Full validation and accreditation of a method to support human biomonitoring studies for trace and ultra-trace elements

This work describes the full validation of a method, in a context of quality assurance (QA), for human biomonitoring (HBM) of known and emerging trace and ultra-trace elements by high-resolution-inductively coupled plasma mass spectrometry (HR-ICP-MS) in human urine, serum and blood. The validation procedure included distinct operational steps: i) definition of the fitness-for-purpose; ii) demonstration of method performances and systematic quality control (QC) measures (including the use of control charts); iii) evidence of compliance in proficiency testing (PT) exercises and accreditation to ISO/IEC 17025. The method can be applied to monitoring single elements or mixture of elements in a broad category of human samples and in populations differently exposed, as a tool for public surveillances, hot spot programs and health risk assessments. Hopefully, the protocol can be used as a guidance towards a greater harmonization of HBM procedures and comparability of HBM results on a European-wide level.