1. POLYSILOXANES Functional Groups
Si O R R
Name CH 3
Methyl
Phenyl
Cyanopropyl CH 2 CN CH 2 CF 3
Trifluoropropyl

2. STATIONARY PHASE % Substitution
% = # of sites on silicon atoms occupied
Balance is methyl

3. STATIONARY PHASE Polysiloxanes Methyl SubstitutedCH 3 n Si O
100 % methyl (DB-1)

4. POLYSILOXANES Phenyl methyl Substituted3 CH m n Si O
5% phenyl (DB-5) 35% phenyl (DB-35) 50% phenyl (DB-17)

5. DB-5MS Structure O O Si Si CH 3 CH 3 DB-5 Structure DB-5ms Structure
DB-5 5% Phenyl
DB-5ms 1.Increased stability 2.Different selectivity 3.Optimized to match DB-5

6. POLYSILOXANES Cyanopropyl methyl SubstitutedCH 3 C H 6 CN m n Si O
50% cyanopropyl (DB-23)

7. POLYSILOXANES Cyanopropylphenyl methyl Substituted3 H 6 CN n m Si O
6% cyanopropylphenyl (DB-1301) 14% cyanopropylphenyl (DB-1701) 50% cyanopropylphenyl (DB-225)

8. STATIONARY PHASE Poly(ethylene) Glycol
HO CH 2 CH O H n
100% PEG (DB-WAX) Less stable than polysiloxanes Unique separation characteristics

9. SELECTIVITY VS. POLARITY
Selectivity: Solute interactions and separations
Polarity: Physical characteristic of the stationary phase

10. POLARITY Nonpolar
100% Methyl (DB-1)
5% Phenyl (DB-5)

11. POLARITY Intermediate
35% Phenyl (DB-35)
50% Phenyl (DB-17)
6% Cyanopropylphenyl (DB-1301)
14% Cyanopropylphenyl (DB-1701)

12. POLARITY Polar 50% Cyanopropylphenyl (DB-225) 50% Cyanopropyl (DB-23)
50% Trifluoropropyl (DB-210)
Poly(ethylene) glycol (DB-WAX)

13. POLARITY Solubility And Retention2 4 6 8
Hexanol
C10
C12
100% Methyl (non-polar) 2 4 6 8
C10
C12
Hexanol
100% PEG (polar)
30 m x 0.32 mm ID, 0.25 um He at 35 cm/sec °C at 15°/min

14. SELECTIVITY Interaction Strengths
Phase
Dipersion
Dipole
H Bonding
Methyl
Strong
None
Phenyl
Weak
Cyanopropyl
Moderate
Trifluoropropyl
PEG

15. DISPERSION INTERACTION Kcal/mole2 4 6 8 10
Benzene
Phenol
C10
C12
8.1
11.9
10.9
DB-1 (non-polar)

16. DIPOLE INTERACTION Compounds With Dipole Differences
C=C Cl H
C=C Cl H
1,2-dichloroethylene
1,1-dichloroethylene

17. SELECTIVITY Interaction Strengths
Phase
Dipersion
Dipole
H Bonding
Methyl
Strong
None
Phenyl
Weak
Cyanopropyl
Moderate
Trifluoropropyl
PEG

18. COMPOUNDS Properties Compounds Polar Aromatic Hydrogen Bonding Dipole
Toluene no
yes
induced
Hexanol
Phenol
Decane
Naphthalene
Dodecane

19. 100% METHYL POLYSILOXANE 2 4 6 8 10 12 14 16 1 3 5
1. Toluene 2. Hexanol 3. Phenol 4. Decane (C10) 5. Naphthalene 6. Dodecane (C12)
Strong Dispersion No Dipole No H Bonding

20. 5% PHENYL 2 4 6 8 10 12 14 16
5% Phenyl 1 3
5,6
1. Toluene 2. Hexanol 3. Phenol 4. Decane (C10) 5. Naphthalene 6. Dodecane (C12) 2 4 6 8 10 12 14 16
100% Methyl 1 3 5
Strong Dispersion No Dipole Weak H Bonding

21. 50% PHENYL
100% Methyl 2 4 6 8 10 12 14 16 1 3 5
50% Phenyl
1. Toluene 2. Hexanol 3. Phenol 4. Decane (C10) 5. Naphthalene 6. Dodecane (C12)
Strong Dispersion No Dipole Weak H Bonding

22. 50% CYANOPROPYL
1. Toluene 2. Hexanol 3. Phenol 4. Decane (C10) 5. Naphthalene 6. Dodecane (C12) 2 4 6 8 10 12 14 16 1 5 3
50% Cyanopropyl
Strong Dispersion Strong Dipole Moderate H Bonding 2 4 6 8 10 12 14 16
100% Methyl 1 3 5

23. 14% CYANOPROPYLPHENYL
1. Toluene 2. Hexanol 3. Phenol 4. Decane (C10) 5. Naphthalene 6. Dodecane (C12) 2 4 6 8 10 12 14 16 1 3 5
14% Cyano- propylphenyl 2
Strong Dispersion None/Strong Dipole (Ph/CNPr) Weak/Moderate H Bonding (Ph/CNPr) 4 6 8 10 12 14 16
100% Methyl 1 3 5

24. 50% CYANOPROPYLPHENYL
1. Toluene 2. Hexanol 3. Phenol 4. Decane (C10) 5. Naphthalene 6. Dodecane (C12) 2 4 6 8 10 12 14 16 1 5 3
50% Cyano- propylphenyl
Strong Dispersion None/Strong Dipole (Ph/CNPr) Weak/Moderate H Bonding (Ph/CNPr) 2 4 6 8 10 12 14 16
100% Methyl 1 3 5

25. 100% POLYETHYLENE GLYCOL 2 4 6 8 10 12 14 16 1 5 3
100% PEG
1. Toluene 2. Hexanol 3. Phenol 4. Decane (C10) 5. Naphthalene 6. Dodecane (C12)
Strong Dispersion Strong Dipole Moderate H Bonding 2 4 6 8 10 12 14 16
100% Methyl 1 3 5

26. COLUMN DIAMETER Capillary Columns
I.D. (mm)
Common Name
0.53
Megabore
0.45
High speed Megabore
0.32
Wide
Narrow
0.18
Minibore

27. COLUMN DIAMETER Inlet Head Pressures Helium
I.D (mm)
Pressure (psig)
0.10
0.20
25-35
0.25
15-25
0.32
10-20
0.53
2-4
30 meters Hydrogen pressures x 1/2

28. COLUMN DIAMETER Resolution 180°C isothermal
0.53 mm
0.32 mm
Square root of resolution is inversely proportional to column diameter

29. COLUMN DIAMETER Retention 80°C isothermal
21.81
0.25 mm 5 10 15 20
16.06
0.32 mm 2 4 6 8 10 12 14 16
Isothermal: Retention is inversely proportional to column diameter Temperature program: 1/3-1/2 of isothermal values

30. COLUMN DIAMETER Capacity Like Polarity Phase/Solute
I.D. (mm)
Capacity (ng)
0.20
50-100
0.25
75-150
0.32
0.53
0.25 um film thickness

31. COLUMN DIAMETER Carrier Gas Flow Rate
Smaller diameters for low flow situations (e.g., GC/MS)
Larger diameters for high flow situations (e.g., purge & trap, headspace)

32. COLUMN LENGTH
Most common: meters
Available: meters

33. COLUMN LENGTH Resolution and Retention 210°C isothermal
2.29 min
R=1.16
4.82 min
R=1.68
8.73 min
15 m
30 m
60 m
Square root of resolution is inversely proportional to length Isothermal: Retention is proportional to length Temperature program: 1/3-1/2 of isothermal values

34. COLUMN LENGTH Inlet Head Pressures Helium
Length (m)
Pressure (psig) 15
8-12 30
15-25 60
30-45
0.25 mm I.D. Hydrogen pressures x 1/2

35. FILM THICKNESS
Most common: um
Available: um

36. FILM THICKNESS Retention 100°C Isothermal2 4 6 8
7.00
0.25 um 5 10 15 20 25
24.59
1.00 um
Isothermal: Retention is proportional to film thickness Temperature program: 1/3-1/2 of isothermal values

37. FILM THICKNESS Equal Retention: Isothermal2 4 6 8
7.00
0.25 um
100°C
1.00 um 2 4 6 8
7.08
137°C
DB-1, 30 m x 0.32 mm ID He at 37 cm/sec C10, C11, C12

38. FILM THICKNESS Resolutiond f
When solute k > 5
When solute k < 5

39. FILM THICKNESS Resolution at Low k
1.2
1.4
1.6
1.8 2 3 4 6
0.25 um
1.00 um
3.00 um
2.0 min
3.5 min
6.5 min
DB-1, 30 m x 0.32 mm ID 40°C isothermal, He at 35 cm/sec Solvent mixture

40. FILM THICKNESS Resolution at High k
R = 0 k = 0.09
1.900
2.000
2.100
2.200
3.6
3.8
4.0
4.2
4.4
4.6
4.8
5.0
R = 0.81 k = 2.55
R = k = 13.46
5.00 um 10 12 14 16 18
0.25 um
1.00 um
2.2 min
5.0 min
18.0 min
DB-1, 30 m x 0.32 mm ID 40°C isothermal, He at 35 cm/sec Solvent mixture

41. FILM THICKNESS Capacity Like Polarity Phase/Solute
Thickness (um)
Capacity (ng)
0.10
50-100
0.25
1.0
3.0
5.0
0.32 mm I.D.

42. FILM THICKNESS Bleed
More stationary phase = More degradation products

43. FILM THICKNESS Inertness Summary
0.25
1.0
3.0
active
inactive
active
inactive
active
inactive

44. COLUMN DIMENSIONS Diameter Summary
To Increase
Make Diameter
Resolution
Smaller
Retention
Pressure
Flow rate
Larger
Capacity

45. COLUMN DIMENSIONS Length Summary
To Increase
Make Length
Resolution
Longer
Retention
Pressure
Cost

46. COLUMN DIMENSION Film Thickness Summary
To Increase
Make Film
Retention
Thicker
Resolution (k<5)
Resolution (k>5)
Thinner
Capacity
Bleed
Inertness