Intercalibrative measurements of heavy metals concentration in pinewood and soil

Abstract

Each step within a composite method can be associated with a systematic error. Depending on the step, blind values, non-homogeneity of the sample, changes in the sample and errors in weighing, measuring and calibration are the most important systematic errors. Usually the concentration of the samples is measured at more than one laboratory. This is for possibility to increase precision of measurements and find out errors and their sources. Intercalibrative measurements of HM concentration in soil and pinewood were carried out in two accredited laboratories (Lithuania and Finland). During the investigation of soil samples, higher mean values of HM concentration in soil and absolute uncertainties were determined at MPI. Higher mean values of HM concentration in the pinewood and absolute uncertainties were determined in VGTU. Relative uncertainty values of the most measurements do not exceed 20 % thus regarding measurements as reliable.