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Sea Water Analysis- Recommended Instruments

Leading laboratories and marine research institutes worldwide trust their sea water analysis to SEAL AutoAnalyzers. The AA500 is the latest AutoAnalyzer from SEAL and is ideal when a modular or larger ID system is preferred or when upgrading from an older AAII AutoAnalyzer. Choose the QuAAtro when space is at a premium or for higher throughput requirements. Both instrument's high precision, robust design & ultra-low detection make them the first choice for sea water analysis. Either analyzer is equally at home on-board ocean going research vessels or in land-based laboratories. Special design features like LED light sources ensure these analyzers are extremely stable and unaffected by vibration.

Continuous Segmented Flow Analyzer

SEAL has the technology advantage in sea water analysis.

SEAL AutoAnalyzers are ideal for sea water analysis, boasting some of the most significant technology advantages available in AutoAnalyzers, ensuring the detection of extremely low nutrient concentrations and highly accurate, repeatable results.

Seawater analysis

The Technology Advantages

  • Developed for trace-level onboard sea water analysis
  • LED light source- very stable, long life and no filament so completely immune to vibration.
  • Available for all nutrient parameters.
  • Tested in a Force 10 gale and subsequently proven in many ship laboratories around the world.
  • Due to the detectors extremely low noise and high digital resolution a 10mm path-length cell can be used in place of the 50mm required on older analogue systems. This maximizes light transmission and minimizes the refractive index blank RIB.
  • Longer path-length flowcells, including LWCC 500mm and 1000mm are available for even lower detection.
  • Bubble-through-the-flowcell operation maintains separation between the sample and wash preventing "horns" at the start and finish of sample peaks whose salinity varies from the wash.
  • Concentric sapphire light pipes and the narrow angle light source from an LED provides a near-parallel light beam which further reduces the refractive index blank compared to conventional cells.

Measuring and recording instrument performance 

SEAL analyzers are the only segmented flow analyzers (SFA) instruments to 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 analyzer is working correctly, and as a valuable aid to troubleshooting.

High Precision Segmentation
On a segmented flow analyzer (SFA) one key factor in reproducibility, which is also critical for detection limit, is the composition of the liquid segments. 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 analyzers 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 less than 0.5%.

Colorimeter Design- Low noise and drift

  • Sample and reference detectors are installed close together in a massive aluminum housing to ensure temperature equilibrium.
  • The signal is immediately digitized to prevent inductive interference.
  • Same-wavelength blank correction for ultra stable real time readings. 
  • Ultra low noise electronics contribute.



JAMSTEC Seawater replicate peaks at 60 samples per hour: Seal Analytical QuAAtro