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

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

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

POLYSILOXANES Phenyl methyl Substituted 3 CH m n Si O 5% phenyl (DB-5) 35% phenyl (DB-35) 50% phenyl (DB-17)

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

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

POLYSILOXANES Cyanopropylphenyl methyl Substituted 3 H 6 CN n m Si O 6% cyanopropylphenyl (DB-1301) 14% cyanopropylphenyl (DB-1701) 50% cyanopropylphenyl (DB-225)

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

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

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

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

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

POLARITY Solubility And Retention 2 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 50-170°C at 15°/min

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

DISPERSION INTERACTION Kcal/mole 2 4 6 8 10 Benzene Phenol C10 C12 8.1 11.9 10.9 DB-1 (non-polar)

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

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

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

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

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

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

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

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

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

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

COLUMN DIAMETER Capillary Columns I.D. (mm) Common Name 0.53 Megabore 0.45 High speed Megabore 0.32 Wide 0.20-0.25 Narrow 0.18 Minibore

COLUMN DIAMETER Inlet Head Pressures Helium I.D (mm) Pressure (psig) 0.10 225-250 0.20 25-35 0.25 15-25 0.32 10-20 0.53 2-4 30 meters Hydrogen pressures x 1/2

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

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

COLUMN DIAMETER Capacity Like Polarity Phase/Solute I.D. (mm) Capacity (ng) 0.20 50-100 0.25 75-150 0.32 125-250 0.53 200-400 0.25 um film thickness

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)

COLUMN LENGTH Most common: 15-60 meters Available: 5-150 meters

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

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

FILM THICKNESS Most common: 0.1-3.0 um Available: 0.1-10.0 um

FILM THICKNESS Retention 100°C Isothermal 2 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

FILM THICKNESS Equal Retention: Isothermal 2 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

FILM THICKNESS Resolution d f When solute k > 5 When solute k < 5

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

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 = 0.72 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

FILM THICKNESS Capacity Like Polarity Phase/Solute Thickness (um) Capacity (ng) 0.10 50-100 0.25 125-250 1.0 500-1000 3.0 1500-3000 5.0 2500-5000 0.32 mm I.D.

FILM THICKNESS Bleed More stationary phase = More degradation products

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

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

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

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