Determination of Cd and Pb in honey by SF-ICP-MS: Validation figures and uncertainty of results

A method based on microwave-assisted acid digestion of honey and quantification of Cd and Pb by Sector Field Inductively Coupled Plasma Mass Spectrometry was in-house validated and the combined uncertainty was estimated according to the Eurachem/Citac Guide. Limits of detection and quantification were 0.07 and 0.20 ng g(-1) for Cd, and 0.70 and 2.10 ng g(-1) for Pb; recovery was 103.9% for Cd and 98.5% for Pb; repeatability was 10.7% for Cd and 18.5% for Pb; within-laboratory reproducibility was 15.2% for Cd and 21.4% for Pb. Relative combined uncertainty in honey was 15% for Cd and 22% for Pb, with the main contribution coming from the within-laboratory reproducibility. The method showed robustness when subjected to different working conditions and when applied to various Italian honeys. Cadmium content ranged 0.2-1.37 ng g(-1) and Pb 4.6-30.5 ng g(-1) in flower honeys, while the highest concentrations were presented by honeydew honeys.