Abstract. The CCQM-P29 was performed in parallel to the CCQM-K24 key comparison in order to demonstrate and document the capability of interested national metrology institutes to measure the Cd and Zn amount content in a rice sample. The comparison was an activity of the Inorganic Analysis Working Group of CCQM and was piloted by the Institute for Reference Materials and Measurements (IRMM, Geel, Belgium) of the European Commission. It was decided during the IAWG meeting, April 2002, BIPM, Paris not to include the Cd measurements results from participants in CCQM-K24 in this CCQM-P29 pilot study.

The methods applied were isotope dilution mass spectrometry (IDMS) using thermal ionisation MS (TIMS), sector field or quadrupole inductively coupled plasma MS (ICP-MS), inductively coupled plasma emission spectrometry (ICP-AES) and neutron activation analysis (NAA) using instrumental neutron activation analysis (INAA) and k₀-NAA as analytical technique.

NIST reported two results for Cd and Zn measurements (IDMS and INAA). VNIIM reported two results for Zn (ICP-MS and ICP-AES). The following laboratories participated in this pilot study (in alphabetical order).

BAM, Germany
CENA, Brazil
CENAM, Mexico
IRMM, European Union
KRISS, South Korea
LGC, United Kingdom
LNE, France
NARL, Australia
NIST, United States of America
NMi, The Netherlands
NMIJ, Japan
NRC Canada
NRCCRM, China
PTB, Germany
VNIIM, Russian Federation

The reported results of all participants are displayed in this report. Good agreement of reported results was observed. To be complete the results for Cd measurements of all participants in CCQM-P29 and CCQM-K24 are also graphically displayed in this report.

Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database www.bipm.org/kcdb.

The final report has been peer-reviewed and approved for publication by the CCQM Working Group on Inorganic Analysis according to the provisions of the Mutual Recognition Arrangement (MRA).