Samples
Interlaboratory comparison samples prepared at the IFA-Tulln usually consist of synthetic ground or surface water, which is made from pure water, salts and pure standard chemicals. Reference concentrations are calculated from the gravimetric data of sample preparation. The estimation of the laboratories' performance is based on the recoveries of these reference concentrations. Therefore, it is independent of the number of participants per round.
The reference concentrations of the parameters are chosen with respect to the concentrations observed in natural ground and surface waters. It is always aimed to represent the relevant inorganic matrix as close to natural water samples as possible. Thus, our PT samples are not simple standard solutions, but prepared in such way that they practically do not differ from real water samples. They can be analysed exactly like real samples in routine analysis. No additional preparation steps are necessary.
Two samples at different concentration levels are distributed to the laboratories in each laboratory comparison round.
Based on extensive quality assurance measures during the sample production, we can ensure high accuracy of the target concentrations. The correctness of the reference values, homogeneity and stability of the PT samples are carefully checked at the IFA-Tulln. For this purpose, samples are randomly selected and analysed for the target compounds before sample dispatch and after the closing date. The results of these measurements are presented in the reports.
General
In Austria, the quality of ground- and surface-water is monitored since the early 90´s of the last century. About 2000 groundwater and 200 river water sites are sampled regularly and analysed for numerous inorganic and organic parameters in a nationwide measurement network. The exact range and frequency of the water analyses are legally regulated. This permanent and comprehensive measurement programme requires reliable and accurate results of analysis.
In 1995, the Institute of Bioanalytics and Agro-Metabolomics at the IFA-Tulln started to build up a PT scheme for external quality assurance in water analysis on behalf of the Austrian Federal Ministry of Agriculture, Forestry, Environment and Water Management (BMLFUW). Since then, this scheme has been extended to a multiplicity of inorganic and organic parameters. It has become an important part of the nationwide measurement programme.
The PT scheme is open to all laboratories that are interested in testing their analytical performance. In 2010, more than 200 laboratories from different countries participated in our PT scheme.
Successful participation in the scheme is recognised by the national accreditation body in the Federal Ministry of Economy, Family and Youth of the Republic of Austria.
The IFA-Tulln is located close to the Danube approximately 40 kilometres northwest of Vienna and was opened in 1994. It is a department of the University of Natural Resources and Life Sciences, Vienna and is now called "Department for Agrobiotechnology, IFA-Tulln".
Our institute, the Institute of Bioanalytics and Agro-Metabolomics, has 800 m2 laboratory space and modern instrumentation for environmental trace analysis.