The USE of GDMS in the certification procedure of reference materials

Reference materials are essential, when the accuracy and reliability of measurement results need to be guaranteed in order to generate confidence in the analysis. These materials are frequently used for determining measurement uncertainty, for validation of methods, suitability testing and quality assurance. Especially direct solid sampling methods require reference materials for calibration. They guarantee that measurement results can be compared to recognized reference values. This presentation gives an overview about the use of GDMS in various certification procedures. Because it represents a fast, sensitive, multielement analyses technique without extensive sample preparation it plays a special role for the purity determination of high purity standards. Various calibration strategies and the preparation of traceable matrix matched calibration standards will be discussed. For the certification of analyte content in matrix materials mainly techniques with solvent sample preparation are used. Here GD-MS is used to identify possible loss or contamination with analytes during the sample preparation step. Typically used acids to dissolve matrices lead to interferences in the ICP- mass spectrometric detection of various analytes and their quantification. Here GD-MS as direct method can also add an important contribution in the certification process.