A pilot study for the production of a certified reference material for trace elements in honey

In the context of the general mandate of the European Union Community Reference Laboratory (CRL) for residues in living animals and their products established at the Istituto Superiore di Sanita, a pilot study was undertaken to assess the possibility of producing a new certified reference material (CRM) for trace elements in a matrix of honey. The elements considered were As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sn, V and Zn. Their determination was performed by inductively coupled plasma (ICP)-based techniques. Data obtained with different ICP techniques were generally in good agreement. In light of these results, the next step was the effective production of a candidate CRM in a honey matrix. In the preliminary phase, two different types of honey, i.e., Eucalyptus (solid and sticky) and Robinia (viscous and sticky), were pretreated at the Institute for Reference Materials and Measurements, Joint Research Centre, European Commission (EC-JRC-IRMM) in order to produce the materials candidate for the certification process. Approximately 600 ampoules were thus produced for the Robinia honey and 450 ampoules for the Eucalyptus honey, each ampoule containing 5 g of an aqueous solution of honey (with 20% and 30% high purity water, respectively) and sealed under inert gas (Ar). A ring test to determine the levels of the chemical elements and a long-term study to evaluate the stability of the samples is in progress. Tentative figures for the analytes of interest are (in ng g(-1)): Robinia, As, 1.28 +/- 0.09; Cd, 0.59 +/- 0.08; Cr, 2.36 +/- 0.21; Cu, 57.6 +/- 3.2; Fe, 209 +/- 9; Mn, 90.8 +/- 3; Ni, 18.1 +/- 0.6; Ph, 23 +/- 1.5; Sn, 8.10 +/- 0.35; V, 1.19 +/- 0.37; and Zn, 178 +/- 4; Eucalyptus, As, 3.18 +/- 0.21; Cd, 0.70 +/- 0.08; Cr, 2.73 +/- 0.22; Cu, 141 +/- 6; Fe, 926 +/- 16; Mn, 1905 +/- 81; Ni, 7.77 +/- 0.4; Pb, 138 +/- 4; Sn, 7.97 +/- 0.16; V, 3.47 +/- 0.15; and Zn, 405 +/- 9. (C) 2000 Elsevier Science B.V. All rights reserved.