solid state Spark Ablation ICP-OES 1Spark Source OES 7total 8

g•Reference material is easy to obtain

Methods on the solid state:•4 labs use (C)RM for the calibration curve, all labs prepare own RM for QC check•accuracy of procedure is checked by other methods (ICP) or by a Round Robin• (C)RM are hard to get (long waiting time)

Methods applied for Au 4N(survey amongst Ag and Au LBMA RM buyers)

Methods applied:

Standards used:Methods in solution:

•Solutions with certificate for calibration curve at all labs•Updating calibration curves with standards obtained from CRM solutions

Feedback from the laboratories 17methods applied by difference 18

fire assay 2method type on solution ICP-OES / MS 8

AAS 1DC Arc 1total 10

method type on solid state Spark Ablation ICP-OES 1Spark Source OES 7total 8

g•Reference material is easy to obtain

Methods on the solid state:•4 labs use (C)RM for the calibration curve, all labs prepare own RM for QC check•accuracy of procedure is checked by other methods (ICP) or by a Round Robin•Solid RM also used by 2 labs working by wet chemical methods


Suppliers for (Certified) Reference MaterialsOnly a limited number of suppliers for Ag and Au (Certified) Reference MaterialsOnly a limited number of suppliers for Ag and Au (Certified) Reference Materials.

Sources: Comar => http://www.comar.bam.de/en/ , personal contacts & Google

This presentation • is not meant to be an advertisement or promotion of the supplier or

representative.• tries to make an overview of what is available on the market.• may not be complete! y p• doesn’t guarantee the quality, response time or solvability of the

representative or the supplier

• Umicore doesn’t have any interest in these companies.• Umicore and the LBMA cannot be held responsible for decisions taken based upon

this list of suppliers / representatives.

Suppliers for Certified Reference Materials:P li h Mi t / IMN Poland htt // i lPolish Mint / IMN Poland http://www.mennica.com.pl

WarsawPolandContact person: Pawel Bielski ([email protected])

Sells Au Certified Reference Material for XRF spectrometry• Suited for Au alloys• Collaboration with the Institute of Non-Ferrous Metals (IMN) Gliwice Poland• Collaboration with the Institute of Non Ferrous Metals (IMN), Gliwice, Poland• The department IMN is accredited: No AB PN-EN ISO/IEC 17025• Typical for XRF: discs (30 mm diameter, thin layer on aluminium mount)• Certified by Flame AAS, ICP, gravimetry, fire assay,titration,...• 10 labs are involved with the certification procedure (2 from Poland, 8 from

abroad including RCM, Rand Refinery, Metalor USA).


Suppliers for Certified Reference Materials:P li h Mi t / IMN PolandPolish Mint / IMN Poland

The Au CRM standards for XRF (summary, results in %)

Suppliers for Certified Reference Materials:Institute of Non Ferrous Metals http //en imn gli ice pl/K alamiInstitute of Non-Ferrous Metals http://en.imn.gliwice.pl/Kyalami

GliwicePolandContact person: Ewa Muller

Produces and sells Precious Metal Certified Reference Materials for Ag• The department IMN is accredited: No AB PN-EN ISO/IEC 17025• The Ag SH series standards can be sold as a set or as individual samples and isThe Ag SH series standards can be sold as a set or as individual samples and is

available.• For Optical Emission Spectrometry (eg spark,GD): discs (40mm x 15-20 mm)• Assay carried out in 2 labs in Poland, Birmingham Assay Office (UK), ARL (CH)


Suppliers for Certified Reference Materials:IMN PolandIMN, PolandThe Ag SH CRM series

No. Element SH 1 SH2 SH 3 SH4

Cu 309 182 59,0 12,3 Fe 19,9 13,5 11,3 28,5 Pb 2,6 26,0 44,9 81,1 Zn 2,9 22,3 43,8 95,9 Sb 1,6 25,1 48,6 80,0 Bi 44,9 28,2 9,2 1,4 Ni 1,9 12,5 29,7 51,4 Se 47,6 27,4 8,7 1,1 Te 0 95 8 6 25 7 42 3Te 0,95 8,6 25,7 42,3As 46,5 27,2 11,0 1,8 Pd 1,6 8,5 25,7 42,6 Au 38,9 23,2 7,7 1,7 Pt 1,1 9,5 25,4 42,7 Cd 29,7 23,3 9,6 2,2 Mn 1,1 82,1 27,3 45,3 In 49,2 30,3 8,7 (1,3) Tl 0,89 9,3 25,8 42,4 Ag The rest The rest The rest The rest

Suppliers for Certified Reference Materials:JSC Krastsvetmet http // krasts etmet com/di ision/prokat/JSC Krastsvetmet http://www.krastsvetmet.com/division/prokat/

Krasnoyarsk Russian FederationContact person: V. Shukhovtsev

Sells Au Certified Reference Materials, concentration typical for XRF spectrometry • Au alloys with Ag, Au, Cu or Sn certificate• The State Reference Standards are CRM• The Internal Reference Materials are CRM, some are present under metrological , p g

checking by the State System of Standardization.• The solid reference materials are available as shavings (< 1mm), rolled, as wire,

blocks and discs• Website with pictures of PM reference materials production

http://www.krastsvetmet.com/division/43/standardsamples/


Suppliers for Certified Reference Materials:JSC Krastsvetmet: Au CRM standards (part of the list source: website)JSC Krastsvetmet: Au CRM standards (part of the list, source: website)

Chemical Composition of Gold Alloy GSO

GSO No. Gold Content, % Silver Content, % Copper Content, %

GSO 8754-2006 0,11 0,49 99,40

GSO 8755-2006 0,49 1,93 97,58

GSO 8756-2006 1,97 4,90 93,13

GSO 8757-2006 4,95 9,86 85,19

GSO 8758-2006 10,05 79,87 10,08

GSO 8759-2006 29,94 29,90 40,16

GSO 8760-2006 50,02 49,80 0,18

GSO 8761-2006 79,88 20,0 0,12

GSO 8762-2006 89,91 5,07 5,02

GSO 8763-2006 98,97 0,10 0,93

Gold Alloy GSO samples can be manufactured as wire of 1 mm diameter; sheet segments of 0.3 – 0.4 mm thickness, 20, 30,40 mm wide; disks of 0.3-0.4 mm. GSOs as chips are supplied with weight not less than 10 g.

Suppliers for Reference Materials:Industrial Analytical Ltd http://www industrialanalytical co za/IA swfIndustrial Analytical Ltd http://www.industrialanalytical.co.za/IA.swfKyalamiSouth AfricaContact person: Francois Beukes, Managing director

Marketing and selling agent for Precious Metal reference Materials• RM produced by Rand Refinery, SA• No stock items, but list of PMRs available as guideline

• Standards will be prepared in accordance to the technique (XRF OESM ICP )• Standards will be prepared in accordance to the technique (XRF, OESM, ICP..)• typical for XRF: discs (24mm x 4 mm in mount)• for AAS/ICP in globule form• for OESM as solid discs 25mm x 10mm. Size can vary upon request.

• Concentration levels of impurities in agreement with the client (and according to technical possibilities)

• Each RM is supplied with a certificate of analysis stating that “RM has analysed this material to the best of its ability”


Suppliers for Reference Materials:Industrial Analytical LtdIndustrial Analytical Ltd

Examples ( “the impurity concentrations will be certified and will fall within 20%of the specific values” & “impurities will be reported as found present”)

Suppliers for Reference Materials:Industrial Analytical Ltd : Au RM Certificate by Rand RefineryIndustrial Analytical Ltd : Au RM Certificate by Rand Refinery


Suppliers for Reference Materials:MBH http // mbh co k/inde htmMBH http://www.mbh.co.uk/index.htm

BarnetUK + local distributers worldwideContact person: Chris Eveleigh, Technical director

Member of ASTM E01 technical committe for analysis of metals & subcommittee for precious metals

• Sells Au RM produced by Rand Refinery, SA• No stock items, the list of PMRs available in catalogue is a guideline• Works with local suppliers for Ag RM + assays at Assay Offices in the UK.• MBH provides

• RM suited for XRF (3mm thick, embedded in Bakelite)• RM for use with OESM (34mm diameter)• Continuous cast bars upon request and to customer’s requirements

Suppliers for Reference Materials:MBH : Ag RM (examples)MBH : Ag RM (examples)

Made against a customer’s request, 25mm x 3mm in Bakelite mount, for XRF. Analysed by Birmingham Assay Office.

Silver with ImpuritiesCu Pb Bi Zn As Sb Se Hg Au Sn Ir Pt Pd Fe Te Mn

131X AGP1 A 522 465 485 312 308 465 287 <1 529 489 <1 514 517 150 483 242131X AGP2 A 137 112 113 77 48 93 68 <1 138 129 <1 127 130 73 121 20131X AGP3 A 44 31 29 20 19 24 17 <1 36 26 <1 32 32 46 30 12131X AGP4 A 20 5 6 7 5 6 <1 <1 10 <1 <1 10 8 24 7 2

All Elements ppm

Bigger standards, made by continuous casting of a 10 Kg melt. 1m bar, 34mm diameter. For OESM.Impurities analysed by 3 laboratories, including wet chem and XRF from Sheffield Assay Office.

Silver with ImpuritiesCu Pb Bi Zn As Sb Se Hg Au Sn Ir Pt Pd Fe Te Mn Ni Cd Ga Si

131X PAg1 A 75 40 40 50 12 50 35 . . . . 120 40 <1 35 180 5 120 35 25 35 60 30131X PAg2 A 400 12 12 550 8 12 10 . . . . 20 14 <1 10 180 7 15 10 9 5 15 4

All Elements ppm


Suppliers for Reference Materials:Great Wall Gold & Silver Refinery http://www cdccgold comGreat Wall Gold & Silver Refinery http://www.cdccgold.comChengduChinaContact person: Dr Jie Chen

• Produces Ag and Au RM (2 sets 2002-2007)• Au RM: 12 impurities, set of 6 standards (total 650g)• Ag RM: 10 impurities, set of 6 standards (total 380g)

• Form: stick of 6mm x 100 mm• Prepared from Au and Ag 5x9 and 4X9. Quality impurities added >99.9%• Analysed by ICP-AES, ICP-MS, GFAAS / FAAS by 6 different laboratories in

China.• Homogeneity test & calculation acc test GB/T15000.5-1994 (China Association

for Standardization). • Certificates are issued by the People’s Bank of China

Suppliers for Reference Materials:Great Wall Gold & Silver RefineryGreat Wall Gold & Silver Refinery

• E.g. Au Certificate has values for Ag, Cu, Fe, Pb, Sb, Bi, Pd, Mg, Sn, Cr, Ni & MnPart of the Certified Values & Uncertainties of Au RM (ppm)

1 2 3 4 5 6Certified Values 3.2 16 33 75 176 407

Uncertainties 0.3 0.4 0.9 2.3 5.7 10.5

Certified Values 1.9 11 28 67 162 383

Uncertainties 0.2 0.2 0.5 1.4 4.4 6.7


Uncertainties 0.9 1 1.5 3 2.2 4.8

Certified Values 4 13 34 78 159 332

Ag

Cu

FeCertified Values 4 13 34 78 159 332

Uncertainties 0.1 0.1 0.4 0.6 2.9 6.1

Certified Values 2.2 6.8 17 34 68 151

Uncertainties 0.2 0.6 1.6 2.2 5 8

Certified Values 3.2 9.8 21 42 82 165

Uncertainties 0.1 0.5 0.8 0.9 1.7 2.1


Uncertainties 0.1 0.2 0.3 1.2 2.3 4.7

Sb

Bi

Pd

Pb


Suppliers for Reference Materials:Spex Certiprep http://www spexcertiprep co uk/Spex Certiprep http://www.spexcertiprep.co.uk/Middlesex, UK Contact person: Nadia Somauroo

• Reseller of RM• Can provide standards for XRF, OES.• Works with suppliers from South Africa, China, Poland and others.• Availability from 2-3 weeks (stock) to 3-6 month (special requests)• Examples on the website

MetalorNeuchâtel, CHSwitzerland Contact person: Paul Bagnoud

• Produces and analyses reference materials for Ag and Au upon request.

Conclusion:• Over 90% of the laboratories involved with Ag or Au 4N assay determine• Over 90% of the laboratories involved with Ag or Au 4N assay determine

the quality of the metal by difference (*).• About 50% of the laboratories work on dissolved metal and use CRM

solutions for their calibration curves.• About 50% of the laboratories work on the metal, without dissolution,

mainly by Spark Source OES.• About 50% of these laboratories use Reference Material to calibrate or verify their

calibration curves.• All these laboratories have home made reference materials for daily businessy• Only a few suppliers provide solid state RM for Ag and Au 4N matrices. Most of

these set are also customer build and require a long time to prepare.• Only a few suppliers are certified to produce CRM for Ag and Au 4N.• The study and feed-back confirm that there is a great need for Ag an Au RM, a

need that will be covered by the Ag and Au RM from the LBMA.

(*) based upon the feedback on the survey organized within the LBMA


Thank You

Hofmans LBMA presentation 3-2009 final.ppt · Due to the difficulty in its production and value...

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