QuAAtro39 Nutrient analyser | Flanders Marine Institute

Flanders Marine Institute

Platform for marine research

QuAAtro39 Nutrient analyser

The QuAAtro39 is a segmented flow analyzer (SFA) which can be used for the determination of the concentration of various nutrients in water. Knowledge of nutrient concentration is essential in order to assess the quality of the aquatic environment (which is under pressure due to marine pollution and eutrophication) and its biogeochemical status.

How does the QuAAtro39 work?

Seawater samples and reagents are continuously pumped through a manifold, while air bubbles are introduced to initiate chemical reactions. These reactions result into the development of a specific color and its intensity is proportional to the concentration of the specific nutrient. The instrument is equipped with high-precision spectrophotometers (used to measure the intensity of the color) resulting in the analysis of each nutrient. An auto-analyzer allows the analysis of about 60 samples each hour.

Use of the QuAAtro39?

The QuAAtro39 allows determining the concentration of various nutrients in (sea) water. The VLIZ-device measures the amount of total oxidizable nitrogen (TON), nitrite (NO2-), phosphate (PO43-), silica (Si) and ammonium (NH4+). These nutrients provide us information about the origin of the water or its degree of pollution.

Some studies:

VLIZ is used for the analysis of ICOS and Lifewatch samples from the Belgian part of the North Sea. These are gathered at fixed station during monthly recurring campaigns. Also the determination of water masses in the Atlantic Ocean by Ghent University was done using the QuAAtro 39.

Technical details

High resolution digital spectrophotometer with ultra-low detection limits

Heated chemistry manifolds (37 °c)

High precision peristaltic pump (3 speed options)


 Accuracy: ± 0.5 umol/l for all nutrients

Want to use the QuAAtro39?

The QuAAtro39 is a complex device that can only be operated by trained personnel. For more information on determination of nutrients in seawater samples, please contact VLIZ (infrastructure@vliz.be).

Use and conditions

Note: if you use the QuAAtro39 of VLIZ as a scientist, please refer to it in your publications as follow: "This work was supported by data & infrastructure provided by VLIZ as part of the Flemish contribution to ICOS."


The QuAAtro 39 was funded by ICOS and VLIZ