Determination of Mercury in One Hundred and Sixteen Geological and Environmental Reference Materials Using a Direct Mercury Analyser

The mercury content of 116 reference materials (RMs) from ten international organisations was determined in this study, which focused on variability within and between batches of RMs. Direct mercury analysis (DMA) was applied to RMs having Hg contents between 1 and 6300 ng g−1 and provided good precision and accuracy. Accuracy was demonstrated by the agreement of our results with certified values, while replicates were made to establish the precision. Low within-batch variability was noted, with precision from 0.1 to 23% (n = 3–5) apparently depending on Hg content and homogeneity, whereas systematic offsets were detected among several batches. Thanks to the analysis of different batches; the homogeneity or heterogeneity of several RMs was shown, and thus, suitable RMs for quality control for Hg determinations could be recommended. La concentration en mercure a ete determinee dans 116 materiaux de reference (RMs) geologiques et environnementaux issus de 10 organisations internationales. Notre etude porte sur la variabilite intra et inter lots de materiaux de reference dont les concentrations en mercure varient de 1 a 6300 ng g−1. Les mesures ont ete effectuees avec un analyseur direct de mercure. La justesse des resultats a ete demontree par comparaison aux valeurs certifiees et la fidelite par la realisation de replicats d'analyse. Une faible variabilite au sein d'un meme lot a ete etablie pour l'ensemble des RMs, apparemment dependante de la concentration en Hg et de l'homogeneite des echantillons, l'ecart-type relatif varie de 0.1 a 23% (n = 3 a 5), alors qu'une dispersion importante a ete constatee pour nombreux d'entre eux entre les bouteilles. L'analyse de lots distincts a permis la mise en evidence de l'homogeneite ou de l'heterogeneite de plusieurs RMs et nous recommandons donc l'utilisation des materiaux de reference adequates pour les controle qualite lors de l'analyse du Hg.