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. (pdf)
pHab: P. Gans, A. Sabatini and A. Vacca,, Annali di Chimica, (1999), 89, 45-49. (pdf)
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.
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.
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.
Edit the data if need be.
Import any spectra which have been determined in other experiments
Choose a weighting scheme
Preliminary analysis.: Fit the experimental data interactively by adjusting the model
Stability constant refinement
The stability constant refinement is based on the the earlier programs, but has been extensively revised and re-written. The code that was previously contained in FORTRAN modules has been adapted for Visual Basic and incorporated into the main program. Stability constants are automatically updated after a successful refinement.
Analysis of results
The output viewer allows the results of a stability constant refinement to be viewed section by section.
Stepwise constants can be calculated.
Ancillary functions can be used at any time
factor analysis (aka principal component analysis)
viewing spectra at unit concentration
interactive fitting of experimental data
tables of concentrations and observed and calculated data can be viewed and copied to the clipboard
Some plots can be copied to the clipboard in vector-graphic format
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.