Equilibrium Constants from Solution Spectrophotometric Data

The Windows® application HypSpec supercedes both Hyperquad2006 and pHab for the determination of equilibrium constants from spectrophotometric data as it combines and improves the functionality of both programs. It can process UV/visible, infrared, Raman, luminescence and fluorescence data, subject to the single requirement that the spectral intensity of each chemical species should be proportional to the concentration of that species in solution. The spectral data may be obtained by titration or from a set of individual solutions (batch data). There is an option to include pH measurements in addition with both titration and batch data. For only potentiometric data use Hyperquad2008.

References (View paper requires Acrobat reader):

Hyperquad: P. Gans, A. Sabatini and A. Vacca, Talanta, (1996), 43, 1739-1753. view paper

pHab: P. Gans, A. Sabatini and A. Vacca,, Annali di Chimica, (1999), 89, 45-49. view paper

The package includes 7 sets of sample data and related files. There is also a detailed Help file which has descriptions of all the program's functions.

Data preparation

  1. Model data. The "model" defines which chemical species are present in the solutions. The species are a) reagents and b) complexes formed from the reagents. The values of the equilibrium constants of the complexes must have been determined previously or estimated by reference to similar compounds. SC-database is useful for estimating stability constant values. There are no restrictions on model complexity.
  2. Create new project. A wizard-type procedure takes the user through all steps needed to create a new project. This includes importing data from ASCII (text) files produced by spectrophotometric instruments, or a composite text file created from those files.
  3. Edit the data if need be.
  4. Import any spectra which have been determined in other experiments
  5. Choose a weighting scheme
  6. Preliminary analysis.: Fit the experimental data interactively by adjusting the model

Stability constant refinement

Analysis of results

Ancillary functions

Ancillary functions can be used at any time

System requirements

HypSpec designed to run on a PC under the Windows95/98/NT/2000/XP/Vista operating systems. There are no specific system requirements, but a screen resolution greater than 800*600 pixels is desirable in order to permit interactive preliminary data fitting.

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