title: Development and validation of a method for mercury determination in seawater for the process control of a candidate certified reference material.
abstract: A simple, robust and reliable method for mercury determination in seawater matrices based on the combination of cold vapour generation and inductively coupled plasma mass spectrometry (CV-ICP-MS) and its complete in-house validation are described. The method validation covers parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), trueness, repeatability, intermediate precision and robustness. A calibration curve covering the whole working range was achieved with coefficients of determination typically higher than 0.9992. The repeatability of the method (RSDrep) was 0.5 %, and the intermediate precision was 2.3 % at the target mass fraction of 20 ng/kg. Moreover, the method was robust with respect to the salinity of the seawater. The limit of quantification was 2.7 ng/kg, which corresponds to 13.5 % of the target mass fraction in the future certified reference material (20 ng/kg). An uncertainty budget for the measurement of mercury in seawater has been established. The relative expanded (k = 2) combined uncertainty is 6 %. The performance of the validated method was demonstrated by generating results for process control and a homogeneity study for the production of a candidate certified reference material.
authors.affiliation: European Commission, Joint Research Centre (JRC), Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, 2440, Geel, Belgium.
authors.forename: Raquel
authors.initials: R
authors.lastname: Sánchez
authors.forename: James
authors.initials: J
authors.lastname: Snell
authors.forename: Andrea
authors.initials: A
authors.lastname: Held
authors.forename: Hendrik
authors.initials: H
authors.lastname: Emons
mesh_terms: D002138:Calibration; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D012015:Reference Standards; D012623:Seawater / Q000737:chemistry*
chemical_list: D008628:Mercury