Choosing the Best Column for Your Analysis

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Typical Gas Chromatographic System

The optimal column will give the greatest resolution in the shortest analysis time.

Column

Flow Controller

Regulators

Air

Hydr

ogen

Carri

er G

as

Mol-Sieve Traps

Fixed

Injection Port Detector Electrometer

Recorder/ Integrator

Restrictors

Cylinders or Generators

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Stationary Phase Polymers

H H

HO - - C-C-O - - H

H H n Polyethylene glycol backbone

Siarylene backbone

Siloxane

R = methyl, phenyl, cyanopropyl, trifluoropropyl

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Capillary Column Types

Liquid Phase

Carrier Gas

Porous Layer Open Tube (PLOT)

Wall Coated Open Tube (WCOT)

Solid Particles

Carrier Gas

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Agilent J&W has over 50 different stationary phase offerings

WCOT Column Types

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FactorFourTM Phases

VF-1ms, VF-5ms, VF-5ht, VF-5ht UltiMetal™

VF-17ms, VF-17ms for PAH, VF-35ms,

VF-200ms,VF-Xms, VF-23ms, VF-624ms,

VF-DA, VF-1301ms, VF-Pesticides,

VF-1701ms, VF-WAXms

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“Specialty phases” are columns that are optimized to perform a specialized GC analysis.

Column Typical Application DB-624 EPA and USP volatiles DB-VRX volatiles analysis HP-VOC volatiles analysis DB-502.2 EPA Method 502.2 DB-5.625 EPA semi-volatiles analysis DB-608 EPA Method 608 DB-1701P EPA pesticides analysis DB-MTBE total petroleum hydrocarbon (TPH) HP-PONA petroleum hydrocarbon analysis DB-HT SimDis hi-temp simulated distillation DB-ALC1 & ALC2 blood alcohol analysis HP-88 fatty acid methyl ester (FAME)

20+ Different “Specialty Phases”

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Select TM Column Examples

Environmental applications

CP-Sil 88 for dioxins, Select mineral oil, CP-Select 624 CB

Chiral applications

CP-Chirasil Val, CP-Chirasil-DEX CB

Chemical applications

CP-Volamine, CP-Select CB for MTBE, CP-PONA C8, CP-Propox,

Select Silanes, CP-SimDist UltiMetal TM , CP-Lowox TM

Food and Beverage applications

CP-Carbowax 400, Select FAME, CP-Sil 88 for FAME, CP-FFAP

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PLOT columns are primarily, but not exclusively, used for the analysis of gases and low boiling point solutes (i.e., boiling point of solute is at or below room temperature).

PLOT Column Types • Agilent J&W PLOT columns begin

with the designation of

– GS (Gas Solid) or

– HP-PLOT followed by a specific name

– 10 stationary phases • GS-OxyPLOT

• GS-Alumina

• HP-PLOT Al2O3 “M”

• HP-PLOT Al2O3 “S”

• HP-PLOT Al2O3 “KCl”

• HP-PLOT MoleSieve

• GS-CarbonPLOT

• HP-PLOT Q

• HP-PLOT U

• GS-GasPro

• GS-OxyPLOT: oxygenates • HP-PLOT Molesieve: O2, N2, CO, Methane • HP-PLOT Alumina and GS-Alumina: complex hydrocarbon gas matrices, ethylene and

propylene purity, 1,4-butadiene • HP-PLOT Q: freons, sulfides • HP-PLOT U: C1 to C7 hydrocarbons, CO2, Polar Hydrocarbons • GS-GasPro: freons, sulfurs, inorganic gases • GS-CarbonPLOT: inorganic and organic gases

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PLOT GC Columns from Varian Line Porous Polymers

• CP-PoraBOND Q

• CP-PoraBOND U

• CP-PoraPLOT Q

• CP-PoraPLOT U

• CP-PoraPLOT S

• CP-PoraPLOT Q-HT

• CP-PoraPLOT amines

Zeolites • Molsieve 5A

• Molsieve 13x

Alumina

• KCL

• Na2SO4

• MAPD Multi Layer • CP-Lowox Porous Silica • SilicaPLOT Graphatised Carbon • CP-CarboPLOT P7 • CP-CarboBOND SelectTM permanent gases

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Particle and Bonded PLOT columns ‘In-situ’ polymerization process •High mechanical stability

– No particle loss •Increased max. temp. specification

– Larger app. range – Fast bake-out

• CP-PoraBOND Q • CP-PoraBOND U • CP-CarboBOND

5 to 50 um

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Plot Column Utility

• Permanent gases Noble gases, O2, N2, H2, CO, CO2, CH4

• Light hydrocarbons C1 – C8, saturated, unsaturated, aromatics natural gas, C2,C3,C4

streams • Volatile sulfur compound

H2S, COS, mercaptanes, sulfides, disulfides • Oxygenates Alcohols, ketones, ethers • Solvents Oxygenates, aromatics, alkanes, chlorinated hydrocarbons. Chlorinated and fluorinated hydrocarbons

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Packed Columns

Packed Column Designs and Materials

1950 Introduction with the first gas chromatographs

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Properties of Chromosorb Support Materials

Chromosorb P for high load: volatiles, light hydrocarbons Chromosorb WHP, T, 750 for max inertness: acids, basics

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Packed Column Comparison with Mega-bore Fused Silica

• Robust, virtually unbreakable & bendable – Ideal in complex analyzer constructions with limited spacing

•Very high sample load possible, 2 – 5mL – Trace analyses for ppm gas impurities

• Simple sample introduction, direct injection, on-column – Syringe or gas sampling valve – Micro-packed columns (0.8mm ID) with “high” efficiency

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Packed Column Anatomy

Packed Columns • 1 – 12 m length • Internal Diameter 0.5 – 4mm • Tubing

– Stainless Steel, UltimetalTM SS, Glass, Nickel, Teflon • Packing

– Coated packing • Inert, solid support (diatomaceous earth) coated with liquid stationary

phase (e.g. OV-1, SE-30, Carbowax 20M, FFAP) – Porous packing

• Porous polymers (PoraPak Q, N, HayeSep Q, R, S, etc.) • Porous carbons (Carboxens, Carbosieves, Carbotraps)

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Packed Column Utility

Petrochemical & Chemical, main market – Process analyzers – Lab based analyzers

• Gas analyzers, CO, CO2, PIONA, Refinery gas – ASTM, IP, ISO and UOP methods

• E.g.TCEP, DC-200, SE-30, OV-1 – Gas analyses

• HayeSeps, Carboxens – Micro-GC

• Micro-packed columns for Natural Gas modules – Simple chemical purity analyses

• Older methods

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Selectivity Relative spacing of the chromatographic peaks The result of all non-polar, polarizable and polar interactions that cause a stationary phase to be more or less retentive to one analyte than another

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Impact of Efficiency, Selectivity and Retention on Resolution

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Res

olut

ion

Increase N Increase Alpha Increase k'

R s = N ½ /4 • ( α - 1)/ α • k ’ /(k ’ +1)

Plates: 5000 10000 15000 20000 25000 Alpha: 1.10 1.35 1.60 1.85 2.1 k ’ : 2.0 4.5 7.0 9.5 12.0

Plates: 5000 10000 15000 20000 25000 Alpha: 1.10 1.35 1.60 1.85 2.1 k ’ : 2.0 4.5 7.0 9.5 12.0

Typical Method Development Parameters

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Optimizing Selectivity

Match analyte polarity to stationary phase polarity

Like dissolves like (oil and water don’t mix)

Take advantage of unique interactions between analyte and stationary phase functional groups

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Final chromatograms for both the primary and confirmation columns for optimized CLP pesticides analysis.

2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00

DB-XLB

2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00

DB-17ms

22 21

20

19

18

17

16 15 14

13 12

11 10

9 8 7

6

5

4

3

2

1

22

21

20

19

18 17 16

15 14

13 12

11

10 9 8 7

6

5

4

3 2

1

CLP Pesticides with High Efficiency Columns

5989-7616EN

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PCB Congener Analysis • PCBs – PolyChlorinated Biphenyls, a mixture of up to 209 congeners • DB-XLB has been shown to provide excellent selectivity for this application. • Refer to pages 369-371 of Agilent Consumables Catalog for a list of

chromatograms and conditions for PCB applications.

min6 8 10 12 14 16 18

Hz

150

200

250

300

350

ECD1 A, ECD1A, Front Signal (CHUANHONG FISH OIL DATA JAN 2007\20070122-PCB\PCB02-CALIBRATION IN ISO-OCTANE 2007-01-22

min 4 6 8 10 12 14 16 18

Hz

500

1000

1500

2000

2500

3000

3500

4000

28 52 101 118 153 138 180 Heart Cuts

Column 2: DB-200 P/N 122-2033

30m x 0.25mm x 0.5 μm

Column 1: DB-XLB P/N 121-1232

30m x0.18mm x 01.8μm

52 101

118

153

138

180

28

Heart Cutting with the Deans Switch to Isolate Target PCBs from Fish Oil Spiked with Aroclor 1260

5989-6095EN

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Selectivity is important but not everything…

High inertness and low bleed can be critical factors in column selection. Temperature limits will play a role as well. These parameters are analyte defined.

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Stationary Phase Bleed

A thermodynamic equilibrium process that occurs to some degree in all columns, and is proportional to the mass amount of stationary phase inside the capillary tubing/carrier gas flow path

Polysiloxane backbone releases low molecular weight, cyclic fragments

Is negligible in low temperature, O2-free, clean GC systems

Increased by increased temperature, oxygen exposure, or chemical damage

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Bleed: Why Does It Happen? “Back Biting” Mechanism of Product Formation

+

Repeat

Si Si Si Si Si Si Si O O O O O O OH CH3 CH3 CH3 CH3 CH3 CH3 CH3

CH3 CH3 CH3 CH3 CH3 CH3 CH3

OH Si Si O Si O Si O CH3 CH3 CH3 CH3

CH3 CH3 CH3 CH3

Si O O

O

CH3 H3C

H3C H3C

Si Si CH3

CH3

O O O O O

O Si

HO

H3C

CH3 CH3 CH3 CH3 Si Si Si Si Si Si CH3

CH3

CH3

CH3 CH3 CH3 CH3

CH3 CH3

Cyclic products are thermodynamically

more stable!

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DB-5ms Structure

CH 3 CH 3

CH 3 CH 3

CH 3 CH 3

Si

Si

Si

Si

O

O

O

O DB-5 Structure

DB-5 5% Phenyl

CH 3

CH 3

CH 3

CH 3 CH 3

CH 3 CH 3

CH 3

Si

Si

Si

Si O

O

DB-5ms Structure

DB-5ms 1.Increased stability 2.Different selectivity 3.Optimized to match DB-5

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Solid line: DB-5ms 30 m x .25 mm I.D. x .25 µm Dashed line:DB-5 30 m x .25 mm I.D. x .25 µm Oven: 60o C isothermal Carrier gas: H2 at 40 cm/sec 1: Ethylbenzene 2: m-Xylene 3: p-Xylene 4: o-Xylene

Difference in Selectivity

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Four Types Of Low Bleed Phases

Phases tailored to “mimic” currently existing polymers -Examples: DB-5ms, DB-35ms, DB-17ms, DB-225ms

Phases unrelated to any previously existing polymers

-Examples: DB-XLB Optimized manufacturing processes

-DB-1ms, HP-1ms, HP-5ms

Hand selected columns

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Benefits of Low Bleed Phases PAH Sensitivity Using DB-35MS

1. Naphthalene 2. Acenaphthylene 3. Acenaphthene 4. Fluorene 5. Phenanthrene 6. Anthracene 7. Fluoranthene 8. Pyrene 9. Benz[a]anthracene 10. Chrysene 11. Benzo[b]fluoranthene 12. Benzo[k]fluoranthene 13. Benzo[a]pyrene 14. Indeno[1,2,3,-c,d]anthracene 15. Dibenz[a,h]anthracene 16. Benzo[g,h,i]perylene

Columns: 30 m x 0.32 mm x 0.35 um. Carrier: H2, constant flow, 5 psi at 100 oC. Injector: 275 oC, splitless, 1 ul , 0.5-5ppm. Oven: 100 oC to 250 oC (5 min.) at 15 oC/min.,; then to 320 oC (10 min.) at 7.5 oC/min. Detector: FID, 320 oC.

5 10 15 20 25 min.

DB-35MS

1

2

3

4

5 6

7

8

9 10

11 12 13 14

15 16

Commercially Available 35% phenyl column

Benzo[ghi]perylene S/N = 120

Benzo[ghi]perylene S/N = 15

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Polarity vs Stability/Temperature Range

Polarity Stability Temperature Range

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Stationary Phase Selection Existing information

Selectivity/Polarity

Critical separations

Temperature limits

Application designed Examples: DB-VRX, DB-MTBE, DB-TPH, DB-ALC1, DB-ALC2, DB-HTSimDis, DB-Dioxin, HP-VOC, and now SelectTM phases Choose the column phase that gives the best separation but not at the cost

of robustness or ruggedness.

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Column Diameter - Theoretical Efficiency I.D. (mm)

0.05

0.10

0.20

0.25

0.32

0.45

0.53

0.18

n/m

23,160

11,580

5830

4630

3660

2840

2060

6,660

30 m

20 m

10 m

k = 5

5 m

N ~ 112,000

N ~ 112,000

N ~ 112,000

N ~ 112,000

Total Plates

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PHASE RATIO (β) Film Thickness

Column Dimensions Phase Ratio β 30 m x .53 mm x 3.0 µm 44 30 m x .32 mm x 1.8 µm 44

KC = k β

r 2df

β =

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Different Column I. D. Equal Phase Ratios

Time (min) 0 5 10 15 20

Carrier: Oven: 65° C Injection: Split Detector: FID

Column : DB-624 30 m, 0.32 mm, 1.8 m

Helium, 40 (cm/sec)

Column : DB-624 30 m, 0.53 mm, 3 m

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Column Diameter and Capacity

Like Polarity Phase/Solute 0.25 µm film thickness

I.D. (mm) Capacity (ng)

0.05 1-2

0.18 25-55

0.20 35-70

0.25 80-160

0.32 110-220

0.53 1000-2000

0.45 600-800

0.10 6-13

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Column Diameter - Inlet Head Pressures (Helium)

30 meters Hydrogen pressures x 1/2

I.D (mm) Pressure (psig)

0.10 90-130

0.20 25-40

0.25 15-25

0.32 10-20

0.45 3-7

0.53 2-4

0.18 30-45

0.05 275-400

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Column Diameter and Carrier Gas Flow

Lower flow rates: Smaller diameter columns

Higher flow rates: Larger diameter columns

Low flow rates : GC/MS High flow rates: Headspace, purge & trap

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Diameter Summary

If you decrease the inside diameter:

Efficiency Increase

Resolution Increase

Pressure Increase

Capacity Decrease

Flow rate Decrease

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Film Thickness and Capacity

0.32 mm I.D. Like Polarity Phase/Solute

Thickness (µm) Capacity (ng)

0.10 50-100

0.25 125-250

0.50 250-300

1 500-1000

3 1500-3000

5 2500-5000

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Film Thickness and Bleed

More stationary phase = More degradation products

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Film Thickness and Inertness 1.0

active inactive active inactive

3.0

active inactive

0.25

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Film Thickness Summary

If you increase the film thickness: Retention Increase Resolution (k<5) Increase Resolution (k>5) Decrease Capacity Increase Bleed Increase Inertness Increase Efficiency Decrease

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Column Length and Resolution

Page 43

Length X 4 = Resolution X 2

R α √ n α √ L

t α L

15 m 60 m 30 m

R=0.84 2.29 min

R=1.68 8.73 min

R=1.16 4.82 min

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Analysis of Naphtha • Shorter column, Smaller column diameter same phase ratio

Same β

CP-Sil 5 PONA250 µm x 100 m Df = 0.5µm, ß = 4500P = 45 PSI (315 kPa)

CP-Sil 5 PONA100 µm x 40 m Df= 0.2µm, ß = 500P = 95 PSI (670 kPa)

20 min

80 min

Naphtha

Similar separation3 to 4 time faster

125

125

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Length Summary

If you Increase Length:

Efficiency Increase

Resolution Increase

Analysis Time Increase

Pressure Increase

Cost Increase

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Level of Inertness

•Important for active analytes

•Semi-volatiles

•Acidic compounds

•Basic compounds

•Unknowns that may contain active analytes

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High Temperature GC Analysis

• Hydrocarbons • Paraffin or hydrocarbon waxes

– Polywax 655, 1000, 2000 • Heavy vacuum residues • Crudes, SimDist • Natural waxes • Carnauba wax, Bees wax • Triglycerides • Biodiesel, vegetable oils • Polymer Additives • Surfactants

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Critical Parameters in HT GC

• Oven

• Detection • HT FID, MS • Injection • Critical sample introduction • Reduce discrimination effects • On-column techniques • Column • Tubing material: fused silica/metal • Liquid phase temperature robustness

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UltiMetal™ surface coating and GC Columns

SS tubing

1st layer:: SS surface treatment

2nd layer: Deactivation layer

3rd layer: Liquid phase layer

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UltiMetal™, SiO2 Deposition Technology Applied for Packed Columns and 0.53mm Capillary Columns

316 SS tubing

1st layer: SS surface treatment

2nd layer: Deactivation layer

Coated packing

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UltiMetal™ surface coating

Inert coating surface Virtually unbreakable Flexible SS tubing Coating of all liquid phases Phase stabilization Low column bleed Coupling issues

SiO2 Deposition Techniques

Inert coating surface

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Improved Efficiency and Peakshape

1m x 1/8” packed column, 5% OV-101 on Chromosorb WAW, 80 - mesh Analysis at 120°C

N-C11

N-C12

n-C13

n-C14

UltiMetal™ Regular SS

+50%

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SimDist Analysis C20 – C100

430°C

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Phase Degradation on Different Column Surfaces

Column Bleed Characteristics at High Temperature

0

5

10

15

20

25

30

35

40

250 Oven Temperature (°C)

Mea

sure

d B

leed

(pA

)

275 300 325 350 375 400 425 450 475

Up to 325 ºC virtually NO bleeding

Non-polar phase on UltiMetal™ PDMS deactivated surface: VF-5ht

Non-polar phase on fused silica PDMS deactivated surface: VF-5ms

x x x x x

UltiMetal™ seems superior for HT applications

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HT Analysis of Palm Oil Column: VF-5HT UltiMetal™ , 30m x 0.25mm x 0.1µm

400°C

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Polymer Additives

min5 10 15 20 25 30 35

pA

50

100

150

200

250

300

350

400

FID1 A, (JAN\JN17EB06.D)

1 2 3

4

5 9

10

solv

ent

GC-settings: Mode= constant flow Gas type= Nitrogen Pressure= 4.00 psi Flow= 0.5 ml/min. Average velocity= 16 cm/sec Injection volume= 0.5 µl Inlet= cool on-column Detector temp.= 400°C

Oven program: Oven ramp °C/min next °C Hold min. Initial 40 2.00 Ramp 1 40 180 0.00 Ramp 2 10 400 12.50 Run time = 40.00 min.

Column: WCOT Ulti-Metal VF-5ht-SimDist (Cat. no. CP9091) 15m x 0.25mm x 0.10µm (df) + 2m RG

VF-5HT 15m x 0.25mm x 0.1μm

PETS release agents

1. AO2246 2. Tinivin 350 3. Cyasorb 5411 4. Irgafos 16 5. Tinuvin 234 9. Oxidized Irgafos 168

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HT-GC-FID Polymer Additives

Narrow Bore Advantages

Varian Ultimetal, VF-5HT 15m x 0.25mm x 0.1μm + 2m 0.53mm Ultimetal RG

Varian Ultimetal, SimDist, 100% PDMS 10m x 0.53mm x 0.07μm

400°C

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Column Coupling

Factory installed guard columns & retention gaps for 0.53mm, 0.32mm & 0.25mm UltiMetal™ columns

Ready for use Leak tested Perfect Chromatography Extended column lifetimes

Poor & Good Coupling 0.53mm RG 0.25mm / 0.32mm column

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UltiMetal™ column Summary • 3 phases for high temperature GC

– SimDist – Select for Biodiesel – VF-5ms

• All Internal diameters – 0.25mm – 0.32mm – 0.53mm

• Factory installed 0.53mm UltiMetal™ retention gaps

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Easy ordering Agilent packed columns

Packed Columns Quotation Request Form

Infinite number of combinations: • Supports • Liquid phases • Tubing material • Tube dimensions • Type GC (glass columns)

Packed Columns Quotation Request Form simplifies quotation process

UltiMetal option

Further Options: • Preconditioning and testing • Bending • Nuts & ferrules choice

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Column Selection Summary Stationary Phase Type – consider polarity and column type

Column Internal Diameter- consider speed, inj. volume & cost Stationary Phase Film Thickness- consider retention, capacity

and potential for bleed

Column Length- consider shortest column for analysis

Level of inertness- consider sample activity

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Power of Two From Agilent J&W The innovation, quality and products you have come to know including

our newest offerings Ultra Inert Column line High efficiency GC column line

From our New Colleagues The innovation, quality and products you have come to know including

some new offerings CP PoraPLOT and CP CarboPLOT columns SelectTM Series UltiMetalTM High temperature columns

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Thank you. Questions?

GC Method Translation,

There’s an App for That.

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Addendum - Optimizing Selectivity

Match analyte polarity to stationary phase polarity

Like dissolves like (oil and water don’t mix)

Take advantage of unique interactions between analyte and stationary phase functional groups

Mexico 2012