========================INTRODUCTION===============================
MATLAB based Simulation of Temperature Effects on ElectroPhoresis (STEEP) buffer calculator 

Developed by Anita Rogacs (2013), Supreet Singh Bahga (2010) and Moran Bercovici(2009)

Publications: 
1. Rogacs, A., Santiago, J.G., Temperature Effects on Electrophoresis, Analytical Chemistry, 2013, dx.doi.org/10.1021/ac400447k
2. Bahga, S.S.; Bercovici, M. and Santiago, J.G. Electrophoresis. 2010, 31 (5), 910-919.
3. Bercovici, M.; Lele, S.K. and Santiago, J.G. J. Chromatogr. A. 2009, 1216 (6), 1008-1018.

Interacing GUI was written by Jose Gutierrez and Anita Rogacs


========================ELECTROLYTE DATABASE======================
Includes the following electrolyte properties:
1. Valence
2. Electrophoretic mobility (m^2/V/s) @ 25 C
3. pK @ 25 C
4. deltaH (standard molar enthalphy of ionization) @ 25 C
5. deltaCp (standard molar heat capacity of ionization) @ 25 C

========================USER INPUT==================================
1. Concentration of each electrolyte species
2. Operating temperature in Celsius


========================STEEP OUTPUT================================ 
1. Electrolyte properties at specified operating temperature (valence, absolute mobility (viscosity and solvation corrected), pKa)

2. Background Electrolyte (BGE) Properties (@ 25 C and @ Operating temperature)
pH
Ionic Strength (M)
Conductivity (S/m)
Buffering Capacity (M)

3. Effective mobility of solution constituents (m^2/V/s) (@ 25 C and @ Operating temperature)


========================RUN DIRECTIONS==================

1) Open MATLAB

2) Move to the directory named "Calculator"

3) Run STEEPBufferCalculatorGUI.m
4) Click to species row in "Electrolyte Database" and click "Add" to add species to BGE table. 
5) Specify concentration of each species in 2nd column of BGE table  
6) Specify operating temperature
7) Click Calculate
8) To export data from tables, hit EXPORT. User defined Input Table (Solution Composition), operating temperature, electrolyte properties at the operating temperature (effective mobility, absolute mobility, pKa), and solution properties (pH, Ionic Strength, Conductivity, Buffering Capacity) will be exported to folder named Data stored in same workspace as the GUI. 

9) To add a customs species, add one species from the database and change its properties in Solution Composition table.

=======================SPECIAL NOTES=====================
Electrolyte database (located \Calculator\Database) contains over 100 species.
--------------Column "ref" letter codes indicate the following:---------------

'g': Values of pK, deltaH and delta Cp were obtained from the following reference:
 Goldberg, R.N.; Kishore, N. and Lennen, R.M. J. Phys. Chem. Ref. Data. 2002, 31 (2), 231-370.

'c':  Values of pK, deltaH (and deltaCp when available) were obtained from the following reference:
Christensen, J.J.; Hansen, L.D. and Izatt, R.M. Handbook of proton ionization heats and related thermodynamic quantities. Wiley New York: 1976.

For most electrolytes, van't Hoff based predictions are sufficiently accurate. For discussion on the accuracy of pK prediction with temperature via van't Hoff (using deltaH alone) versus Clark-Glew (using deltaH and deltaCp), see references:

Fukada, H. and Takahashi, K. Proteins. 1998, 33 (2), 159-166
Rogacs, A., Santiago, J.G., Temperature Effects on Electrophoresis, Analytical Chemistry, 2013, dx.doi.org/10.1021/ac400447k

's': deltaH and deltaCp values are not available. 
Note: we included a handful common strong electrolytes (e.g.: potassium and sodium hydroxide) for which we do not have these properties available.  Since the pK of strong electrolytes are (typically) are below 2 or above 12 pK, change in their pK (calculated using deltaH and deltaCp) will not effect their ionization and thus can be neglected in BGEs of moderate pH (4-10).

STEEP will launch a popup window displaying a message warning when such an electrolyte is selected. If the pH is far from the pK of this electrolyte, we recommend replacing NaN with 0 values and proceeding with the simulation. 


---------------------------Non-acid base reactions--------------------
STEEP does not model non-acid base reactions. 

For example, combination of Tris and boric acid consistently shows large discrepancies between model and measurements of conductivity and pH at all temperatures. Michov, which showed that Tris-borate buffers contain a cyclic complex compound of betainic structure, and a buffer with both  of these ions therefore does not obey the Henderson-Hasselbalch equation.

Therefore, we recommend that user validates all buffers by measuring the pH and/or the conductivity of the BGE elevated temperature.


References:
Michov, B.M. Electrophoresis. 1986, 7 (3), 150-151.
Rogacs, A., Santiago, J.G., Temperature Effects on Electrophoresis, Analytical Chemistry, 2013, dx.doi.org/10.1021/ac400447k


------------------------------------Database Modification----------------------------------------------------
Database can be modified in Excel, but make sure to save final spreadsheet in Excel 95 format to maintain compatibility with STEEP
http://www.mathworks.com/support/solutions/en/data/1-8JAYV8/?product=ML&solution=1-8JAYV8

----------------------------------Bypassing GUI ------------------------------------
Use function SampleSolution.m to develop custom code for more complex temperature simulation.


