Properties of Solvents on Various Sorbents

What's on this page?

Tables dealing with elution strength ( ) on silica and alumina, refractive index (ri), UV cutoff, viscosity, the Hildebrand solubility parameter (), the Snyder polarity index and boiling point (BP) of solvents are listed here. The data is sorted on:

The Excel (version 97) file containing all data  is available for download here.

 

(An alternative is offered at Reall, which displays solvent properties like the polarity ( on alumina), dielectric constant, dipole, boiling point, UV cutoff (at 10%), selectivity group and viscosity (cP at 20'C).

 

Solvent selection in isocratic and gradient HPLC

Hildebrand solvent scale
The Hildebrand solvent scale is a list of common solvents used in Liquid Chromatography in order of increasing energy of adsorption on alumina. The values are different from the values on silica gel or alumina, but the order is essentially the same. (Hildebrand solubility values in tables below ).

 

Selection of starting solvent
The starting solvent selected for a given separation can be chosen by matching the relative polarity of the solvent to that of the sample. This is done as a first approximation by selecting the solvent to match the most polar functional group on the sample molecule (e.g. alcohols for OH, amines for NH2, etc.). From this attempt, the separation can be refined by the following procedure:

  1. If the sample appears at the solvent front then the solvent is too polar to allow the adsorbent to retard the sample. Go to a solvent higher up (lower polarity) on the scale.

  2. Conversely if the sample does not appear in a reasonable time go to a solvent or solvent blend lower down (higher polarity) on the scale.

Solvent blends
Solvent blends are most useful when they are composed of pairs, which differ in adsorption energy by no more than 100%. (Example: propanol at energy 0.82 and chloroform at energy 0.40.)

 

Solvent gradients
Solvent gradients should be generated on the same basis of no more than doubling the energy of the starting solvent. The range is more than sufficient for most if not all separation problems.
When changing solvents or when regenerating after a gradient, a minimum of 5-10 column volumes of the new starting solvent should flow through the system before making another sample injection. For a estimation of your column volume, click here.

 

Solvent miscibility
Normally, solvents are completely miscible if they are on the same half of the scale (from 0 to 1). In other words, all solvents on the upper half of the scale are completely miscible, or all on the bottom half are miscible with each other, and all solvents from the center half (1/4 to 3/4) are mutually miscible. There are several "universal" solvents such as tetrahydrofuran and acetonitrile, which are miscible with almost all others except hexane and pentane. By far the most useful "rinsing, or cleanout" solvent is iso-propanol, which is miscible with all others at all concentration levels. A solvent miscibility table can be found elsewhere on this site.

 
The general separation problem
Change the solvent strength: In isocratic runs, increase or decrease the modifier concentration with a few per cent. In gradient runs, change the gradient steepness.

Change the column temperature  10C.

Change the pH of the mobile phase 0.5 pH units.

 

Elution strength

Al2O3

SiO2

solvent

ri

UV cutoff

(cP) at 20C

Hildebrand solubility parameter

polarity index (Snyder)

BP (C)

0.01 0.01

i-octane

1.404

197-210

0.5 7 0.4 99.2
0.01 0.03

n-hexane

1.375 195 0.313 7.3 0 68.9
0.04 0.04

cyclohexane

1.427 200 0.98 8.2 0 80.7
0.04

 

n-decane

1.412 210 0.92 7.8 0.3 174.1
0.18 0.12

carbon tetrachloride

1.466 265 0.97 8.6 1.7 76.5
0.28 0.22

i-propyl ether

1.368 220

0.33-0.37

7.3 2.2 68.3
0.29 0.23

toluene

1.496 285 0.59 8.9 2.3 101.6
0.32 0.25

benzene

1.501 280 0.65 9.2 3 80.1

0.36-0.4

0.26

chloroform

1.443 245 0.57 9.2

3.4-4.4

61.2
0.4 0.32

dichloromethane

1.424 232 0.44 9.6 3.4 40
0.42 0.32

methylene chloride

1.424 233 0.44 9.7 3.4 39.8
0.45 0.35

tetrahydrofuran

1.408

212-230

0.55 9.1 4.2 66
0.49 0.38

ethylene dichloride

1.445 230 0.79 9.7 3.7 83.5
0.51 0.39

methyl ethyl ketone (MEK)

1.379 330 0.43 9.3 4.5 80

0.56-0.58

0.47-0.53

acetone

1.359 330 0.32 9.6 5.4 56.3

0.55-0.65

0.5

acetonitrile

1.344 190 0.37 11.7 6.2 81.6
0.58

0.38-0.48

ethyl acetate

1.37 256

0.46-0.47

9.1 4.3 77.1
0.6 0.46

methyl acetate

1.362 260

0.37-0.45

9.2 4.4 56.3
0.62 0.41

dimethyl sulfoxide

1.478

 

2.24 12.8 6.5 189
0.71

 

pyridine

1.51

305-330

0.94 10.7 5.3 115.3
0.74

 

methoxyethanol, 2-

1.401 220 1.72

 

5.7 124.6
0.82

 

propanol, 2-

1.38

210+

2.35

 

4.3

82.4-117.7

0.88 0.68

ethanol

1.361

205-210

1.2 12 5.2 78.3
0.95 0.73

methanol

1.329 205 0.6 13.7 6.6 64.7

large

 

acetic acid

1.372 210

1.1-1.26

12.4 6.2 117.9

large

 

water

1.333 180 1 21 9 100
 

Snyder polarity index 

polarity index (Snyder)

solvent

ri

UV cutoff

(cP) at 20C

Hildebrand solubility parameter

SiO2

Al2O3

BP (C)

0

cyclohexane

1.427

200

0.98

8.2

0.04

0.04

80.7

0

n-hexane

1.375

195

0.313

7.3

0.03

0.01

68.9

0.3

n-decane

1.412

210

0.92

7.8

 

0.04

174.1

0.4

i-octane

1.404

197-210

0.5

7

0.01

0.01

99.2

0.4

octane

1.395

 

0.5

 

 

 

99.2

1.7

butyl ether

 

 

0.7

 

 

 

142.2

1.7

carbon tetrachloride

1.466

265

0.97

8.6

0.12

0.18

76.5

1.8

triethyl amine

1.401

 

0.38

 

 

 

89.5

2.2

i-propyl ether

1.368

220

0.33-0.37

7.3

0.22

0.28

68.3

2.3

toluene

1.496

285

0.59

8.9

0.23

0.29

101.6

2.4

xylene, p-

 

 

0.7

 

 

 

138

2.9

t-butyl methyl ether

1.370

210

0.27

 

0.35

 

55.2

3

benzene

1.501

280

0.65

9.2

0.25

0.32

80.1

3.3

benzyl ether

 

 

5.33

 

 

 

288.3

3.4

dichloromethane

1.424

232

0.44

9.6

0.32

0.4

40

3.4

methylene chloride

1.424

233

0.44

9.7

0.32

0.42

39.8

3.4-4.4

chloroform

1.443

245

0.57

9.2

0.26

0.36-0.4

61.2

3.7

dichloroethane

  

 

 

 

 

 

83.4

3.7

ethylene dichloride

1.445

230

0.79

9.7

0.38

0.49

83.5

3.9

butanol, 1-

 

 

 

 

 

 

117.2

3.9

i-butyl alcohol

  

 

3

 

 

 

117.7

4.2

tetrahydrofuran

1.408

212-230

0.55

9.1

0.35

0.45

66

4.3

ethyl acetate

1.370

256

0.46-0.47

9.1

0.38-0.48

0.58

77.1

4.3

propanol, 1-

  

 

2.3

 

 

 

97.2

4.3

propanol, 2-

1.380

210+

2.35

 

 

0.82

82.4-117.7

4.4

methyl acetate

1.362

260

0.37-0.45

9.2

0.46

0.6

56.3

4.5

cyclohexanone

  

 

2.24

 

   

155.7

4.5

methyl ethyl ketone (MEK)

1.379

330

0.43

9.3

0.39

0.51

80

4.5

nitrobenzene

  

 

2.03

 

 

 

210.8

4.6

benzonitrile

  

 

1.22

 

 

 

191.1

4.8

dioxane, 1,4-

  

 

 

 

 

 

101

4.8

dioxane, p

 

 

1.54

 

 

 

101.3

5.2

ethanol

1.361

205-210

1.2

12

0.68

0.88

78.3

5.3

nitroethane

1.392

380

0.68

 

 

 

114

5.3

pyridine

1.510

305-330

0.94

10.7

 

0.71

115.3

5.4

acetone

1.359

330

0.32

9.6

0.47-0.53

0.56-0.58

56.3

5.5

benzyl alcohol

  

 

5.8

 

 

 

205.5

5.7

methoxyethanol, 2-

1.401

220

1.72

 

 

0.74

124.6

6.2

acetic acid

1.372

210

1.1-1.26

12.4

 

large

117.9

6.2

acetonitrile

1.344

190

0.37

11.7

0.5

0.55-0.65

81.6

6.4

dimethyl formamide, N,N-

1.431

268

0.90-0.92

11.5

 

 

153

6.5

dimethyl sulfoxide

1.478

 

2.24

12.8

0.41

0.62

189

6.6

methanol

1.329

205

0.6

13.7

0.73

0.95

64.7

7.3

formamide

1.450

210

3.3-3.76

 

 

 

210.5

9

water

1.333

180

1

21

 

large

100

 

Solvent

solvent

ri

UV cutoff

(cP) at 20C

Hildebrand solubility parameter

SiO2

Al2O3

polarity index (Snyder)

BP (C)

acetaldehyde diethyl acetal

1.379

 

 

 

 

 

 

 

acetaldehyde diethyl acetal

1.379

 

 

 

 

 

 

 

acetic acid

1.372

210

1.1-1.26

12.4

 

large

6.2

117.9

acetic anhydride

1.389

 

 

 

 

 

 

 

acetone

1.359

330

0.32

9.6

0.47-0.53

0.56-0.58

5.4

56.3

acetonitrile

1.344

190

0.37

11.7

0.5

0.55-0.65

6.2

81.6

benzene

1.501

280

0.65

9.2

0.25

0.32

3

80.1

benzonitrile

 

 

1.22

 

 

 

4.6

191.1

benzyl alcohol

 

 

5.8

 

 

 

5.5

205.5

benzyl ether

 

 

5.33

 

 

 

3.3

288.3

butanol, 1-

 

 

 

 

 

 

3.9

117.2

butanol, 2-

1.395

 

 

 

 

 

 

 

butanone, 2-

1.377

 

 

 

 

 

 

 

butyl acetate

1.392

 

 

 

 

 

 

 

butyl acetate, sec-

1.387

 

 

 

 

 

 

 

butyl ether

 

 

0.7

 

 

 

1.7

142.2

butyl ethyl ether

1.380

 

 

 

 

 

 

 

butyl formate

1.387

 

 

 

 

 

 

 

butylamine, 2-

1.390

 

 

 

 

 

 

 

butyraldehyde

1.378

 

 

 

 

 

 

 

butyric acid

1.396

 

 

 

 

 

 

 

butyronitrile

1.382

 

 

 

 

 

 

 

carbon tetrachloride

1.466

265

0.97

8.6

0.12

0.18

1.7

76.5

chlorobutane, 2-

1.395

 

 

 

 

 

 

 

chloroform

1.443

245

0.57

9.2

0.26

0.36-0.4

3.4-4.4

61.2

chloropropane, 1-

1.386

 

 

 

 

 

 

 

chloropropane, 2-

1.376

 

 

 

 

 

 

 

cyclohexane

1.427

200

0.98

8.2

0.04

0.04

0

80.7

cyclohexanone

 

 

2.24

 

 

 

4.5

155.7

dichloroethane

 

 

 

 

 

 

3.7

83.4

dichloromethane

1.424

232

0.44

9.6

0.32

0.4

3.4

40

diethyl carbonate

1.385

 

 

 

 

 

 

 

di-isopropylamine

1.390

 

 

 

 

 

 

 

dimethyl formamide, N,N-

1.431

268

0.90-0.92

11.5

 

 

6.4

153

dimethyl sulfoxide

1.478

 

2.24

12.8

0.41

0.62

6.5

189

dimethylbutane, 2,2-

1.369

 

 

 

 

 

 

 

dimethylbutane, 2,3-

1.372

 

 

 

 

 

 

 

dimethylpentane, 2,3-

1.389

 

 

 

 

 

 

 

dimethylpentane, 2,4-

1.379

 

 

 

 

 

 

 

dioxane, 1,4-

 

 

 

 

 

 

4.8

101

dioxane, p

 

 

1.54

 

 

 

4.8

101.3

dodecafluoro-1-hepatanol

1.316

 

 

 

 

 

 

 

ethanol

1.361

205-210

1.2

12

0.68

0.88

5.2

78.3

ethyl acetate

1.370

256

0.46-0.47

9.1

0.38-0.48

0.58

4.3

77.1

ethyl ether

1.352

 

 

 

 

 

 

 

ethyl formate

1.358

 

 

 

 

 

 

 

ethyl propionate

1.382

 

 

 

 

 

 

 

ethylene dichloride

1.445

230

0.79

9.7

0.38

0.49

3.7

83.5

formamide

1.450

210

3.3-3.76

 

 

 

 

pyridine

1.510

305-330

0.94

10.7

 

0.71

5.3

115.3

t-butanol

1.385

 

 

 

 

 

 

 

t-butyl methyl ether

1.370

210

0.27

 

0.35

 

2.9

55.2

tetrahydrofuran

1.408

212-230

0.55

9.1

0.35

0.45

4.2

66

toluene

1.496

285

0.59

8.9

0.23

0.29

2.3

101.6

triethyl amine

1.401

 

0.38

 

 

 

1.8

89.5

trifluoroacetic acid

1.283

 

 

 

 

 

 

 

trifluoroethanol

1.290

 

 

 

 

 

 

 

trifluoropropanol

1.381

 

 

 

 

 

 

 

trimethylbutane, 2,2,3-

1.387

 

 

 

 

 

 

 

trimethylhexane, 2,2,5-

1.397

 

 

 

 

 

 

 

trimethylpentane, 2,2,4-

1.389

 

 

 

 

 

 

 

valeronitrile

1.395

 

 

 

 

 

 

 

water

1.333

180

1

21

 

large

9

100

xylene, p-

 

 

0.7

 

 

 

2.4

138

 
last update: augustus 11, 2007