The EQAT scheme has its origin in the quality management activities of the biology workgroup of the Arbeitsgemeinschaft Trinkwassertalsperren (ATT e.V.) in the 1990s. Since 2002, the proficiency test phytoplankton has been carried out on an international level by the LTV.
We are happy to have 68 participants from 12 different countries for the EQAT proficiency test phytoplankton 2025/ 2026.
On Monday 10.11.2025 the reference counting chambers and natural samples have been sent in the post. Please contact us if it has not arrived on 24.11.2025.
The analysis period runs from 15.11.2025 - 15.02.2026.
The submission of results is only possible via the web portal. Please contact us immediately if any problems arise in the process.
After completion of this phase, results can no longer be submitted.
Inter-laboratory comparisons are an essential part of external quality assurance. Laboratories can test and improve their analytical performance. The EU Water Framework Directive sets high standards for the quality of phytoplankton analysis and requires regular participation in proficiency testing. EQAT Phytoplankton organises such ring trials every 2 years, with typically between 60 and 70 participants. The German Accreditation Body, DAkkS (www.dakks.de), accredits EQAT Phytoplankton for phytoplankton analysis according to DIN EN ISO 17025:2018 and as a provider of interlaboratory comparisons according to DIN EN ISO/IEC 17043:2010. With the help of the innovative reference counting chamber developed by EQAT Phytoplankton, systematic errors can be clearly distinguished from errors related to the detection of algae. This is done within the established work processes at the inverted microscope (Utermöhl technique).
The proficiency tests are based on the procedures described in the DIN EN 15204:2006 Guidance standard on the enumeration of phytoplankton using inverted microscopy (Utermöhl technique) and in DIN EN 16695:2015 Water quality - Guidance on the estimation of phytoplankton biovolume.
