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