Certified reference materials for analytical mercury speciation in biological and environmental matrices: do they...

The usefulness of a certified reference material (CRM) for analytical method validation and quality control purposes is attributed mainly to its key properties, namely homogeneity and stability. However, it is also advisable to select suitable CRMs in terms of representativeness. To assess the representativeness of a CRM for analytical mercury speciation, a number of aspects must be considered in regard to the routine samples analyzed: the origin of the matrix, the type of mercury species and the level of concentration. This review critically analyzes the availability of current CRMs for mercury speciation analysis in environmental and biological fields. The characteristics of the CRMs are compared with the matrices and samples covered in papers published in the last five years on mercury speciation, mainly in water, soils, sediments, sewage sludge, seafood, blood, urine and hair.