Robotic analyzers

Overview

Skalar’s sophisticated SP2000 robotic platform offers dedicated and flexible automation solutions for routine analytical testing. Automation is available for a variety of applications including: BOD, COD, Test kit applications (ST-COD, TP, TN etc.), pH, Conductivity (EC), Alkalinity, Carbonate/Bicarbonate, Turbidity, Color, Ion Selective Electrodes (ISE) applications and Particle size distribution analysis in soil, Automatic weighing and filtration of the sample, Automatic sample pipetting etc.. Combinations of analyses or custom-made applications are also possible. All applied methods are in compliance with international regulations ISO, EPA, Standard Methods, DIN etc.

The modular design and flexible user-defined automation allows the instruments to meet your exact requirements resulting in increased productivity and accuracy of results, while reducing the sample turn-around time, costs per sample and eliminating errors and operator/sample interaction.

The instruments can be built with one or two robotic arms giving a total of 8 independent movable manipulators. With this second arm it is for instance possible to increase the sample throughput by using multiple probes or to perform two applications at the same time such as BOD and COD or other combinations.

The complete platform is enclosed with a protective front and side covers to comply with applicable CE regulations. The analyzers are controlled by RoboticAccess^TM, a very practical software package, including pre-set application files, analyses scheduler, user definable sample table set up, user definable print & export options to LIMS/Excel  and extensive QC features.

The SP2000 platforms are upgradeable and can be modified according your changing needs, making your initial investment even more valuable.

BOD

Biochemical Oxygen Demand (BOD) analysis is one of the most common applications for water laboratories. The test is used as an indication of the organic quality of water. With the SP2000^series Skalar introduces the most flexible Robotic BOD platform available today. Besides the modern design and latest technology innovations, it has a flexible set up from 18 up to 198 BOD bottles. The analyzer is developed to fit your exact laboratory requirements with respect to sample throughput, level of automation, sample capacity etc. Analysis are carried out in accordance with all (inter) national regulations such as EPA 405.1/ISO 5815-1/ EN-1899-1/2, Standard Methods 5210 B, DIN 38409 etc. as well as customer specific methods.

The basic system:

The smallest and most basic Skalar Robotic BOD analyzer consists of a XYZ sample handling platform, a bottle tray with 18 BOD bottle positions, an oxygen probe and meter (accommodates optical or membrane style electrodes,) a manipulator, a stirrer, rinsing station and protective front and side covers.

In addition to this basic configuration the following automatic steps are available for complete BOD automation:

1. Automatic addition of dilution water
2. Automatic ATU dispensing
3. Automatic Seed dispensing
4. Automatic capping/ de-capping
5. Automatic sample pipetting
6. Automatic incubation

The systems can be extended to hold up to a maximum of 11 BOD racks and the use of multiple oxygen probes allow a higher sample throughput. A second arm can also be implemented to increase sample throughput or to perform additional tasks such as automatic sample pipetting into the BOD bottles or pH setting of the sample. The analyzer can be used with all available standard BOD bottles, and a wide range of sample trays can be provided for various incubators.  A completely closed cover is also possible for incubation purposes.

A typical BOD analysis sequence:  

Samples are pipetted, either manual or automatically, into the BOD bottles and the identity and the dilutions are entered or downloaded from LIMS into the sample table. Bottles are placed in the racks and placed on the Robotic Analyzer. Analyzer is started by operator. The bottle is decapped and filled with Nitrification inhibitor (ATU) and/or seed and dilution water. Sample is then stirred and the initial Oxygen value is measured. The bottle is capped and the Oxygen probe and stirrer are rinsed before going to the next sample. The same procedure is followed until a value is recorded for all samples. The sample racks are placed in a 20°C incubator for 5 days. After incubation the racks are placed on the Robotic analyzer. The operator starts the analyzer again. The bottle is de-capped. The sample is stirred and the final Oxygen value is measured. The BOD value is calculated. The bottle is capped. This procedure is repeated until all samples are measured. The data can be presented on screen, printed or converted to a file compatible with other software and LIMS’s.

Steps of Automation

• Pipetting of the sample
• pH setting of the sample
• Addition of Nitrification inhibitor (ATU) and/or Seed
• Addition of dilution water
• Sample homogenization
• Measurement of initial Dissolved Oxygen value (DO1)
• Probe/stirrer rinsing between each measurement
• Bottle capping/de-capping
• Measurement of final DO2 value
• Calculation of BOD according required regulations

If there is a requirement for other analyses such as pH, Conductivity, Alkalinity and Turbidity then these methods can be combined with BOD on the same robot.

SP2000 BOD analyzer movie

COD

Chemical Oxygen Demand (COD) analysis is commonly used to determine the amount of organic pollutants found in surface water and waste water. The COD value is a useful indicator for measuring the water quality. Skalar’s SP2000 analyzers can be configured to automate  COD according to the sealed tube (ST-COD) method ISO 15705 and EPA 410.4 or to the classical titration method ISO 6060

1. ST-COD according to ISO 15705 / EPA 410.4

The ST-COD method is based on exactly the same reaction as described in the classical method, but instead of titration, a photometric detection is used. An advantage of the ST-COD method is the use of pre-prepared tubes, which minimize handling of toxic and hazardous reagents.

The SP2000 ST-COD analyzer

The analyzer consists of a XYZ sample handling system and is equipped with removable sample tube- and test tube racks, so additional sample loads can be easily prepared and inserted during the analysis run. The analyzer can be built to accommodate 24 up to 336 tubes in one batch. The analyzer has a robotic arm with two manipulators, one with a gripper and the other with sample needle and stirrer. Furthermore the analyzer has a (de)-capping device, a vertical shaker for easily dissolving solid reagents of the test kit and mixing the sample, as well as a rotating shaker for mixing the tubes before measuring. The analyzer has a compartment for additional reagents and if digestion is required the analyzer with two temperature adjustable thermo reactors is available. A photometer takes care of the measurement and the results are sent to the RoboticAccess™ software for further data handling and control.

The analyzers can be used with commercial available or self-made COD reaction tubes and is compatible with several photometers. Besides single test kit analysis such as described above the same platform can be used to combine COD analysis with other test kit applications such as Total Phosphate, Total Nitrogen etc. For example a combination of 48 COD, 24 Total Phosphate and 12 Total Nitrogen tubes in one batch.

A typical ST-COD analysis sequence:

Tubes are placed in the sample racks and transferred to the analyzer. The analyzer picks-up the tubes and the tubes are decapped. The sample is automatically pipetted into the reaction tubes. The reaction tubes are capped and transported to the vertical shaker. The reaction tubes are mixed and transferred to the reactor, where they are heated for two hours at 150 °C. The analyzer keeps track of the reaction time. When the reaction is completed the analyzer places the tubes in a sample rack to cool down to 60 °C, after which they are mixed whilst still being warm. When the samples are cooled down to ambient temperature they will be measured with a photometric detector at the required wavelength. The concentration is shown in the result screen of the software and the data can be transported to the LIMS system.

Steps of Automation

• Sample tube pick up
• Sample tube (de) capping
• Pipetting of the sample
• Sample mixing
• Sample positioning in heating reactor
• Sample heating for two hours at 150˚C
• Sample transfer to cool down rack
• Sample homogenizing
• Measurement COD concentration

2. COD according to ISO 6060

The SP2000 analyzer provides the automation of the classical COD method. After refluxing, the samples are cooled and are automatically titrated with iron-ammonium-sulfate to determine the excess of oxidizing agent.

The SP2000 COD analyzer

The analyzer has got a XYZ sample handling system and can be built with 4 up to 6 interchangeable sample racks with 20 positions each. The samples can remain in the same vials from digestion to titration. Furthermore the analyzer is equipped with a titrator, burette tip, probe and stirrer. The analyzer can be equipped with two titrators for range expansion, without changing the burette.

A typical COD analysis sequence:

Test Kits

Ready-to-use photometric tests are being used by many water laboratories around the world. A lot of suppliers offer these kits for many important parameters in water and wastewater analysis such as COD, Total Phosphate, Total Nitrogen, Ammonium, Nitrite etc. The usage of these kits is simple and safe, but still requires many different manual handling steps in the analysis procedure such as sample pipetting, (un)screwing of the tube caps and tube transfer. Especially when the sample amount increases or different parameters have to be analyzed; this process can be very tedious and time consuming. In response to this, Skalar has developed the new SP2000 robotic analyzer series for the complete automation of ready-to-use test kits. The analyzer is a fully automated solution for handling the sample pipetting, mixing, heating, cooling and measurement of any water or wastewater sample using photometric test kits.

The SP2000 robot can be built to accommodate 24 up to 336 tubes in one batch. The analyzer can process multiple applications in parallel or sequentially at an individual sample level. The analyzer can be configured with a second robotic arm to increase sample throughput by using a second gripper and sample needle and stirrer or to perform additional tasks such as test kit analysis combined with another application such as BOD. The platform has protective front and side covers to comply with applicable CE regulations and is powered by the very practical and flexible RoboticAccess™ software package, which includes pre-installed application files containing the analysis sequence, user definable sample table set up and extensive QC features. The analyzer can handle test kits and photometers from different suppliers.

pH / EC / Titrations / Turbidity / Color / ISE

The Skalar Robotic Analyzers can handle the automation of pH, conductivity, titrations, turbidity and color combined into one system for sequential or simultaneous analysis. Custom-made configurations are available to meet the requirements of any laboratory. These include the choice of various applications, the running sequence and the integration of a variety of sample racks and sample beakers.

When the system is configured for the analysis of drinking water, pH, EC, Alkalinity and Turbidity, it can be user-defined whether the applications are required to run simultaneously or sequentially. The system also allows the selection of the analysis performed on each individual sample.

There is a special configuration of the  SP2000 platform for pH measurement in well plates. The manipulator carries two separate special pH electrodes for simultaneous pH measurement of two different samples. The analyzer has a sample capacity of up to 768 samples per batch, distributed over eight 96-well-plates.

Depending on the application, calibration of the instrumentation can be performed automatically to ensure an accurate performance. Quality control checks and standards can be placed in between samples and probes can be re-calibrated automatically.

This flexible design of the Skalar SP2000 Robotic Analyzers allows combinations of various applications like Alkalinity, Dissolved oxygen, Conductivity, Color, pH, Hardness, Turbidity, Titrations, Ion Selective Electrode (ISE) in one economical system.

Soil-pH

The pH of soil influences the availability of minerals for the plants. Each plant has a certain pH at which it is optimally grown and produced. The pH analysis is the most common parameter carried out on soil samples. Specialized laboratories analyze the soil and provide farmers with the required information. Based on the analysis results, the best method can be selected to improve the soil quality resulting in increased crop quantities and cost reduction.

The SP2000 pH-soil analyzer

The Robotic Analyzer can be configured for measurement of soil-pH in water extracts as well as in KCl, CaCl₂ or other extracts. The procedure includes the automatic calibration of the probe and addition of extraction solutions, automatic stirring, pre-defined sample settling times and measurement. The analyzer can have a capacity of up to 792 containers (50 ml). For extremely large batches the analyzer can be configured with two robotic arms each with multiple pH electrode configurations, up to a total of 8 electrodes.

A typical soil-pH analysis sequence:

After weighing, the samples are placed in a rack. The racks are transferred to the analyzer. The analyzer adds extraction solution and stirs all the samples. Between each operation the analyzer rinses the probe. After a pre-defined settling period the samples are again stirred. The pH value of each sample is measured. The measured values of each sample is calculated and stored.

In addition to pH analysis, also parameters such as conductivity (EC), can be added to the soil-pH configuration.

Steps of Automation

• Addition of extraction solution
• Sample stirring
• Automatic probe calibration
• Probe rinsing
• Measurement of pH
• Result calculation

Clay fraction

Classification of soil is important for environmental control and construction purposes. Soil classification is based on several factors such as absorption, the ability to shrink or swell, water retention and permeability. Most of these factors independently correlate with the particle size of the soil. The clay fraction, the smallest fraction (0-2 micron), is indispensable in assessing soil quality. The clay fraction is measured according to for instance ISO 11277 and allows the soil to be categorized within stated classes.

The analysis is carried out in three steps:

1. Weighing the sample and separating the fractions
2. Removal of Organic Matter and Carbonates
3. Determination of the clay fraction

Skalar has developed a concept to automate the second and third step in this process using a Skalar Robotic analyzer. Automation of these steps is of particular interest because they  can now be carried out fully automatic and with precise timing and pick up heights.

A typical Organic Matter/Carbonates removal sequence:

After weighing, the samples are placed in a bottle. The bottles are placed in the Skalar SP50 Robotic analyzer and an amount of water is added. The bottles with sample are heated until the boiling point has been reached. A sample is boiled for 30 min. During heating and boiling every 30 min, 5 ml of hydrogen peroxide is added to remove the organic matter. Afterwards the sample is cooled down and the same process is started but now with the addition of hydro chloric acid to remove the carbonates. During the complete process water is added in intervals to avoid excessive boiling of the sample.

Steps of Automation

• Removal of Carbonates
• Removal of Organic matter
• Rinsing of the sample

A typical Clay fraction analysis sequence:The sample is transferred into a volumetric cylinder of 500/1000 ml. The system, a Skalar SP2000 robotic analyzer automatically adds Sodium pyrophosphate solution and brings the suspension to volume by adding distilled water. During a user-definable time, the sample is homogenized. After a settling period of several hours a fraction of the suspension is taken at a predefined depth from the cylinder and this fraction is transferred to an evaporation dish by the system. After drying the remainder of the sample is weighed and the Clay fraction is calculated via the software.This procedure can also be performed unattended allowing for overnight operation. In addition, it is also possible to determine other fractions.

Steps of Automation

• Addition of pyrophosphate
• Addition of dilution water
• Sample homogenizing
• Sample take up
• Sample transferring
• Sample dispensing
• Sample drying in aluminum cup