Course of a Proficiency Testing Series

For a better understanding of the organizational process of the synthetic proficiency tests of the IFA-Tulln, the essential steps from the registration to the final report are explained in the following section.


Participation in the PT scheme is treated anonymously and confidentially. The names of the participants will not be listed in the reports. Moreover, names and mailing addresses will not be passed on unless the participants explicitly agree to do so. All results are treated strictly confidential. A letter code is randomly assigned to each participant in the final report. Each laboratory receives only its own letter code.

Ordering of samples

For registration the fully completed registration form will be sent to the IFA-Tulln no later than two weeks before the shipping date. Within a few days you will receive an order confirmation stating the shipping dates and the expected delivery time as well as the costs.

Sample dispatch

The samples are mailed to the participants with the parcel services DPD or EMS. A delivery time of two to five working days must be expected for shipping within Europe.
Deliveries to non-EU countries may be delayed due to customs clearance.
Any delivery delays that may occur cannot be ruled out.

The shipping dates can be found in the programme overview or the registration form.

For stabilization, the samples are sent cooled. Transport is carried out in disposable cooling boxes made of styrofoam. Depending on the parameter group, we ship bottles made of plastic or aluminium. The samples of the parametergroup "metals" are stabilised with 0.5 % HNO3 (v/v).

Analysis of samples

The selection of the analytical method and the number of replicate measurements are completely up to the participants. If analytical standard methods are suggested in the announcement, it is possible to replace them by equal or better methods. For all other parameters, use the methods applied in routine analysis. There are no limitations regarding the number of analyzed parameters. The decision, how many parameters will be analyzed, is made by the participants.

Although we check the stability of the samples by measurements within each round, we recommend analyzing the samples as soon as possible upon receipt. This recommendation particularly applies to less stable parameters like e.g. ammonium, phosphate, nitrite, DOC, mercury and silver. In any case the samples are to be kept unopened, cooled and stored in the dark until analysis.

Reporting results to the IFA-Tulln

The results must be transmitted to the IFA-Tulln within four to five weeks after sample dispatch. The closing date of each round is mentioned in the schedule and in the instructional letter attached to the samples. On the respective websites you can also find the detailed description of the rounds in question. In the period from the sample dispatch to the deadline for transmitting results, you can find a results form online. You can fill out this form, print it out, sign it and send it to us by e-mail (fax). For each parameter and sample we require and evaluate only one result together with its uncertainty.

The target values and reports will be published here shortly after the submission deadline for the results. For this reason, we can no longer accept results that arrive late. Each participant receives a confirmation of participation for each sample, in which the z-scores are shown in tabular and graphic form, as well as the recoveries.