With the new Spectrosense electrode Metrohm UK can carry out high throughput metal analysis using photometric endpoint recognition
Traditionally metals such as zinc (Zn) have been titrated using EDTA and observing a colour indicator change to signify the end-point (such as Xylenol Orange for zinc).
Masking agents to eliminate interfering metals and buffers are added to create the ideal testing conditions.
This manual technique can be time consuming and results can vary between analysts.
A technique to automate this would free up analysts' time and eliminate any different results generated by different analysts.
The new Metrosensor Spectrosense allows users to benefit from the advantages of automated photometric titration in an optimal way.
Depending on the application, choose one of the two wavelengths available: 523nm or 610nm.
Modern LEDs serve as the light source; they have an average operating time of 50,000 hours and their light intensity remains high even after long operating times.
Because the Spectrosense can be connected directly to a titrator and mounted on a sample processor Metrohm have made a high throughput version of this technique very simple.
Individual sample racks can accommodate up to 100 samples and the system elegantly controlled by Tiamo controlling software.
Metrohm UK has automated Zn and Pb analysis using the Spectrosense.
It was found that the Spectrosense technique became invaluable when it became obvious that for one particular sample the sample matrix affected the results when using an ion selective electrode for titrations as there were other metals present that impacted on the results.
However, the Spectrosense method enabled the company to mirror the original manual analysis, using the prescribed masking solution and buffers while automating the analysis.
The results obtained were highly reproducible.
Titration with photometric endpoint recognition is applied in a large number of titration methods.
It can also used when potentiometric endpoint indication is not possible, when no suitable potentiometric indicator electrode is available, when an official method prescribes photometric indication, the electrode signal is disturbed by sample matrix effects, or one wishes to profit from the economical advantages offered by the photometric method compared to more expensive techniques, such as AAS or ICP-AES.
Easy handling, quick and precise measurements are of prime importance.
The new Spectrosense is not only outstandingly robust, it is also very easy to handle.
It can be connected to a Titrino or Titrando like an ordinary electrode.
Power is supplied from the stirrer connection of the Titrino or the MSB connection of the Titrando.
If required, an external power adapter can also be used.
To automate the metal analysis Metrohm UK used a Spectrosense Sensor, 836 Titrando, and an 815 Sample Processor all controlled by Tiamo software.
