High and low salinity seawater, estuarine water and freshwater
Proficiency tests
Participation is open to all laboratories.
| Determinand Group | Sample Type | Exercise |
| Nutrients (e.g. NO2 and PO4) | High salinity seawater | AQ1 |
| Nutrients (e.g. NO2 and PO4) | Estuarine and low salinity seawater | AQ2 |
| Metals (e.g. Cd, Cu and Zn) | High and low salinity seawater | AQ3 |
| Mercury | High and low salinity seawater | AQ4 |
| Halogenated organics (e.g. OP-DDT, CB153) | High and low salinity seawater | AQ5 |
| Volatile organics (e.g. benzene, toluene) | High salinity seawater | AQ6 |
| Pentachlorophenol | High salinity seawater | AQ7 |
| Pesticides (e.g. atrazine, chlorpyrifos) | High and low salinity seawater | AQ8 |
| Chlorophyll and Pheopigments | Estuarine and fresh water | AQ11 |
| Organotins (e.g. TBT and TPhT) | High salinity seawater | AQ12 |
| PAHs (e.g. Anthracene and Chrysene) | High and low salinity seawater | AQ13 |
| DOC | High and estuarine seawater | AQ14 |
| Ocean acidification (total alkalinity, DIC and pH) | High and low salinity seawater | AQ15 |
| Polar/nonpolar compounds | Sampler(s) | DE13 |
| PFAS | (Sea)water | DE18 |
| Pharmaceuticals | (Sea)water | DE19 |
General information
- Seawater samples are mainly prepared from seawater originating from the North Sea, Atlantic Ocean, the Baltic sea and estuarine water to cover water samples with varying salinity. For chlorophyll samples sometimes freshwater samples are used.
- Water samples are filtered using a 0.45µm / 0.2µm double membrane filter.
- The water samples are stable for the period of the test when stored properly.
- All seawater samples are prepared in bulk and tested for its homogeneity where relevant.
- Use your normal validated methods and procedures to analyse the test materials.
- Some of the PT samples (AQ5; AQ7; AQ8; AQ12 and AQ13) need to be spiked in your own laboratory because of stability issues.
- New determinands can be added to these programs on request.
- Reports contain all data reported under strict confidentiality, including Z-score plots and method information of methods used.
Webshop
Samples of previous proficiency tests are sold as reference materials. Available materials can be selected and ordered in our webshop. Participants of our proficiency tests are entitled to a discount.