Honey as a candidate reference material for trace elements

The feasibility of producing and certifying new certified reference materials (CRMs) for trace elements in honey was investigated. Preliminary steps for preparation of candidate materials are performed at the Institute for Reference Materials and Measurements, Joint Research Centre of the European Commission (EC-JRC-IRMM). Two different types of honey, Acacia and Eucalyptus, were tested for determination of 10 trace elements. To each type of honey was added a given amount of high purity deionized water to obtain aqueous solutions with an acceptable degree of homogeneity which would require only minimal manipulation before analysis. Average values obtained for the trace elements by means of inductively coupled plasma-based techniques were as follows (in mug/kg SD): Acacia honey, As, 1.10 +/- 0.20; Cd, 0.328 +/- 0.035; Cr, 1.90 +/- 0.22; Cu, 67.0 +/- 5; Fe, 215 +/- 30; Hg, < 0.75; Mn, 82.1 +/- 6.2; Ni, 21.0 +/- 3.0; Pb, 2.30 +/- 0.25; Se, 9.10 +/- 1.2; Zn, 167 +/- 22; Eucalyptus honey, As, 5.99 +/- 0.10; Cd, 0.592 +/- 0.074; Cr, 1.50 +/- 0.07; Cu, 219 +/- 24; Fe, 1008 +/- 114; Hg, <0.75; Mn, 1009 +/- 51; Ni, 11.3 +/- 1.5; Pb, 5.00 +/- 0.40; Se, 5.60 +/- 0.91; Zn, 791 +/- 91. When these 2 pilot materials are ready, the certification project will be launched in full compliance with current rules set by EC-JRC-IRMM. If the project is successful, the new CRMs will be put primarily at the disposal of the National Reference Laboratories for trace elements.