HPLC designer by Hansen Solubility Parameter (HSP)

HSP Application note #50

2010.8.10

HSPiP Team Senior Developer, Dr. Hiroshi Yamamoto

The HPLC function implemented to HSPiP is completely different from the program introduced in User’s Forum articles.
I made program that can test HPLC retention time and design of solvents mixture.

Chromatography

The most popular column for HPLC is ODS column and this column contains Silica-gel covered by Octadecyl. When we insert some chemicals into this column, some chemicals dissolve to octadecyl alkyl chain deeply and some do not. So, highly interacted chemicals will delay to elute. Or some chemicals which are very easily dissolve to carrier liquid, elute very early.

We can evaluate these solubility with Hansen Solubility Parameters (HSP). Molecular size also play important role.

Pirika Java Demo Applet design Carrier Solvent. HPLCDemo is available here.

I will explain how to use this program with antioxidants example.
Please refer to original article for more detail.

What we want to do with this example is 2 and 3 peak resolution much higher.
Let’s calculate HSP of 2 antioxidants.

<p>Please Use HTML5 Browser</p>

If you draw several molecules and calculate each molecules' properties, program will simulate Retention Time (RT) of OSD column for HPLC. If you want to know how to draw molecules, please refer to PowerTools applications. I have full version of this HPLC RT simulation program at PowerTools+ Applications.

Hansen Solubility Parameters (HSP)

Hansen Solubility Parameters(HSP) were developed by Charles M. Hansen as a way of predicting if one material will dissolve in another and form a solution. They are based on the idea that "like dissolves like" where one molecule is defined as being 'like' another if it bonds to itself in a similar way.
Specifically, each molecule is given three Hansen parameters, each generally measured in MPa0.5:
dD:The energy from dispersion bonds between molecules
dP:The energy from dipolar intermolecular force between molecules
dH:The energy from hydrogen bonds between molecules.
These three parameters can be treated as Vector for a point in three dimensions also known as the Hansen space. The nearer two molecules HSP Vector are in this three dimensional space, the more likely they are to dissolve into each other.

What can perhaps be surprising is that one can assign HSP to so many different things. Gases like carbon dioxide, solids like carbon-60, sugar, and biological materials like human skin, depot fat, DNA, and even some proteins all have HSP. The list can be continued with drugs, polymers, plasticizers, and in fact any organic material and even many inorganic materials like salts. The only requirement for an experimental confirmation is that the material must behave differently in a sufficient number of test solvents upon contact.

Pirika JAVA Demo Applet calculate HSP. HSPLight is available here.
Please refer to e-Book of HSPiP if you want know more about HSP.
About the Power Tools that handle HSP more effectively.

If you have Smiles structure and HSPiP software, Y-MB function will calculate HSP immediately.

Smiles(Simplified Molecular Input Line Entry Syntax)

SMILES is a string obtained by printing the symbol nodes encountered in a depth-first tree traversal of a chemical graph.
"Organic subset" of B, C, N, O, P, S, F, Cl, Br, and I, brackets can be omitted.
Branches are described with parentheses, as in CCC(=O)O for propionic acid
Double and triple bonds are represented by the symbols '=' and '#'
Ring closure labels are used to indicate connectivity between non-adjacent atoms in the SMILES

Pirika JAVA Demo Applet getting Smiles. Draw2Smiles is available here.
Now we have Power Tool "Draw 2 Smiles", GUI HTML5 software on HSPiP ver. 4.

Y-MB Properties Estimation

Y-MB break Smiles into correspponding Functional Groups and Estimate various Properties. These estimation schemes are come from Pirika technologies.

Pirika JAVA Demo Applet calculate Properties. PirikaLight is available here.
Now we have Power Tool "Y-Predict", GUI HTML5 software on HSPiP ver. 4.

THBA[17.7, 8, 18.3] Mvol 157.7
TBHQ[17.3, 7.2, 16] MVol 161.5

If you run the JAVA applet, you will see the above panel.
Please input HSP and Volume for 2 molecules.
Then push Read mol button.
Program calculate Distance from Fixed Phase and Distance/Volume.

HSP Distance

To calculate the distance (Ra) between Hansen parameters in Hansen space the following formula is used:

HSP distance(Ra)={4*(dD1-dD2)2 + (dP1-dP2)2 +(dH1-dH2)2 }0.5

The values of Distance/Volume are 0.127 and 0.109 so retention time of these 2 molecules may very similar.
(If you want to calculate other compounds, put HSP and Volume and repeat calculation.)

If you want to separate these molecules more effectively, what you can do?
Enlarge column length, change temperature but maybe you want to design carrier solvent.

Original article, I explained like that.
Choose solvent mixture that is near to one molecule and far from the other.

Let’s try.
Select solvent from Combo box.
One is water and the other is acetonitrile.

Then program calculate HSP distance from carrier.
If you move slide bar, solvents ratio will change.
Please pay attention of Ratio (Ratio: Distance/Vol)

For example, if you set Water(20)-AN(80) then 2 molecules’ solubility to Carrier Solvent become equal. That mean bad for separation.
Water(65)-AN(35) to Water(49)-AN(51) separation will become maximum.

So, if you have the HSP value and Mol Volume for your target compound, you can easily calculate retention time and you can easily design solvent mixture.