Seawater
High and low salinity seawater, estuarine water and freshwater
Proficiency tests
Participation in our seawater programmes (AQ) is open to all laboratories.
| Determinand Group | Sample Type | Exercise |
| Nutrients | High salinity seawater | AQ1 |
| Nutrients | Estuarine and low salinity seawater | AQ2 |
| Metals | High and low salinity seawater | AQ3 |
| Mercury | High and low salinity seawater | AQ4 |
| Halogenated organics | High and low salinity seawater | AQ5 |
| Volatile organics | High salinity seawater | AQ6 |
| Pentachlorophenol | High salinity seawater | AQ7 |
| Pesticides | High and low salinity seawater | AQ8 |
| Chlorophyll and Pheopigments | Estuarine and fresh water | AQ11 |
| Organotins | High salinity seawater | AQ12 |
| PAHs | 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 |
| Microplastics | Diverse matrices | DE17 |
| 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 is 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.
Determinands
The list below shows the typical determinands for the seawater, estuarine water and freshwater Programme. For a list of determinands which are under the scope of accreditation please check here.
| Analyte group | Typical analytes | Exercise |
| Brominated flame retardants | BDE28, BDE47, BDE49, BDE66, BDE85, BDE99, BDE100, BDE126, BDE153, BDE154, BDE183, BDE209, TBBP-A, Dimethyl-TBBP-A, a-HBCD, b-HBCD, g-HBCD, Total HBCD, BTBPE, DBDPE, HBBz, EHTBB, EHTEBP | DE13 |
| Dissolved Organic Carbon | DOC | AQ14 |
| Metals | Arsenic, Boron, Cadmium, Chromium, Cobalt, Copper, Iron, Lead, Magnesium, Manganese, Mercury, Nickel, Silver, Strontium, Thallium, Tin, Vanadium, Uranium, Zinc | AQ3, AQ4 |
| Microplastics | Total number of particles, Total mass of particles | DE17 |
| Nutrients | Ammonia, Nitrate, Nitrite, Phosphate, Silicate, TOTAL-N, TOTAL-P, TOxN | AQ1, AQ2 |
| Ocean acidification | Dissolved Inorganic Carbon, Total Alkalinity, pH | AQ15 |
| OPs&Herb | Aclonifen, Alachlor, Atrazine, Atrazine-desethyl, Azinphos-ethyl, Azinphos-methyl, Bifenox, Bifenthrin, Chlorfenvinphos, Chlorpyrifos, Chlotianidin, Coumaphos, Cypermethrin, Deltamethrin, Demeton, Diazinon, Dichlorvos, Dicofol, Dimethoate, Diuron, Esfenvalerate, Fenchlorophos, Fenitrothion, Fenthion, Glyphosate, Imidacloprid, Irgarol-1051, Isoproturon, Malathion, Nicosulfuron, Omethoate, Parathion-ethyl, Parathion-methyl, Permethrin, Quinoxyfen, Simazine, Terbutryn, Terbuthylazine, Thiacloprid, Thiamethoxam, Triazophos, Triclosan | AQ7 |
| Organometals | Dibutyltin(DBT), Diphenyltin(DPhT), Monobutyltin(MBT), Monophenyltin(MPhT), Tributyltin(TBT), Triphenyltin(TPhT) | AQ12 |
| PCBs&OCP | a-HCH, b-HCH, g-HCH, d-HCH, HCB, HCBD, Aldrin, Dieldrin, Endrin, Isodrin, pp'-DDD, pp'-DDE, op'-DDT, pp'-DDT, Endosulphan-I, Endosulphan-II, Pentachlorobenzene, 1-2-3-TCB, 1-2-4-TCB, 1-3-5-TCB, Trifluralin, PCB28, PCB31, PCB52, PCB101, PCB105, PCB118, PCB138, PCB138+PCB163, PCB153, PCB156, PCB180, Heptachlor, Heptachlorepoxide, Pentachlorophenol | AQ7, DE13 |
| Perfluorinated alkyl substances | PFOS, PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoA, PFTrDA, PFTeDA, L-PFBS, L-PFHxS, L-PFHpS, PFOSA, PFDS, PFODA, GenX, F-53B, PFBSA, PFHxSA, NMeFOSAA and NEtFOSAA | DE18 |
| Pigments | Chlorophyll-a, Chlorophyll-b, Chlorophyll-c, Pheopigments, Chlorophyll-a (Corr), Chlorophyll-a (HPLC), Chlorophyll-b (HPLC), Chlorophyll-c (HPLC) | AQ11 |
| Polycyclic aromatic hydrocarbons | Acenaphthene, Acenaphthylene, Anthracene, Benzo[a]anthracene, Benzo[a]pyrene, Benzo[b]fluoranthene, Benzo[e]pyrene, Benzo[k]fluoranthene, Benzo[g,h,i]perylene, Chrysene, Dibenzo[ah]anthracene, Fluorene, Fluoranthene, Indeno[1,2,3-cd]pyrene, Naphthalene, Phenanthrene, Pyrene, Total petroleum hydrocarbons | AQ13, DE13 |
| Salinity | Salinity, Salinity indicative | AQ1, AQ2 |
| VOCs | Benzene, Carbon-tetrachloride, Chlorobenzene, Chloroform, 2-chlorotoluene, 4-chlorotoluene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,1-dichloroethane, 1-2-dichloroethane, 1,1-dichloroethene, cis-1,2-dichloroethene, trans-1,2-dichloroethene, Dichloromethane, 1,2-dichloropropane, Ethylbenzene, Isopropylbenzene, n-Propylbenzene, Styrene, tert-bytylbenzene, 1,1,1,2-tetrachlorethane, Tetrachloroethene, Trichlorethene, 1-1-1-trichloroethane, 1-1-2-trichloroethane, 1,3,5-trimethylbenzene, Toluene, m+p-Xylene, o-Xylene | AQ6 |
Reference materials
Samples of previous proficiency tests are sold as reference materials. Available materials can be selected and ordered in our webshop. In our webshop it is also possible to request a quotation. Participants of our proficiency tests are entitled to a discount.