Gas chromatography & cc ms principles is2008-04-18

GC Basic Principles

What is chromatography

• Separation Science

• Organizing by size

• Organizing by boiling point

(vapor pressure)

• Organizing by solubility

Before

After

• Performed in the vapor state

• Requires a mobile phase, gas

• Requires a stationary phase

• Molecules migrate between the phases

What is Gas Chromatography

GC Instrument

Gas Chromatographic Equipment

INTEGRATORSAUTOSAMPLERS GC BASIC UNITS GC DETECTORS

MS DETECTORS

MS Detector

AutosamplerGC

Detector

Autosampler

Data

system

GC Basic

Unit

Gaschromatog.DATA SYSTEMS

SAMPLEPREPARATIONSYSTEMS

GC Basic

UnitData

system

SAMPLEPREPARATION

AND INJECTIONSYSTEMS

CHROMATOGRAPHICSEPARATION

SYSTEMS

DETECTION &IDENTIFICATION

SYSTEMS

DATASYSTEMS

GC/SA Benchtop GC/MS

GC Instrument : injector

Requirements for the ideal injector

• Capable to quantitative accept a broad volatility range of sample

components

– Low discrimination

• To handle dirty and clean matrices

– With dirty matrices reduces sample clean-up

– With clean matrices boosts sensitivity

• Extremely inert

– Able to handle polar/active compounds

• Provide optimum band shape

Vaporizing

Injectors:SSL

PPKD

PKD

PTV

No-vaporizing

Injectors:

On-column

Injection techniques

Injectors

True cold on-column

split/

splitless

PTV Packed and

wide-bore

columns

General criteria for injection system selection

PTV PTV

PRIMARY COOLING

SYSTEM

SECONDARY COOLING

SYSTEM

Room

temperature Temp.

SBP

Liquid sample

droplets

Liquid sample

plug Liquid sample

film

1 2

Carrier

gas

Cooling fluid

(secondary

cooling)

Primary

cooling

system

Oven

temperature

3

Cold On-Column Injector

Split Injector

Carrier

Septum Purge

Split Line

Glass Liner5 mm ID

Length of Column Inside Injector = 40 mm

CapillaryColumn

7001-1417970810

Additional Insulating

50 mm

Syringe

Splitting Point

Liner

Carrier Pathway

ColumnTerminalFitting

InjectorChamber

Splitless Injector

Carrier

Septum Purge

Split Line

80 mm

Syringe

Length of Column Inside Injector = 64 mm

CapillaryColumn

77001-1416970805

Additional Insulating

SplitlessLiner

PTV Injector

Septum

purge

line

Splitting

line

Carrier

OVEN

Column

Liner

Carrier gas

inlet

SeptumSeptum purge line

Splitting

line

FORCED AIR

COOLING

Heating

element

GC Instrument

GC Instrument : column oven

Automatic Column Characterisation

Automatic Column Characterisation

Injector Pressure Programming

GC Instrument

Detectors Overview

Detectors Principles

RESPONSE TYPE

RESPONSE MECHANISM

DESTRUCTIVENON DESTRUCTIVE

• Concentration dependent: TCD, ECD, PID

• Mass rate dependent: FID, NPD, FPD

• Universal: TCD, FID, (PID)

• Selective: ECD, NPD, FPD, (PID)

• FID, NPD, FPD• TCD, ECD, PID

Detectors Characteristics

Air

Column effluent

+Hydrogen

FID : Flame Ionization Detector

Column effluent + make-up gas

Radioactive source

Outlet

ECD : Electron Capture Detector

Air

Column effluent + Hydrogen

Heated source

Collectingelectrode

NPD : Nitrogen Phosphorous Detector

Photomultipier tube

Interferencefilter

Air

Column effluent+ Hydrogen

FPD : Flame Photometric Detector

Quartz cell

GC column Exit tube

Heat sink

UV lamp

PID : Photo Ionization Detector

Application Note: Blood/Alcohol

Coupling Chromatography to

Mass Spectrometry

Separation plus identification

Source & Analyzer

TRACE DSQ components

Ion Source

Curved Quadrupole Pre-filter

Analytical

Quadrupole

Detector

Quadrupole Wiring

• Y Quadrupole Rod Pair

• AC and neg DC Voltage0

0.5

1

1.5

2

2.5

0 0.5 1 1.5 2

Series1

• X Quadrupole Rod Pair

• AC and pos DC Voltage

Stability Regions

APEX (0.706, 0.23699)

XZ-stable

YZ-stable

Mathieu Parameters

RF = m r2 2

e 2qz

DC = m r2 2

e 4az

e = charge (constant =1)

m = Mass in kg

r = radius = distance between rod inner surface and center of quadrupole

w = 2 * frequency (1100 kHz)

DSQ II Single Quadrupole

Literature Available for DSQ II

• Confirmation of Drugs of Abuse Application/Technical Notes

Marijuana Cocaine

PCP Amphetamines Opiates