Comparison on determination of gold content in white alloy

Project Description

Proposers of the comparison are NMIs acting as reference laboratories for determination of precious metals in jewellery alloys with registered CMCs in BIPM database for the reference measurement of mass fraction of gold in yellow gold alloys (QM SI_8: SKM 1, December 2011 and QM BA_8: LH1, July 2015, respectively).
The aim of this study is to demonstrate technical competences of NMIs/DIs with specific purpose of comparing different analytical methods with different traceability demonstration.
The coordinator of the comparison is IMBiH (Pilot Laboratory) providing matrix reference material - a white gold alloy with the nominal value for the mass fraction of gold of 585 mg/g. Participants can conduct measurements of the mass fractions of gold by gravimetric method or other quantitative methods for the analysis of gold content in white gold alloys included, but are not limited to optical and mass spectrometry of dissolved sample. Participation in this comparison as a EURAMET TC-MC pilot study is open to all interested EURAMET NMIs/DIs.

Progress Report 2022-03-17

IMBIH purchased five units of the same lot of high purity gold and started contracting GDMS Au content analysis from NRC, originally planned for July 2021. Due to administrative difficulties in contracting the certification service, no progress was made in 2021. Meanwhile, an alternative route  for contracting the service has been identified. Samples will be shipped to the participants by the end of 2022.

Progress Report 2021-04-16

IMBIH purchased five pieces of the same lot of high purity gold and started contracting GDMS Au content analysis from NRC. Analysis was planned for July 2020 but has been postponed due to COVID-19 pandemic restrictions. The shipment of samples and reference material to participants (PTB, UME, MIRS) is postponed to September 2021. PTB and UME made progress in developing the ICP-OES procedure for Au analysis.

Progress Report 2020-03-10

IMBIH purchased different lots of high purity gold to be analysed with the help of the NRC GDMS service for analysing Au material (June/July 2020).
Shipment of samples together with reference material to participans (PTB, UME, MIRS) in October/November 2020. PTB has made progress in developing ICP-OES procedure.

Progress Report 2019-01-29

The draft protocol of comparison was prepared and sent to the other participants for comment. The samples are ready for distribution to all participants. 

Metrology in Chemistry (MC)
Coordinating Institute
IMBiH (Bosnia and Herzegovina)