The so-called German Medical Devices Act as well as important guidelines like RiLiBÄK render the SI traceability of (among others) the concentration of the electrolytes in human serum a requirement. This was the reason for us to develop suitable primary measurement methods for the determination of the mass fractions of lithium, potassium, sodium, magnesium, calcium, chloride, and iron. In the framework of international comparisons (CCQM), we regularly demonstrate the validity and comparability of these measurement methods. The line-up of the elements, we provide high-level methods for, is growing still. Additionally, methods with a higher efficiency and only slightly increased uncertainties compared to the primary methods are developed in order to provide proper dissemination methods for clinical results. Both categories of methods are permanently improved with regard to the measurement uncertainty and updated to come close to or define the state-of-the-art.
PTB-ThEx-19, 2001, ISBN 3-89701-739-3
Accred Qual Assur (2004) 9:671-677
Microchim Acta (2006) 154, 21-25
Scand J Clin Lab Invest (2012) 72(3):212-220
Metallomics (2012) 4, 1239-1244
Anal Bioanal Chem (2013) 405:1913–1919