Robotic Fluoride Analysis

Metrohm have produced the first off-the-shelf, dedicated Robotic Fluoride Analyser. Historically, bench-top fluoride analysis can be very time consuming.

With the Metrohm 855 Robotic Fluoride Analyzer, the analyst no longer must carry out the following;

• Ensure the Ion Selective Electrode (ISE) is conditioned and stored
• correctly
• Calibrate the ion meter with standards before measurement
• Manually add a exact volume of TISAB (Total Ionic Strength
• Adjustment Buffer)
• Rinse and condition electrode between each measurement

For routine high volume rapid fluoride determination, the 855 Fluoride Analyzer is the perfect solution. Up to 59 sample positions. Everything has been taken into consideration. The measurement is achieved by standard addition and the TISAB is added automatically by the 855.

Applications for the system

Some recent examples of samples the system has been used for indicate the possible range of analysis

• Lanfill leachates, 0.1ppm and above
• red wine 0.2 ppm,
• cooking salt 52ppm
• mouth-wash 250ppm
• toothpaste 1300 ppm

Work is carried out at a fixed ionic strength in the fluoride determination. The sample is treated with an exactly defined volume of TISAB solution (TISAB = Total Ionic Strength Adjustment Buffer). Previously this buffer had to be added manually. An additional Dosino is incorporated in the Robotic Fluoride Analyzer to carry out the addition of this buffer. Thanks to the flexible programming the TISAB solution is added fully automatically before the sample is analyzed with an accuracy and precision that is not influenced by the user. A second Dosino is used for standard addition to achieve a measurement. Mounted directly on the reagent bottle, the Dosino is the perfect way of dosing and space-saving. The sensor combination of crystal membrane fluoride ISE and a <Long Life> ISE Reference electrode leaves nothing to be desired. The perfectly matched construction of this electrode pair can determine the fluoride content of the sample precisly, even at a low sensor immersion depth.

At low ion concentrations and low ionic strengths and most importantly for repeated determinations in automated systems, a stable, reproducible reference potential is crucial. The 6.0750.100 Long Life reference Electrode is has a fixed ground-joint diaphragm which provides a constant electrolyte flow, this is very important as the ionic strength and stirring rate have a minor influence on results. In addition to the fluoride measurement accessories, the 855 Robotic Analyzer comes with an application package containing all the necessary instructions and flouride methods including many determination examples in the database. The methods provided are already included in the tiamo software as templates. The data produced is managed in a well laid out and easy to use database. The top-quality tiamo software offers everything required for high sample throughput- and more. From flexible method parameters up to data storage in a professional database. IF-THEN-ELSE links, complex calculations, user administration and working under FDA-conditions are easy with this modern titration software.

In Summary

• Up to 59 samples per rack
• The 855 adds the standard and TISAB
• The 855, rinses the electrodes after every determination

The 855 stores the electrode in the correct solution between runs There is state-of -the-art software control and data storage. The integration of the Ion Meter, Sample Processor and Dosinos ensure little bech-space is taken up.