Sea Water Analysis with Segmented Flow

SEAL Analytical Segmented Flow Analysis Methods for Nutrient Analysis in Sea Water

The high precision, robust design and low detection limit of SEAL Analysers make them the first choice for seawater analysis.  Leading seawater laboratory and research institutes world wide use the AA3 AutoAnalyser and QuAAtro for onboard nutrient analysis.


SEAL Analysers are designed to stand up to tough conditions on board an ocean-going research vessel, and are in routine ship-board use from the Arctic Ocean to the Weddell Sea.  The latest instruments use LED light sources as they are unaffected by vibration and are extremely stable.  A special bench fixing kit is available for the SEAL Analytical QuAAtro to quickly and securely mount it into a floating laboratory.

SEAL analysers are the only SFA instruments which measure the precision of the bubble pattern, flowcell cleanliness, chemistry drift and other performance-critical parameters before and during a run. More than 30 hydraulic, optical, electrical and chemical parameters are quantified and written into a performance log which gives a long-term record of instrument and method performance.



Pre-run Check Quantifies System


A simple pre-run check quantifies the bubble pattern, baseline, detector, flowcell and light source in a few minutes and creates a printed record of the results. This is ideal for labs which need auditable proof that the analyser is working correctly, and as a valuable aid to troubleshooting.



High Precision Segmentation 


On a SFA system the key factor in reproducibility, which is also critical for detection limit, is  the composition of the liquid segments passing through the analyser. Each segment must contain the same proportion of reagent and sample, and the arrival time of each segment at the reagent injection points must be very precise. 



Seal Electronic Air Injection vs. Mechnical Air Injection


SEAL analysers achieve this high precision with electronic air injection.  The timing of the air injection is determined by a chopper wheel which intercepts a light beam, this triggers a solenoid valve to inject the air. In contrast, mechanical systems which use a cam and lever device are less accurate even when new, and the air timing becomes progressively less precise as the pump ages. With mechanical air injection the bubble precision on a typical nutrient manifold is around 2%. With electronic injection it is improved to less than 1%. On the QuAAtro it is 0.2%.     

Link to SEAL Analytical website for detailed AA3 Sea Water methods

Link to SEAL Analytical website for detailed QuAAtro Sea Water methods.

Call 02 4735 5054 to discuss your sea water analysis requirements.