This document provides information about gas chromatography. It defines chromatography and gas chromatography, describes the basic components of a gas chromatography instrument including the carrier gas, injector, column, oven, and common detectors. It explains the principles of gas chromatography and separation, and provides details about different types of columns, injection techniques, and detectors such as FID, TCD, ECD, and GC-MS.
Gas chromatography and its instrumentationArgha Sen
Gas chromatography is an unique technology which helps us in separating volatile analytes. Its is an easy and reproduciple method for detecting residual solvents found in APIs.
in this slides contains principle and types of detectors used in Gas Chromatography.
Presented by: J.Vinay Krishna. (Department of industrial pharmacy),
RIPER, anantapur.
Gas chromatography is one of the widely used chromatographic techniques, which use inert gas as the mobile phase.
In gas chromatography the components of a sample, after vaporization, are separated by being partitioned between gaseous mobile phase and solid or liquid stationary phase.
The inert gas does not interfere with the analyte but transport the components through the column and facilitate the separation.
The mobile phase is comprised of an inert gas such as helium, argon or nitrogen.
The stationary phase consists of a packed column in which the packing or solid support, or a liquid coat act as stationary phase.
The main principles involved are adsorption and partition for gas solid chromatography and gas liquid chromatography, respectively.
Gas chromatography and its instrumentationArgha Sen
Gas chromatography is an unique technology which helps us in separating volatile analytes. Its is an easy and reproduciple method for detecting residual solvents found in APIs.
in this slides contains principle and types of detectors used in Gas Chromatography.
Presented by: J.Vinay Krishna. (Department of industrial pharmacy),
RIPER, anantapur.
Gas chromatography is one of the widely used chromatographic techniques, which use inert gas as the mobile phase.
In gas chromatography the components of a sample, after vaporization, are separated by being partitioned between gaseous mobile phase and solid or liquid stationary phase.
The inert gas does not interfere with the analyte but transport the components through the column and facilitate the separation.
The mobile phase is comprised of an inert gas such as helium, argon or nitrogen.
The stationary phase consists of a packed column in which the packing or solid support, or a liquid coat act as stationary phase.
The main principles involved are adsorption and partition for gas solid chromatography and gas liquid chromatography, respectively.
Introduction to chromatography, Definition of Chromatography, Types of column chromatography, Theory of chromatography, Practical considerations in column chromatography , Factors affecting efficiency of a column, Applications.
Principle and application of ptgc and isothermal programmingAthira39
Gas chromatography is the separation of gaseous and volatile substances which is achieved by employing gas as a mobile phase and moving it through a column containing stationary phase which could be a liquid or solid.
Two methods of temperature control are used during gas chromatography:
Isothermal operation and;
Temperature programming
fluid chromatography (SFC) can be used on an analytical
scale.
It is a combination of High performance liquid chromatography (HPLC)
and Gas chromatography (GC).
It can be used with non-volatile and thermally labile analytes.
It can be used with the universal flame ionization detector.
It is important to producing narrower peaks due to rapid diffusion.
It is important for the chiral separations and analysis of high-molecularweight
hydrocarbons.
Supercritical fluids are suitable as a substitute for organic solvents in a
range of industrial and laboratory processes.
Gel chromatography, Introduction, Theory, Instrumentation, Applications .pptxVandana Devesh Sharma
Affinity chromatography- Content-Introduction
Theory
Instrumentation
Applications
Gel chromatography is a type of partition chromatography used for separating different sized molecules.
Gel chromatography is also called Gel permeation chromatography or gel filtration or gel exclusion, size exclusion, molecular- sieve chromatography.
The separation is based on the analyte molecular sizes since the gel behaves like a molecular sieve.
In size exclusion chromatography, the stationary phase is a porous matrix made up of compounds like
cross-linked polystyrene, cross-like dextrans, polyacrylamide gels, agarose gels, etc.
The gel structure being used contains pores of different diameters upto maximum size.
1.The test molecules are washed through a gel column and molecules larger than the largest pores in the gel are excluded from the gel structure.
2. Smaller molecules penetrate the gel and the extent of penetration depends on the molecular size----- This delay their movement through the column
This technique is used for the separation of proteins, polysaccharides, enzymes, and synthetic polymers. Instrumentation- A. Stationary phase- It is composed of semi-permeable, porous polymer gel beads with a well-defined range of pore sizes. eg. Dextran, Agarose, Acrylamide. 2. sample size and concentration- sample is applied in small volume (1-5% of the total bed volume).3. Column parameters- use long column, ratio of column diameter to column length (1:20 to :100). The method or steps used for gel preparation. 4. Choice of eluent/mobile phase- Buffers Ex- Phosphate buffer pH 7, NaCl solution, Ammonium acetate (CH3COO-NH4+ ), Ammonium bicarbonate (NH₄HCO₃) ethylenediamine acetate. 5. Effect of Flow rate- maintain with the help of pump. Elution carried out with buffer at optimal flow rate (Eg- 0.25-5ml/min) to give maximum resolution with optimal separation time.6. Separation of components from the sample-
Separation of component from mixture is achieved with the help of column. The retention volume (VR).7. Detection- Using UV absorption detectors. A graph of Elution Volume (ml) Vs Molecular weight. 7. Detection- Using UV absorption detectors. A graph of Elution Volume (ml) Vs Molecular weight. For calibration of the gel in column – Calibrators - (Proteins of known molecular weight. Procedure for gel filtration technique-1. Preparation of column- 2. Washing of the column- 3. Loading of the sample-4. Elution using mobile phase (buffers)5. Detection of compounds . Applications
Introduction to chromatography, Definition of Chromatography, Types of column chromatography, Theory of chromatography, Practical considerations in column chromatography , Factors affecting efficiency of a column, Applications.
Principle and application of ptgc and isothermal programmingAthira39
Gas chromatography is the separation of gaseous and volatile substances which is achieved by employing gas as a mobile phase and moving it through a column containing stationary phase which could be a liquid or solid.
Two methods of temperature control are used during gas chromatography:
Isothermal operation and;
Temperature programming
fluid chromatography (SFC) can be used on an analytical
scale.
It is a combination of High performance liquid chromatography (HPLC)
and Gas chromatography (GC).
It can be used with non-volatile and thermally labile analytes.
It can be used with the universal flame ionization detector.
It is important to producing narrower peaks due to rapid diffusion.
It is important for the chiral separations and analysis of high-molecularweight
hydrocarbons.
Supercritical fluids are suitable as a substitute for organic solvents in a
range of industrial and laboratory processes.
Gel chromatography, Introduction, Theory, Instrumentation, Applications .pptxVandana Devesh Sharma
Affinity chromatography- Content-Introduction
Theory
Instrumentation
Applications
Gel chromatography is a type of partition chromatography used for separating different sized molecules.
Gel chromatography is also called Gel permeation chromatography or gel filtration or gel exclusion, size exclusion, molecular- sieve chromatography.
The separation is based on the analyte molecular sizes since the gel behaves like a molecular sieve.
In size exclusion chromatography, the stationary phase is a porous matrix made up of compounds like
cross-linked polystyrene, cross-like dextrans, polyacrylamide gels, agarose gels, etc.
The gel structure being used contains pores of different diameters upto maximum size.
1.The test molecules are washed through a gel column and molecules larger than the largest pores in the gel are excluded from the gel structure.
2. Smaller molecules penetrate the gel and the extent of penetration depends on the molecular size----- This delay their movement through the column
This technique is used for the separation of proteins, polysaccharides, enzymes, and synthetic polymers. Instrumentation- A. Stationary phase- It is composed of semi-permeable, porous polymer gel beads with a well-defined range of pore sizes. eg. Dextran, Agarose, Acrylamide. 2. sample size and concentration- sample is applied in small volume (1-5% of the total bed volume).3. Column parameters- use long column, ratio of column diameter to column length (1:20 to :100). The method or steps used for gel preparation. 4. Choice of eluent/mobile phase- Buffers Ex- Phosphate buffer pH 7, NaCl solution, Ammonium acetate (CH3COO-NH4+ ), Ammonium bicarbonate (NH₄HCO₃) ethylenediamine acetate. 5. Effect of Flow rate- maintain with the help of pump. Elution carried out with buffer at optimal flow rate (Eg- 0.25-5ml/min) to give maximum resolution with optimal separation time.6. Separation of components from the sample-
Separation of component from mixture is achieved with the help of column. The retention volume (VR).7. Detection- Using UV absorption detectors. A graph of Elution Volume (ml) Vs Molecular weight. 7. Detection- Using UV absorption detectors. A graph of Elution Volume (ml) Vs Molecular weight. For calibration of the gel in column – Calibrators - (Proteins of known molecular weight. Procedure for gel filtration technique-1. Preparation of column- 2. Washing of the column- 3. Loading of the sample-4. Elution using mobile phase (buffers)5. Detection of compounds . Applications
Gas chromatography
1. By Pratik P. Shinde (M.Pharm )
2. Index
3. Gas chromatography- It is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. In gas chromatography, the mobile phase is a carrier gas, usually an inert gas such as helium or an unreactive gas such as nitrogen
It has two types
Gas-liquid chromatography: The mobile phase is a gas and the stationary phase is a thin layer of a non volatile liquid bound to solid support. A partition process occurs
Gas- solid chromatography: The mobile phase is a gas and the stationary phase is a solid adsorbent and adsorption process take place
4. Principle: The component which is more soluble in stationary phase travel slower and eluted later. The component which is less soluble in stationary phase travels faster and eluted out first.
Gas-liquid chromatography: The components of mixture distribute themselves between gas phase and the stationary liquid phase according to their partition coefficients.
Gas- solid chromatography: The components of mixture distribute themselves between gas phase and the stationary adsorbent and the separation is due to the differences in adsorptive behaviour.
5. Instrumentation: Carrier gas - He (common), N2, H2, Argon
Gas regulator
Sample injection port - micro syringe
Columns
Packed
Capillary
Detectors
Thermal conductivity (TCD)
Electron capture detector(ECD)
Flame Ionization detector (FID)
Flame photometric (FPD)
Recorder
6.
7. Carrier gas: Carrier gas used in gas chromatography should meet the following criteria:
The pressure of gas should be between 40-80psi.
It should be chemically inert.
It should be cheap and readily available.
It should be of high quality and not cause any fire accident.
It should be suitable for the sample to be analyzed and for the detector.
Commonly use gases include Helium, nitrogen, hydrogen and carbon dioxide.
8. Helium (He):
Good thermal conductivity
Low density
Inert but expensive
Flow rate : 25 -150 mL/min for packed columns
Flow rate: 2-25 mL/min for open tubular column
Inlet pressure ranges from 10-50psi
Nitrogen:
Inexpensive
Easily available
Hydrogen:
Low density
Easily available
React with unsaturated compound
Carbon-dioxide and Argon:
9. Gas purification and filtration: Filters and traps: Traps help remove moisture, oxygen, hydrocarbons and other impurities from gas lines. Metal or glass traps are commonly used. Plastic traps like plastic tubes are not recommended. Traps are available with standard 1/4”or 1/8” compression fittings.
Moisture traps: are generally self indicating type and packed with molecular sieves or silica gel which will reduce both oxygen and moisture to less than 15 ppb.
Hydrocarbon traps are useful for removing hydrocarbon impurities by absorption on activated charcoal. A 20 μm frit removes particulate impurities.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
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We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
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The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
3. Contents:
IUPAC Definition of Chromatography
Introduction
Definition
Types of GC
Principle
Instrumentation
Working animation
Troubleshoots
Applications
3
4. IUPAC Definition of Chromatography :
“A physical method of separating sample components from a mixture by
selective adsorption or partitioning of the analyte between two phases:
a mobile phase and a stationary phase”.
Stationary Phases
1. Solids (alumina, silica, polymers,
carbon…)
• Adsorption chromatography
2. Liquids (siloxanes, polyethylene
glycols…)
• Partition chromatography
Mobile Phases
1. Liquids (methanol, water…)
•Changing dielectric strength,
temperature, pH
2. Gases (nitrogen, helium, hydrogen,
argon)
4
5. INTRODUCTION:
Gas chromatography is the process of separating components
from the given crude drug by using a gaseous mobile phase.
The suggestion that separation of components of a mixture in
the gaseous state could be achieved using a gaseous mobile
phase was first given by Martin and Synge in 1941.
They suggested the use of gas-liquid partition chromatograms
for analytical purposes.
The first description of instrumentation and application was
made by James and Martin in 1952.
5
6. DEFINITION:
Gas chromatography is a separation technique based on partitioning
analytes between two immiscible phases: gaseous mobile phase (Carrier
gas) and a stationary solid or immobilized liquid phase (packed or hollow
capillary column).
Used for separation of volatile substances, or substances that can
be made volatile, from one another in a gaseous mixture at high
temperatures.
It involves a sample being vaporized and injected onto the head of the
chromatographic column. The sample is transported through the column by
the flow of inert, gaseous mobile phase. The column itself contains a liquid
stationary phase which is adsorbed onto the surface of an inert solid.
6
7. Gas Solid Chromatography(GSC)
The stationary phase is a solid. It is the affinity of solutes towards
adsorption onto the stationary phase which determines, in part, the
retention time. The mobile phase is, of course, a suitable carrier gas. This
gas chromatographic technique is most useful for the separation and
analysis of gases like CH4, CO2, CO, ... etc.
Gas Liquid Chromatography(GLC)
The stationary phase is immobilized liquid with very low volatility while
the mobile phase is a suitable carrier gas. GLC is the most widely used
technique for separation of volatile species.
Types of Gas Chromatography: 7
8. PRINCIPLE:
The sample solution injected into the instrument enters a gas stream
which transports the sample into a separation tube “column”. (Helium
or nitrogen is used as carrier gas.)
The various components are separated inside the column. The
detector measures the quantity of the components that exit the
column.
To measure a sample with an unknown concentration, a standard
sample with known concentration is injected into the instrument.
The standard sample peak, retention time (appearance time) and
area are compared to the test sample to calculate the concentration.
8
10. COMPONENTS OF GAS CHROMATOGRAPH
Carrier gas
Flow
meter
Injectors
Column
Oven
Detector• Flame ionization (FID)
• Thermal conductivity (TCD)
• Electron capture (ECD)
• Nitrogen-phosphorus
• Flame photometric (FPD)
• Photo-ionization (PID)
• Atomic emission (AED)
• GC-MS
Recorder
Detector types
10
11. CARRIER GAS (Mobile phase):
Sole purpose is to transport solutes (sample molecules) through the column
Commonly used carrier gases are He, N₂, H₂, Ar & CO₂
Should have following properties:
Chemically inert with stationary phase
Of High purity >99.9%
Good thermal conductivity
Compatible with detector
Higher density
Cheap and available
Non flammable
Non toxic
Non polar because stationary phase is polar
11
12. Molecular sieves:
A molecular sieve is a material with very small holes of precise
and uniform size. These holes are small enough to block large
molecules and allow small molecules to pass. Many molecular
sieves are used as desiccants.
Glass tubes filled with specific adsorbent materials to remove
impurities ( moisture, hydrocarbon, O2) from gas (mobile phase).
Used to avoid undesirable chemical changes into sample
components and stationary phase, or adverse effects on detector
performance.
12
13. Common contaminants and means of removing them are:
Air or oxygen: at levels above about 10 ppm, is removed by a
cartridge containing oxygen trap. Oxygen trap is filled with 500
cc of active oxygen adsorbent that binds covalently with
oxygen
Hydrocarbons:
removed by a cartridge containing activated carbon.
This molecular sieve use activated charcoal in-line trap to
remove gaseous hydrocarbons
Water vapors (moisture): removed with moisture filter.
Molecular sieves: 13
14. CARRIER GAS CYLINDER WITH MOLECULAR SIEVES
Moisture
filter
Hydrocorbon
filter
Indicating Oxygen
filter
Molecular sieves
Two-stage regulator
Tank
On/off valve
14
15. Gas filters required for a GC instrument with Flame Ionization (FID)
detector.
15
16. FLOW METER:
May be a ROTAMETER or a SOAP BUBBLE FLOW METER or a AIR BUBBLE
METER.
Have following properties:
Deliver the gas with uniform pressure/ flow rate.
Maintains the gas pressure and flow of gas per minute.
Adjusts the gas pressure at 10--50 psi.
Adjusts the gas flow
• in case of packed column at 25—150 ml/min
• in case of open tubullar column at 1—25 ml/min
16
17. SAMPLE INJECTION SYSTEM:
FUNCTION:
Vaporize the sample
Introduce the gaseous sample onto column
Gaseous, liquid and solid samples are introduced rapidly into the flowing
mobile phase at the top of the column through an injection port using a
micro-syringe, micro pipette, valve or other device.
Type of injector depends upon the physical state of the sample
Temperature of the sample port maintained about 50ﹾC higher than the
boiling point of least volatile component
Vaporize sample without decomposing it
17
18. INJECTOR:
The injection port Is a hollow, heated, glass-lined cylinder
The injector is heated so that all components in the sample
will be vaporized.
If the temperature is too low, separation is poor and broad
spectral peaks should result or no peak develops at all.
If the injection temperature is too high, the specimen may
decompose or change its structure.
The temperature of the sample port is usually about 50°C
higher than the boiling point of the least volatile component
of the sample.
18
20. GC Injection Techniques:
Vaporizing:
The liquid sample is evaporated prior to be transferred to the
separation column.
Split injection
Split-less injection
Programmed temperature vaporization (PTV) injection.
Non-vaporizing:
The liquid sample evaporates into the separation column (or a
precolumn)
On-column injection
20
21. SEPTA:
Ensure optimal performance of your GC
instrument with bleed and temperature.
Made of low-bleed silicone, have
excellent mechanical properties, are
ideal for demanding GC and GC-MS
applications, and may be used reliably
up to 400 °C.
Septum must be replaced at least after
200 injections.
21
22. Split Injector (vaporizing-injector)
The split vent is open, very small
part of the sample go into the
column.
Use when analyzing high
concentration or neat samples.
Yields the sharpest peaks if the
split gas is properly mixed.
Standard for capillary columns.
split vent
open
22
23. Splitless Injector (vaporizing-injector)
The split vent is closed, most of the
sample go into the column.
When analyzing low concentration or
diluted samples.
Splitless times of ~ 1 minute are
typical.
Standard for capillary columns.
23
24. On-column injection:
Sample aliquots are directly introduced
onto the analytical column ( 0.2-0.5 ) at
low temperatures (60– 80°C).
On column injection is favored for an
analyte that can be thermally degradated
at the elevated heated split or split-less
mode (around 200 C).
These injection mode require careful
awareness to attain a good reproducibility.
A liner of the wider volume is favorable for
this injection.
24
25. Column:
The column is where the
chromatographic separation of the
sample occurs.
Several types of columns are available
for different chromatographic
applications:
It is coated with a stationary phase
which greatly influences the separation
of the compounds.
25
26. Columns:
Gas chromatography columns are of two designs:
packed and capillary.
Packed columns are typically a glass or stainless steel coil (typically
1-5 m total length and 5 mm inner diameter) that is filled with the
stationary phase, or a packing coated with the stationary phase.
Capillary columns are a thin fused-silica (purified silicate glass)
capillary (typically 10-100 m in length and 250 mm inner diameter)
that has the stationary phase coated on the inner surface.
Capillary columns provide much higher separation efficiency than
packed columns but are more easily overloaded by too much
sample.
26
27. Packed columns:
A glass or stainless steel coil
Solid particles either porous or non-
porous coated with thin (1 μm) film of
liquid
3 - 6 mm Internal diameter;
1 - 5 m length
Large sample capacity and used for
preparative work
Alumina, silica gel, zeolite and porous
polymers are used as adsorbent
27
28. Capillary or open tubular column:
Made by stainless-steel tube, glass, copper, cupronickel or fused silica
material
Kept in a suitable thermostat for maintaining a constant temperature.
Inner wall of the tube is coated with liquid or solid stationary phase
10—100m in length (normally 30—50m) and have internal diameter
near to 0.3mm (varies from 0.1—0.5mm) with internal wall thickness
0.1mm (immobilized liquid stationary phase)
Flexible and can be shaped into coils
Give better resolution, larger theoretical plate number, greater
sensitivity, smaller sample capacity
28
29. Types of Capillary column:
Wall coated open tubular column (WCOT)
Support coated open tubular column
(SCOT)
Porous layer open tubular column (PLOT)
Fused silica open tubular column (FSOT)
29
30. Wall coated open tubular column (WCOT):
Consist of a capillary tube
Walls are coated with liquid stationary phase.
Made by extending the inner wall of columns by substances
such as fused silica.
Porous layer open tubular column (PLOT):
30
31. Support coated open tubular column (SCOT)
The inner wall of the capillary is lined
with a thin layer of support material
Support material may be
diatomaceous earth
Stationary phase adsorbed on
support layer
Less efficient than packed columns
31
33. Fused silica open tubular column (FSOT):
A new type of WCOT column
33
34. Column temperature and oven:
The column is enclosed in an insulated and
thermostatically-controlled oven with a heater and
circulating fan to maintain a uniform temperature from
ambient to about 400ºC
Column temperature must be high enough to provide
sufficient vapor pressure for components of the sample to
be eluted in suitable time.
Temperature of the oven ranges from 5ºC--400ºC and
may decrease up to with -25ºC with cryogenic cooling
34
36. Detectors:
Numerous types of detectors available
Requirements: -
• Sensitive to the analytes of interest
• Compatible with the column, carrier gas, solvent, etc.
• Useful linear range
• GC Detectors have it’s own temperature control
• Measures response as a voltage or a current
• Short response time independent of flow rate
36
37. Detectors:
Some of the most commonly used detectors are
described below:
Thermal conductivity detector (TCD)
Flame ionization detector (FID)
Electron capture detector (ECD)
Flame photometric detector (FPD)
Atomic emission detector (AED)
GC-MS
Nitrogen phosphorous detector (NPD)
37
38. Thermal conductivity detector (TCD)
Known as Katharometer
Depends upon the thermal conductivity of the mobile phase
passing around a tungsten-rhenium filament
Senses changes in thermal conductivity of the column effluent
and compares it to a reference flow of carrier gas
Simple, non-destructive and employed for packed column
Used for detection of organic and inorganic species
Sensitivity is low
Not suitable for capillary gas chromatography
38
40. Flame ionization detector (FID):
Most frequently used detector in GC
Its operation is based on detection of ions from during combustion of
organic compounds in a hydrogen flame
Carbon dioxide and carbon monoxide are not detectable by FID
FID compatible carrier gases include nitrogen, helium and argon
Insensitive to non-hydrocarbons
Low detection limits
Gives 100 times better detection than TCD
Destructive technique to detect the components
40
42. Electron capture detector (ECD):
Working principle is electron capturing by the sample or
analyte
Sensitive to halogens, chlorinated insecticides, carbonyl
peroxides, nitro-compounds and organo-metallics
β-emitter nickle-63 is used to emit β-particles
Concentration of the analyte is proportional to degree of
electron capture
Sensitivity decreases with moisture
42
44. Flame photometric detector (FPD):
FDP uses a photomultiplier tube to detect spectral lines
of the samples
Examples (phosphorous, halogens, Sulphur, metals etc.)
as these are burned in hydrogen-air flame
Excited sample elements emit radiation of specific
wavelengths in the flame which are filtered and
measured by a photomultiplier tube
Analyze environmental samples
44
45. Atomic emission detector (AED):
Based on atomic emission of sample
Elements (N, S, P, Br, Cl, F, O C, Si, etc.) generate atomic emission spectra
and detected by a series of photomultiplier tubes or photo diode-array
photometer
Figure. Schematic of atomic emission detector.
45
46. GC-MS:
Gas Chromatography-Mass Spectrometry (GC-MS) is very powerful
analytical tool in which gas chromatograph is attached with mass
spectrometer.
Separation of sample components is based on their retention time
The separated components of sample exit from the GC column, enters
the ionization chamber of MS.
Sample components are ionized and these ionized fragments are
separated, accelerated and detected using their mass to charge ratio
(m/e).
This is the best detector which identifies the exact molecular mass of
every component.
46
50. Troubleshooting categories:
1. Baseline disturbances.
2. Irregular peak shapes or sizes.
3. Retention time shifts.
4. Loss of separation or resolution.
5. Quantitation difficulties.
6. Rapid column deteriorations.
7. Ghost peaks.
8. Broad solvent fronts.
50
51. Troubleshooting Tools:
1. An electronic leak detector
2. A flow meter
3. An accurate thermometer
4. A reliable analytical column
5. New syringes
6. Spare septa and high temperature septa
7. Spare ferrules
8. Detector cleaning solutions
9. Spare recorder and electrometer cables
10. Instrument manuals
51
52. Applications of GC:
Used for separation of hydrocarbons and refinery gases in petroleum industries
Determines minute quantities of herbicides, fertilizers and pesticides in
vegetables, fruits and animal tissues
Analyze environmental hazards substances
Analyze and separate aromas of flowers, beverages ingredients, contents of
food and flavor
Extensively used in pharmaceutical industries to check intermediates, purity of
samples and drugs assay
Important technique for forensic and clinical analysis, toxicological cases, fatty
acids, steroids, biological specimens and body secretions
52
53. Ensure quality of various industrial and agricultural products
Study reaction mechanism
Analyze detergents, soap, rubber products, resins, plastics,
binders, coatings & plasticizers and polymers
Used in the separation of radioactive products
High degree of resolution of GLC allows purity of a sample to be
checked
Applications of GC: 53