1. Polarity index Sohim M.Pharma 1st year Presented to Jayanta Kumar Maji
Presented to Jayanta Kumar Maji
At Gujarat Ayurved University
On April-2015

2. Content INTRODUCTION DIELECTRIC CONSTANT POLARITY
SOLVENT POLARITY CHART
SOLVENT POLARITY INDEX TABLE
APPLICATION OF POLARITY INDEX

3. INTRODUCTION
Extracted compound is based on the type of solvents used.
Polar solvent isolates polar compound and non-polar solvent extracts non-polar compound.
Different solvents yield different extracts and extract composition.

4. DIELECTRIC CONSTANT
Dielectric constant: a measure of a solvent’s ability to insulate opposite charges from one another
The most common measure of solvent polarity is dielectric constant

5. POLARITY Solvents are classified as polar and nonpolar.
The greater the value of the dielectric constant of a
Solvent , the smaller the interaction between ions of
opposite charge dissolved in that solvent.
Polar Solvent: Dielectric constant > 15
Non-Polar Solvent: Dielectric constant < 15

7. Solvent-Solvent Interactions:
Liquids having similar dielectric constants (e.g., H2O and acetonitrile) are likely to be miscible (soluble in all proportions) while liquids having very different K values
(e.g., H2O and hexane) are normally immiscible
(insoluble in each other).
The general rule is ‘like dissolves like’.

8. SOLVENT’S CHOICE A property of a good solvent in plant extraction:
Low toxicity
Ease of evaporation at low heat
Promotion of rapid physiologic absorption of the
extract
Preservative action
Inability to cause the extract to complex or dissociate

9. SOLVENT POLARITY CHART

10. Solvent Polarity index table:
Dielectric Constant(K)
Refractive 20C
UV(nm) 1AU
B.P©
M.P©
Viscosity(c poise)
Solubility in Water (%w/w)
Density (g/ml)
Acetic acid
6.2
1.372
230
118
-17
1.26
100
1.04
Acetone
5.1
1.359
330 56
0.32
Acetonitrile
5.8
3.6
1.344
190 82
-45
0.37
0.79
Ammonia 23
0.69
Benzene
2.7
2.3
1.501
280 80 5
0.65
0.18
0.88
n-Butanol 4
1.394
254
125
0.73
0.43
Butyl acetate
3.9
1.399
215
2.98
7.81

11. Carbon tetrachloride
1.6 2
1.466
263 77
-23
0.97
0.08
1.59
Chloroform
4.1
4.8
1.446
245 61
-64
0.57
0.815
1.48
Cyclohexane
0.2
1.426
200 81 1
0.01
1,2-Dichloroethane
3.5
1.444
225 84
0.79
0.81
Dichloromethane
3.1
1.424
235 41
0.44
Dimethylether 21 56
-95
Dimethylformamide
6.4
1.431
268
155
0.92
100
Dimethylsulfoxide
7.2 47
1.478
189 18
1.1
Dioxane
1.422
215
101
1.54

12. Ethanol
5.2 24
1.36
210 78
-117
1.2
100
0.79
Ethyl acetate
4.4
1.372
260 77
0.45
8.7
Di-Ethyl Ether
2.8
1.353
220 35
0.32
6.89
Formamide
110
193 3
1.13
Heptane
1.387
200 98
0.39
0.0003
Hexane 2
1.375 69
-95
0.33
0.001
0.66
Hydrogen Flouride 84 20
-83
1.002
Methanol
5.1 33
1.329
205 65
-94
0.6
Methyl-t-Butyl ether
2.5
1.369 55
0.27
4.8
Methyl Ethyl Ketone
4.7
1.379
329 80
Pentane
1.358 36
0.23
0.004
n-propanol 4
1.384 97
2.27
Iso-propanol
3.9
1.377 82
2.3
Di-Isopropyl ether
2.2
1.368 68
0.37

13. Sulfuric acid
101
270 10
1.83
Tetrahydrofuran 4
7.6
1.407
215 65
-65
0.55
100
0.89
Toluene
2.4
1.496
285
111
0.59
0.051
Tichloroethylene 1
1.477
273 87
0.57
0.11
Water 9 81
1.333
200
0.998
Xylene
2.5
1.5
290
139
0.61
0.018

14. Application of polarity index:
Solvent system designing:
Snyder Prism Algorithm

15. Thank You