[Ibin-Huan]

Hello

Uv-Visible spectrophotometer and photometric measurements are useful for locating the end point of titration. According to this info, I need more information about it and even experiments.

Thank you in edvance
chemist777@yahoo.com

[marquis]

Usually, an automatic titrimeter will use special optics to detect an endpoint by UV/VIS.  A normal UV vis doesn't have the special optics and is difficult to use for the same purpose.

I making an assumption that may be wrong.  Please let me know if it is. I think you want to use a uv vis to detect indicator concentrations that would normally be hard to see. 

A normal UV/vis has a 1 cm pathlength cell (the quartz cell itself is usually 1 cm by 1 cm by 3 or 4 cm).  This means the total volume of the cell is 3 or 4 mls. You have to transfer the unknown solution into the cell and back to the titrating beaker several times using this approach.  It would also lead to a lot of potential errors.

Another option would be to use a 10 cm path length cell.  This would bring your total volume up to 30 or 40 ml.  You could set the entire titration up in the 10 cm pathlength cell.  Still a difficult volume for a titration, but much better.

A third option is a "sipper" accessory for the UV/VIS.  These can be set up to constantly circulate the solution whose spectra is measured.  The trouble is, you don't see a lot of "sipper" equiped instruments.

Hope this helps and good luck.