Multi-Dimensional Gas Chromatography Multi-Dimensional Gas Chromatography State-of-the-ArtState-of-the-Art

J.-M. D. DimandjaJ.-M. D. Dimandja

January 16, 2007January 16, 2007

Chromatography in ContextChromatography in Context

SelectiveSelective ComprehensiveComprehensive

1D GC1D GC Sample Sample Preparation Preparation CartridgesCartridges

Conventional Conventional 1D GC1D GC

2D GC2D GC Heartcut Heartcut

GC-GCGC-GC

GCxGCGCxGC

GCxGC InstrumentationGCxGC Instrumentation

Data Processor

Detector

Modulator

Injector

PrimaryColumn

SecondaryColumn

What is Modulation?What is Modulation?

AudioSignal

AMFM

Modulator Demodulator

Transmission DesiredAudio Signal

1st DimensionGC Signal

Modulator Demodulator

TransmissionThrough 2nd

GC Dimension

DesiredMulti-dimensional

Signal

Role of the GCxGC ModulatorRole of the GCxGC Modulator

Amplitude ModulationAmplitude ModulationFrequency ModulationFrequency ModulationPhase ModulationPhase Modulation

The modulator plays a key role in the The modulator plays a key role in the optimization of a GCxGC methodoptimization of a GCxGC method

Types of GCxGC ModulatorsTypes of GCxGC Modulators

Thermal ModulatorsThermal ModulatorsValve ModulatorsValve Modulators

Will be covered by Prof. SeeleyWill be covered by Prof. Seeley

Modulator Figures-of-MeritModulator Figures-of-Merit

Sampling efficiencySampling efficiencyTemperature operating rangeTemperature operating rangeTechnical sophisticationTechnical sophisticationRuggednessRuggednessCostCost

Evolution of Thermal ModulatorsEvolution of Thermal Modulators

ResistorsResistorsThermal scannersThermal scannersThermal jets Thermal jets

Thermal Resistor PrincipleThermal Resistor Principle

Resistive heatingResistive heatingRapid cooling due to low thermal mass of Rapid cooling due to low thermal mass of

the resistive film the resistive film

Rearview DefoggerRearview Defogger

Defogger OperationDefogger Operation

Resistive paint Resistive paint heatedheated

Defogging occursDefogging occurs

Napa Defogger kitNapa Defogger kit

The Original Resistor The Original Resistor (Liu/Phillips, 1988)(Liu/Phillips, 1988)

Stationary Phase

Electrically Conductive Paint

Resistor Pros/ConsResistor Pros/ConsPoorPoor GoodGood ExcellentExcellent

Sampling EfficiencySampling Efficiency XX

Temperature RangeTemperature Range XX

Technical Technical SophisticationSophistication

XX

RuggednessRuggedness XX

CostCost XX

ImprovementsImprovements

Two-stage modulation (Liu, 1989)Two-stage modulation (Liu, 1989)Thicker stationary phase (Liu, 1990)Thicker stationary phase (Liu, 1990)Dry-ice resistor (Venkatramani, 1991)Dry-ice resistor (Venkatramani, 1991)Stainless-steel, multi-stage resistor Stainless-steel, multi-stage resistor

(Burger, 2003)(Burger, 2003)

Resistor SummaryResistor Summary

Interfaced with HRMS (1994) and TOF MS Interfaced with HRMS (1994) and TOF MS (1996)(1996)

Academia (prototype development), Academia (prototype development), Industry (Shell), government R&D (CDC)Industry (Shell), government R&D (CDC)

Cheap and easy to assemble, but not Cheap and easy to assemble, but not commercially viablecommercially viable

Thermal Scanning PrincipleThermal Scanning Principle

Mechanically activated modulator that scans a given section of the columnto produce the modulation.

1

2

Dual-Oven Heat Shuttle (Xu, 1993)Dual-Oven Heat Shuttle (Xu, 1993)

12

Single-Oven Heat Shuttle Single-Oven Heat Shuttle (Xu, 1994)(Xu, 1994)

12

Inside-Oven Cryo-Shuttle Inside-Oven Cryo-Shuttle (Marriott, 1995)(Marriott, 1995)

12

Inside-Oven Heat Shuttle -- Inside-Oven Heat Shuttle -- Thermal Sweeper Thermal Sweeper

(Ledford/Phillips, 1997)(Ledford/Phillips, 1997)

12

Thermal Scanner Pros/ConsThermal Scanner Pros/ConsPoorPoor GoodGood ExcellentExcellent

Sampling EfficiencySampling Efficiency XX

Temperature RangeTemperature Range XX

Technical Technical SophisticationSophistication

XX

RuggednessRuggedness XX

CostCost XX

Thermal Scanner SummaryThermal Scanner Summary

First “commercial” system (Sweeper, First “commercial” system (Sweeper, 1997)1997)

Petroleum industry, government R&D Petroleum industry, government R&D (CDC, CGA)(CDC, CGA)

Data processing issues (no software for Data processing issues (no software for automated visualization and/or automated visualization and/or quantitation)quantitation)

Jet Modulator PrincipleJet Modulator Principle

Active cooling and heating stagesActive cooling and heating stagesThermal scanners only have one active Thermal scanners only have one active

stage (either heating or cooling, but not stage (either heating or cooling, but not both)both)

Single-Stage, Dual-Jet Single-Stage, Dual-Jet (Beens, 2001)(Beens, 2001)

Trapping phase

Single-Stage, Dual-JetSingle-Stage, Dual-Jet

Release phase

Two-Stage, Quad-Jet Modulation Two-Stage, Quad-Jet Modulation (Ledford, 2001)(Ledford, 2001)

TRAP

Two-Stage, Quad-Jet ModulationTwo-Stage, Quad-Jet Modulation

FOCUS

Two-Stage, Quad-Jet ModulationTwo-Stage, Quad-Jet Modulation

RELEASE

Two-Stage, Dual-Jet Modulation Two-Stage, Dual-Jet Modulation (Ledford, 2002)(Ledford, 2002)

Two-Stage, Dual-Jet ModulationTwo-Stage, Dual-Jet Modulation

Two-Stage, Dual-Jet ModulationTwo-Stage, Dual-Jet Modulation

Two-Stage, Dual-Jet ModulationTwo-Stage, Dual-Jet Modulation

Thermal Jets Pros/ConsThermal Jets Pros/ConsPoorPoor GoodGood ExcellentExcellent

Sampling EfficiencySampling Efficiency XX

Temperature RangeTemperature Range XX

Technical Technical SophisticationSophistication

XX

RuggednessRuggedness XX

CostCost XX

Thermal Jet SummaryThermal Jet Summary

Curent commercially available state-of-Curent commercially available state-of-the-art in GCxGCthe-art in GCxGC

Industry, academia, governmentIndustry, academia, governmentAchilles heel: consumablesAchilles heel: consumables

Gaines/Frysinger solutionGaines/Frysinger solutionHarynuk/Gorecki solutionHarynuk/Gorecki solution

ConclusionsConclusions

InstrumentInstrument

DevelopmentDevelopment

ModulationModulation

ApplicationApplication

DevelopmentDevelopment

DemodulationDemodulation

(Data Processing (Data Processing Software)Software)