Laboratory Technologies
Drinking Water Analysis
Drinking Water Analysis
A water analyzer from SEAL Analytical is ideal for automated drinking water nutrient analysis. SEAL Analytical has a range of water analyzers including, AutoAnalysers and Discrete Analysers designed specifically for environmental laboratories. The most appropriate water analyser will depend on the throughput, space needs and sample types being analysed
Drinking water analysis methods are fully compatible to USEPA, AOAC and ISO standard methods.
Specially designed for environmental analysis with features not found in competing analysers (features designed to save you money, lower your detection limits and give you constant results). Looking for an online water analyser? Click here.
Contact us on 02 4735 5054 or
USEPA, ASTM, ISO, AOAC, DIN, CORESTA and other international regulatory compliant methods.
AutoAnalyser Advantages
- SEAL (formally Technicon) has an extensive library of over 1000 drinking water analyzer methods for the AutoAnalyser 3 and QuAAtro Segmented Flow Analysers. Applications for the older AutoAnalyser II and TrAAcs systems are completely transferable to the new systems.
- Drinking water analysis and nutrient analysis methods are fully compatible to USEPA, AOAC and ISO standard methods.
- SEAL drinking water analyzers offer a wide selection of multi-test manifolds allowing a large number of different parameters to be analysed with a single channel system.
Discrete Analyser Advantages
- The SEAL Discrete Analyser is the ideal water analyzer, designed specifically for the environmental market. SEAL's library of Discrete Analyser methods includes a broad range of analytes that are important to laboratories looking to analyse water for nutrients.
- SEAL understand EPA-approved methods are critical for many laboratories and therefore they have invested significantly in this area. SEAL methods are acceptable for both wastewater (NPDES) and drinking water (NPDWR/NSDWR) nutrient analysis and compliance monitoring. Seal UKAS methods are equivalent to “UK Blue Book”
Contact us on 02 4735 5054 or
Discrete Analyser AQ400
SEAL Analytical
The AQ400 Discrete Analyser from SEAL Analytical will bring increased speed, capacity, flexibility and reproducibility to your analysis.
See also AQ300 Discrete Analyser for smaller labs, with less throughput and less space.
AQ400 Discrete Analyser
The AQ400 Discrete Analyser has been designed by SEAL Analytical chemists, manufactured in the USA and produced specifically to meet laboratory's environmental analytical chemistry needs. The AQ400 is suitable for laboratories requiring very high speed analysis and lower detection limits.
Choose the best Discrete Analyser for your laboratory.
AQ300Compact bench-top analyser for environmental laboratories |
AQ400Highest speed and capacity. Lower detection levels. |
|
| TESTS/ CHEMISTRIES | ||
| Simultaneous Chemistries | 1-14 | 1-14 |
| Tests Programmable Per Sample | YES | YES |
| Test Capacity | 180 | 216 |
| Cadmium Coil | Optional | Integrated |
| Standalone Spectrophotometer | NO | YES |
| Total Volume Per Test | 500-700 μL (sample & reagent) | 500-700 μL (sample & reagent) |
| SAMPLES | ||
| Sampling Rate | Subject to chemistry | Subject to chemistry |
| Sample Blanking | YES | YES |
| Add Samples After Run Commenced | YES | YES |
| Sample Trays (removable) | 57 & 97 positions | 80 & 120 positions |
| Sample Consumption | 2-500 μL | 2-500 μL |
| Sample Cup Sizes | 1.2 mL, 2 mL | 1.2 mL, 2 mL, 5 mL |
| Sampling Arms | 1 | 2 |
| REAGENTS | ||
| Reagent Capacity | 18 | 26 |
| Reagent Cooling | YES | YES |
| Reagent Volume | 10-500 μL | 10-500 μL |
| Reagent Wells | Disposable | Disposable |
| Reagent Monitoring | Automatic | Automatic |
| Reagent Level Sensing | Optional | YES |
| OPERATION | ||
| Auto Start Up/ Shut-down | YES | YES |
| Auto Dilution | YES | YES |
| Auto Spike Preparation | YES | YES |
| Auto Standard Preparation | YES | YES |
| Segregated Wash Waste | YES | YES |
Contact us on 02 4735 5054 or 0061 2 4735 5054 (from NZ) or
Here is why you will want to add the AQ400 discrete analyser to your laboratory:
- Working standards produced from stock solution
- Up to 10 working standards for the calibration curve
- A longer path length (optional). 1cm path length supplied standard
- Elimination of carry-over and cross contamination
- Lower detection limits
- Automatic dilution pre and post run on samples
- Programmable tests per sample
- Reduced analysis time
- An analyser that can also be used as a standalone spectrophotometer-e.g. for COD
- Completely unattended operation (ideal for overnight programmed runs)
- The ability to add samples after a run has started
- Ultra-low reagent consumption
- Cooled and non-cooled reagent positions
- Easier maintenance & easy change syringe.
Contact us on 02 4735 5054 or 0061 2 4735 5054 (from NZ) or
A Discrete Analyser With EPA Compliant Methods
- All SEAL Discrete Analysers are supported by an extensive library of methods specifically for environmental analysis .
- SEAL Analytical has individual letters of approval for SEAL Discrete Analyser environmental methods, with the letters stating the methods are acceptable for both wastewater and drinking water compliance monitoring
- Link to Discrete Analyser methods (this link takes you to SEAL Analytical's website in a new window)
Contact us on 02 4735 5054 or 0061 2 4735 5054 (from NZ) or
How Does the AQ400 Discrete Analyser Work?
- A robust sampling arm works in conjunction with a stepper motor-driven syringe that is responsible for aspirating, dispensing and mixing accurate and precise quantities of sample & reagent in miniaturised test tubes (reaction wells).
- The sample and reagent are incubated in the reaction wells for a pre-programmed time. A single aliquot is transferred into a 10mm, 100% optical glass cuvette, with the absorbance read on the stationary reactant to ensure the best possible signal to noise ratio.
- A second robotic arm moves reactant/ sample from the reaction wells to the detection area. The sample is always read in the same position in front of the detector, in the same glass cuvette, eliminating issues of scratching and reaction well variability found with direct read systems. As the liquid is moved, not the tray, fewer moving parts means higher reliability.
- Supplied standard methods have optimised reaction times ensuring the reaction is brought to completion. The complete reaction emulates the manual & segmented flow methods and ensures the lowest detection limits and good reproducibility.
- After the absorbance is read, the glass cuvetted is thoroughly cleaned and checked ensuring no carry-over or cross contamination.
- With the patented probe flusher, water from the wash bottle is pumped through the probe flusher as the probe moves up and down through it to clean the outside before dipping in the next liquid.
Contact us on 02 4735 5054 or 0061 2 4735 5054 (from NZ) or
SEAL Analytical Limited is a UK based developer of automated wet chemistry discrete analysers for use in environmental and industrial laboratories. SEAL has over 25 years experience with automated discrete analysis. Visit www.seal-analytical.com
In 2002, SEAL formed a wholly owned US subsidiary based in Milwaukee, Wisconsin to promote the sales of wet chemistry discrete analysers in the US and Canada. Subsequent to this, SEAL's international roll-out continued with distributors being approved in European and Asian Pacific countries.
In 2004, SEAL became the exclusive distributor of Bran+Luebbe Continuous Flow Analysers in the USA, UK and Ireland.
In November 2006, SEAL completed the acquisition of the Bran+Luebbe Continuous Flow Analyser (CFA) and Near InfraRed (NIR) Analyser businesses. This brings together over 50 years of CFA analysis experience of B+L , formally Technicon Industrial Systems, with SEAL's 25 year track record in discrete analysis, allowing SEAL to offer a truly complimentary solution in Automated Chemical Analysis for environmental and industrial laboratories throughout the world.
In August 2008, SEAL joined the Porvair group of companies. Porvair is a specialist filtration and environmental technology group. This will allow SEAL to continue its dynamic growth and success worldwide.
Contact us on 02 4735 5054
AA3 HR - AutoAnalyser
SEAL Analytical
Based on continuous air-segmented flow analysis principles this AutoAnalyser is specially designed for automated colorimetric determination of dissolved nutrients in environmental samples. With features not found in competing AutoAnalysers you will save money, lower your detection limits and achieve consistent results.
USEPA, ASTM, ISO, AOAC, DIN, CORESTA and other international regulatory compliant methods.
SEAL AA3 HR AutoAnalyser
The Seal AA3 HR AutoAnalyser uses continuous segmented flow analysis principles to provide significant advantages for environmental applications. With reaction times up to 20 minutes, even complex procedures like distillation can be automated. Dialysers can be built into the system for elimination of interference from dirty or colored samples. The proprietary in-line UV digestion procedure conforms to the ISO Standard Methods for automated measurement of Total Cyanide and Total Phosphorus.
The AA3 HR continuous segmented flow analysis principles utilised makes it ideal for all types of water, sea water analysis, soil, plant and fertiliser analysis when high reproducibility and low detection limits are required. It is also the world's most reliable chemistry analyser, with exceptional reproducibility, ultra-low detection limits and robust modular design.
The AA3 HR's clever design features will save you money, time and space. Features such as Multitest Manifolds, extend any single channel analyser into a multi channel analyser and allow you to rapidly change from one test to another, with only a reagent exchange.
For laboratories with smaller workloads we also have the AA1 AutoAnalyser. See the Downloads tab for more information.
Contact us on 02 4735 5054 or 0061 2 4735 5054 (from NZ) or
USEPA, ASTM, ISO, AOAC, DIN, CORESTA and other international regulatory compliant methods.
SEAL AutoAnalyser Advantages
Thanks to years of consultation with industry leaders, SEAL Analytical has continued to develop the unique features of the AA3 HR AutoAnalyser and continuous segmented flow analysis. This has helped the AA3 HR AutoAnalyser maintain its position as the first choice in fully automated systems for analysing nutrients in soil and water. When choosing an AutoAnalyser it’s worth taking a look at some of the features exclusive to the SEAL's air segmented flow injection analysis, and features designed specifically for environmental applications.
Continuous Segmented Flow Analysis to Reduce Inter-sample Dispersion
- Not all continuous flow analysers are created equal, the AA3 HR uses air segmented flow analysis principles, relying on a reaction stream segmented with bubbles of air or nitrogen to reduce inter-sample dispersion.
Same Wavelength Referencing in Real-time
- Each channel on the AA3 HR AutoAnalyser has its own high resolution digital photometer, including: its own light source (lamp or LED), wavelength filter, fibre optics, and true dual-beam technology, with same wavelength referencing in real time.
Multi-test analytical chemistry cartridges
- Allows several different tests to be performed with one manifold, and with only an exchange of reagents.
Fully Automated Modular System
- With the modular system consisting of a sampler, pump, chemistry test module, photometer and application software, the system or its components can be easily upgraded.
And More..
- Easily expanded to 8 additional channels
- Ultra-Low detection limits
- High resolution (HR) Digital Photometers standard
- Technologically advanced detection system
- No adjustment required after lamp or flowcell replacement
- Multispeed peristaltic pumps
- Reliable unattended operation
- Low reagent consumption
- Ability to add additional samples after run started; Intuitive software operating under Windows.
- Fully automatic operation- start up to shut down
- 40-100 samples per hour
- Over 1000 applications available and under continual development
- USEPA, ASTM, ISO, AOAC, DIN, CORESTA and other international regulatory compliant methods available
For laboratories with smaller workloads we also have the AA1 AutoAnalyser. See the Downloads tab for more information
Contact us on 02 4735 5054 or 0061 2 4735 5054 or
USEPA, ASTM, ISO, AOAC, DIN, CORESTA and other international regulatory compliant methods.
Continuous Segmented Flow Analysis Advantages
Wide range:
- Dilution of sample is rarely necessary
- High throughput - 3000+ results per day
- Ultra Low Detection Limits
- Less than 1ul reagent use per sample
Modular AutoAnalyser Design for high flexibility
- A One Channel AA3 HR AutoAnalyser comprises a Sampler, Pump, Chemical Manifold, Detector and Computer. This nutrient analyser can easily be extended by adding a second Chemical Manifold and a second Detector. The AA3 HR AutoAnalyser then becomes a two channel system, which measures two different analytes at the same time. Additional Detector and Manifolds can be added, as required, up to a total of 8 channels.
Dual Range Methods
- Most multitest methods are also dual-range; with separate pump tubes for high and low ranges. You can test an extremely wide range of sample concentrations. For example, the AA3 HR AutoAnalyser method for Nitrate in Seawater can measure up to 8500 ug N/L and has a detection limit of 0.14 ug/L. This same manifold can be used to measure Ammonia and Silicate.
AACE Software for Windows
- AutoAnalyser Control and Evaluation software for all Continuous Flow Analysers. For large or small systems with high or low workloads: AACE makes daily operation quicker and easier.
Digital Colorimeter
- High resolution to increase the working range
- Bubble through the flow cell to increase sampling rate
- Extended Linear Range due to advanced flowcell design
- Dual beam operation with same wavelength compensation
- Ultra low detection limits IE: 0.12 ug/L for Phosphate in Seawater
High Precision Pump
- Multi-speed motor with High Speed for fast wash out
- Optional Valves for Reagent Switching or Auto Dilution
- Software Control and at the pump
- Built in Leak Detector
Multi-test Manifold
- Multi-Test Manifolds extend any size analyser to a multiple channel analyser
- When changing from one test to another only the reagents need to be exchanged.
- Lowers purchase and maintenance costs as well as space saving
- Multi-Test Manifolds for:
- Water & Waste Water nutrient analysis
- Soil and Plant extracts
- Seawater
- Tobacco
- Feeds
- Fertilizers
- Cell Liquors
Chemistry Manifold
- Holds up to TWO chemistry method manifolds
- Glass Mixing coils - Chemically inert - clear view of the flow
- Heating bath with high-precision proportiona control and replaceable coil
XY2 / XY3, XYZ AutoSampler
- High capacity random access Sampler for large work loads.
- Up to 180 Samples in cups or tubes in two racksl
- Separate Rack for Standards
For laboratories with smaller workloads we also have the AA1 AutoAnalyser. See the Download tab for more information.
Contact us on 02 4735 5054 or 0061 2 4735 5054 (from NZ) or
SEAL Analytical Limited is a UK based developer of automated wet chemistry using air segmented flow injection analysis and discrete analysers for use in environmental and industrial laboratories. SEAL has over 25 years experience with automated discrete analysis. Visit www.seal-analytical.com
In 2002, SEAL formed a wholly owned US subsidiary based in Milwaukee, Wisconsin to promote the sales of wet chemistry discrete analysers in the US and Canada. Subsequent to this, SEAL's international roll-out continued with distributors being approved in European and Asian Pacific countries.
In 2004, SEAL became the exclusive distributor of Bran+Luebbe Continuous Flow Analysers in the USA, UK and Ireland.
In November 2006, SEAL completed the acquisition of the Bran+Luebbe Continuous Flow Analyser (CFA) and Near InfraRed (NIR) Analyser businesses. This brings together over 50 years of CFA analysis experience of B+L , formally Technicon Industrial Systems, with SEAL's 25 year track record in discrete analysis, allowing SEAL to offer a truly complimentary solution in Automated Chemical Analysis for environmental and industrial laboratories throughout the world.
In August 2008, SEAL joined the Porvair group of companies. Porvair is a specialist filtration and environmental technology group. This will allow SEAL to continue its dynamic growth and success worldwide.
Contact us on 02 4735 5054
Over 1000 Methods for AutoAnalysers
SEAL has over 1000 methods for the AutoAnalyser & Segmented Flow Analyser, giving you the best reproducibility and the lowest detection limits. SEAL also supplies a wide range of Multi-test Manifolds which allows you to analyse a large number of different parameters with a single channel system.
SEAL AutoAnalyser methods are fully compatible to USEPA, AOAC and ISO standard methods. The list below is a partial list of methods, please contact us if you don't see the application you are interested in.
Link to AutoAnalyser Multi-test methods and detection limits.
- Alkalinity
- Alkalinity (methyl orange)
- Alkaloids, total
- Ammonia (salicylate)
- Ammonia (phenate)
- Boron
- Bromide
- Calcium
- Chloride
- Chromium (6)
- Fluoride
- Hardness
- Iron
- Iron, total and free dissolved iron
- Iodide
- Magnesium
- Manganese
- Nicotine
- Nitrate
- Nitrate-Nitrite, Cadmium Column
- Nitrate-Nitrite, Cadmium Coil
- Nitrite
- Nitrogen, total (NH3 NO3 only)
- Nitrogen, total Kjeldahl
- Phenol
- Phosphate
- Phosphate (molybdovanadate)
- Phosphorous, total Kjeldahl
- Potassium
- Silicate
- Sodium
- Sulfide
- Total Volatile Bases
- Total Volatile Acidity
Contact us on 02 4735 5054 or 0061 2 4735 5054 (from NZ) or
QuAAtro - Chemistry Analyzer
SEAL Analytical
The QuAAtro is a microflow system that uses the principles of continuous segmented flow analysis: high throughput - 3000+ results per day; low reagent use; ultra low detection limits and less than 1ul reagent use per sample.
USEPA, ASTM, ISO, AOAC, DIN, CORESTA and other international regulatory compliant methods.
QuAAtro39 Continuous Segmented Flow Analyser
The QuAAtro39 is a high performance Microflow Analyser and is the latest generation of the original world-class Technicon AutoAnalyser systems. The QuAAtro AutoAnalyser uses the principles of Continuous Segmented Flow Analysis which offer: high throughput - 3000+ results per day; low reagent use; ultra low detection limits and less than 1ul reagent use per sample.
The QuAAtro39 AutoAnalyser is the world's most automated continuous segmented flow analyser with: microflow hydraulics, heated manifolds, high resolution detectors and advanced software. The QuAAtro39 also supports Multitest Manifolds to save you time, maintenance and money. Multitest Manifolds allow you to test for different nutrients with no hardware changes.
The result... Reduced operator time ... Lower Training Costs ... System Checks its own performance ... low detection limits and high reproducibility.
Contact us on 02 4735 5054 or
Advantages of the QuAAtro39 Segmented Flow Analyser
- QuAAtro39 uses micro flow hydraulics, enabling high sample rates with low sample and reagent consumption.
- QuAAtro39 is ideal for water and seawater analysis when high-throughput and ultra-low detection limits are required
- USEPA, ASTM, ISO, AOAC, DIN, CORESTA and other regulatory compliant methods are available
- One click start-up
- Reliable unattended operation
- Automatic performance checks before, during and after a run
- Can generate more than 1,000 results per day
- Multi-test manifolds for different nutrients with no hardware changes
- 5 channel seawater QuAAtro available
- Easily transportable
Contact us on 02 4735 5054 or
USEPA, ASTM, ISO, AOAC, DIN, CORESTA and other international regulatory compliant methods.
QuAAtro Segmented Flow Analyser Features
Microflow Technology - 1mm ID Glass
QuAAtro is a microflow system, the internal diameter of all glassware being 1mm. This reduces reagent consumption and increases throughput, with most methods running 100 – 120 samples hour. The optimal bubble frequency for each method is programmed by silent air valves to improve flow stability.
Manifolds and Detectors are Heated to 370 Degrees C
The integrated enclosed manifold and detector share the same temperature control system and are heated to 37º C. This reduces ownership cost and increases ease of use. It also means the system is not as susceptible to changes in environmental temperature. High temperature heating baths, distillation and dialyzers are available for methods that require them.
Automated Start-up and Shut-down
QuAAtro is designed to make life as easy as possible - with automatic start-up, automatic run-time monitoring and automatic shutdown.
High Resolution Digital Photometer
- Ultra Low Detection Limits
- UV Optimised
- 24 bit digital resolution
- optional LED Light Sources
- Bubble through the flowcell technology
Heated Chemistry Manifold
- No Need for Heating Baths
- Micro-flow Hydraulics - 1mm ID Glass
- Low waste
- Fast Chemistries
- Glass allows easy visual check
High Precision Peristaltic Pump
- 3 speed pump
- 30 pump tube positions
- Automatic shutdown
- Easily replaceable Platens
- High Precision Pump Rollers
- 4 chemistries on one console
QuAAtro Liquid Autosamplers
- Available in different sizes
- Add samples at any time
- Automatic shutdown
- Various rack sizes
- Fast and Robust
- Dedicated standards location
- 4 chemistries on one console
QuAAtro AutoAnalyser Software (AACE)
- LIMS compatible
- Intuitive - Easy to use
- Add samples at any time
- Standard and GLP versions
- Easy QuAAtro system control
- Quality Control features
Multi-test Manifolds
- Multitest Manifolds allow the testing of different nutrients without hardware exchange.
Contact us on 02 4735 5054 or
Methods For Analysing Water, Wastewater, Seawater & Low Level Water
SEAL has an extensive library of methods for analysing water, wastewater, seawater and low level water, that give you the best reproducibility and the lowest detection limits. SEAL also supplies a wide range of Multi-test Manifolds which allows you to analyse a large number of different parameters with a single channel system.
SEAL AutoAnalyser methods are fully compatible to USEPA, AOAC and ISO standard methods. The list below is a partial list of Multi-test methods, please contact us if you don't see the application you are interested in.
Link to QuAAtro Multi-test methods and detection limits.
- Alkalinity
- Ammonia
- Calcium
- Chloride
- Cyanide
- Hardness
- Nitrate/Nitrite
- Nitrite
- Nitrogen (Total Kjeldahl)
- Phenol
- Phosphate
- Phosphorus (Total Kjelhdal)
- Silicate
Contact us on 02 4735 5054 or 0061 2 4735 5054 (from NZ) or
SEAL Analytical Limited is a UK based developer of automated wet chemistry discrete analysers for use in environmental and industrial laboratories. SEAL has over 25 years experience with automated discrete analysis. Visit www.seal-analytical.com
In 2002, SEAL formed a wholly owned US subsidiary based in Milwaukee, Wisconsin to promote the sales of wet chemistry discrete analysers in the US and Canada. Subsequent to this, SEAL's international roll-out continued with distributors being approved in European and Asian Pacific countries.
In 2004, SEAL became the exclusive distributor of Bran+Luebbe Continuous Flow Analysers in the USA, UK and Ireland.
In November 2006, SEAL completed the acquisition of the Bran+Luebbe Continuous Flow Analyser (CFA) and Near InfraRed (NIR) Analyser businesses. This brings together over 50 years of CFA analysis experience of B+L , formally Technicon Industrial Systems, with SEAL's 25 year track record in discrete analysis, allowing SEAL to offer a truly complimentary solution in Automated Chemical Analysis for environmental and industrial laboratories throughout the world.
In August 2008, SEAL joined the Porvair group of companies. Porvair is a specialist filtration and environmental technology group. This will allow SEAL to continue its dynamic growth and success worldwide.
Contact us on 02 4735 5054
Advantage of Continuous Segmented Flow Analysis
In Continuous Segmented Flow Analysis , all reactions run to completion. The ratio of sample to reagents in the detector reaches a constant maximum value – the steady-state condition. This ensures maximum sensitivity resulting in lowest detection limits and exceptional reproducibility. Variations in reaction time, temperature and sample matrix do not affect the results as they do in other colorimetric techniques, such as flow injection analysis, where the reaction is not brought to completion.
Higher analysis rates and lower reagent consumption are achieved with Bubble- through-the-flowcell operation. It also makes the system easy to use. The linear range is increased for most methods by the flowcell design with planar end faces and fiber-optic coupling which ensures parallel light transmission through the flowcell.
The AA3 HR is a macroflow system, the internal diameter of all glassware being 2 mm. This enables more complex and non-homogenous sample matrices to be run without clogging. The AA3 HR allows for long reaction times as well as the automation of on-line distillation, UV digestion and other complex procedures. Most methods run at 60-70 samples hour.
Contact us on 02 4735 5054 or
How do SEAL Chemistry Analyzers Provide Advantages over Flow Injection Analysis?
There are two kinds of Continuous-Flow Analysis:
Continuous Segmented-Flow Analysis -The reaction stream is segmented with bubbles of air or nitrogen to reduce inter-sample dispersion.
Flow Injection Analysis (FIA)- There are no air bubbles in the reaction stream. The dispersion in the system is used to mix the samples and reagents.
SEAL Analytical continuous-flow analysers use Continuous Segmented Flow Analysis technology because the bubbles bring important advantages to routine analysis.
Advantage 1: Maximum sensitivity
Two factors contribute to sensitivity:
- Complete reaction between reagents and sample
- Measuring the final reaction mixture at maximum concentration
Complete reaction: If a time delay is necessary, the reaction stream can be delayed or heated. Because Continuous Segmented Flow Analysis can automate longer, hotter reactions, it allows slow reactions to proceed to completion. The advantages of complete reaction are: Sensitivity is the maximum possible and small variations in reaction conditions such as changes in flow rate or temperature do not affect method sensitivity. When the method sensitivity remains constant, results stay within specification for longer and recalibration is necessary less often.
Advantage 2: Sample concentration in the detector reaches a constant, maximum value
The output from a Continuous Segmented Flow Analysis system is a peak with a flat plateau. The plateau represents a constant "steady state" value in the flowcell at maximum concentration. The sample result is calculated from the peak height, which is averaged from readings on the plateau.
In contrast, the sample peak from a FIA system only reaches maximum concentration for an instant.
The "steady state" Continuous Segmented Flow Analysis peaks maximise sensitivity in two ways.
- The sample concentration in the flowcell reaches its maximum value, undiluted by wash or carrier solution.
- Maximum concentration is maintained for long enough to obtain an accurate reading.
Advantage 3: No interference from air bubbles
Degassing from samples or reagents can introduce unwanted air bubbles into the reaction stream. Whereas Continuous Segmented Flow Analysis systems are designed to work with bubbles in the reaction stream, air bubbles interfere with FIA in two ways.
- The pressure inside a FIA system is high, because 2-4 ml/min are pumped through tubing 0.8-1 mm internal diameter.
- Compression of the air bubble disrupts the regular flow which is necessary for reproducible results.
An air spike is easily separated from the height measurement of a Continuous Segmented Flow Analysis peak's flat plateau, but cannot be easily removed from a FIA peak, whether the area or height is measured.
Advantage 4: Low detection limit
Even at very low concentrations, maximum concentration in the flowcell is maintained for several seconds in a Continuous Segmented Flow Analysis system, so the signal can be distinguished from background noise. In contrast, the maximum concentration of a FIA peak exists for only an instant. Combined with the maximum sensitivity available from complete reaction, this results in a lower method detection limit for the Continuous Segmented Flow Analysis system.
Advantage 5: Stable, robust analysis methods
A "robust" method delivers stable, constant results over a long time and is not affected by small changes or disturbances in the analysis conditions. Several factors contribute to the stability of Continuous Segmented Flow Analysis methods.
- Even slow reactions go to completion: changes in reaction time or temperature do not affect the method sensitivity or the sample result.
- The effect on method sensitivity of a 2% increase in reaction time can easily occur as the pump warms up during the analysis and flow rates drop. The Continuous Segmented Flow Analysis method sensitivity is not affected: the FIA method sensitivity can change by 4.4%.
- Each peak reading is the average of several at maximum concentration: interferences are easy to identify and separate.
- The sample peak from an Continuous Segmented Flow analysis has a steady-state plateau at maximum concentration. This plateau consists of multiple individual data points. The final result is the average of the readings from several separate liquid segments.
- Changes in sample matrix do not affect the result.
Advantage 6: Complex procedures can be automated
Continuous Segmented Flow Analysis can automate complex and long analytical procedures such as distillation and hydrolysis. Only the SFA digestion procedure is approved in the 2004 draft of the ISO standard method for Total Phosphorus with UV digestion.
Advantage 7: Easy visual check for correct operation
The individual segments in Continuous Segmented Flow Analysis systems offer two advantages:
- The segments of liquid and air with a regular bubble pattern make it easy to see that the flow is correct and to identify the source of a problem such as a reagent which has run out or a tube which is blocked.
- The result for each segment is stored by the computer, so a complete run can be replayed for fault finding. The concentration of each segment can be displayed, to provide a validation check on the final result
Advantage 8: Interference from dirty samples is removed
Dialysers in methods for wastewater allow only small ions or molecules to pass through the membrane. Large coloured compounds, protein, fat and suspended solids are pumped to waste.
Contact us on 02 4735 5054 or
