Presenter: DR ANURAG YADAV
Moderator: DR AVINASH S S
1
DrAnuragYadav
The word derived from Greek:
Initial described by Mikhail Tswett in 1903.
• colorChroma
• To writegraphein
2
DrAnuragYadav
CHROMATOGRAPHY
“Chromatography is a technique for separating
mixtures into their components in order to analyze,
identify, purify, and/or quantify the mixture or
components.”
Separate
• Analyze
• Identify
• Purify
• Quantify
ComponentsMixture 3
DrAnuragYadav
TERMINOLOGIES:
Chromatograph - equipment that enables a sophisticated
separation
EX. Gas chromatography or Liquid chromatography
Eluent - Fluid entering column/ solvent that carries the analyte.
Eluate - Mobile phase leaving the column.
Stationary phase - Immobilized phase
 Immobilized on the support particles or on the inner wall of
the column tubing.
 Examples : Silica layer - Thin Layer Chromatography
4
DrAnuragYadav
TERMINOLOGIES:
Mobile phase
Moves in a definite direction. Liquid (LC), Gas (GC).
 The mobile phase moves through the chromatography column (the
stationary phase) where the sample interacts with the stationary phase
and is separated.
Retention time : Time takes for a particular analyte to pass through the
system (from the column inlet to the detector) under set conditions.
Sample (Anylate) :Substance analyzed in chromatography.
Solvent : Any substance capable of solubilizing another
substance.
5
DrAnuragYadav
 Chromatogram
 Visual output of the chromatograph.
 Separation - Different peaks or patterns on the chromatogram
correspond to different components of the separated mixture.
6
DrAnuragYadav
CLASSIFICATION:
1. Based on supporting medium
2. Based on mobile & stationary phase
3. Based on mechanism of separation
7
DrAnuragYadav
1. BASED ON SUPPORTING MEDIUM
Supporting
medium
planar column
8
DrAnuragYadav
2. BASED ON MOBILE & STATIONARY PHASE:
MOBILE AND STATIONARY
PHASE
GC
GLC GSC
LC
LLC LSC
9
DrAnuragYadav
DEPENDING ON PHYSICAL PROPERTIES OF
STATIONARY PHASE
 LC – flat methods ( Paper chr , HPTLC , TLC )
- Column methods(open column LC, HPLC)
 GC – packed column
- wall coated column ( capillary )
10
DrAnuragYadav
3. BASED ON MECHANISM OF SEPARATION:
MECHANISM
ION
EXCHANGE
PARTITION
ADSORPTION
AFFINITY
SIZE
EXCLUSION
11
DrAnuragYadav
PLANAR CHROMATOGRAPHY:
 Based on principle of the partition
Chromatography.
“The differential distribution of solute between two
immiscible liquids on plane.”
12
DrAnuragYadav
 partition chromatography a process of separation of solutes utili
zing the partition of the solutes between two liquid phases, namely
the original solvent and the film of solvent.
When substance mixed
with immiscible solvent,it
will distribute such that,
At equilibirum the ratio of
its conc In two phase is
constant
13
DrAnuragYadav
 This ratio is termed as partition coefficient & is
characteristic of a particular substance for a given
pair of solvent.
14
DrAnuragYadav
TYPES OF PARTITION CHROMATOGRAPHY
 Normal phase
 Reverse phase: Ion suppression & Ion pair
chromatography
 Normal phase LC, stationary phase is polar & mobile
phase is non-polar. water is the stationary phase; hexane,
benzene, chloroform or butanol form the mobile phase.
 Reverse phase LC, stationary phase is non-polar (eg.
octadecyl silane packing in a column) and mobile phase
is polar (solvents like methanol, acetonitrile used in
column mode of chromatography). 15
DrAnuragYadav
ION-SUPPRESSION CHROMATOGRAPHY
 Ionic character of weakly acidic/basic→suppressed(by
modification of mobile phase PH →solutes become less
polar →interact with nonpolar stationary phase →reverse
phase chromatography
16
DrAnuragYadav
ION-PAIR CHROMATOGRAPHY
 Counter ion of analyte → added to mobile phase →ionic
pair with analyte →neutralysed analytes are separated by
reverse phase chromatography
 Uses : separation of therapeutic drugs & metabolites.
17
DrAnuragYadav
PAPER CHROMATOGRAPHY :
 Paper chromatography is a variant of partition
chromatography procedure in which the cellulose
support is in the form of a sheet or paper
 Cellulose contain a large amount of bound water even
when extensively dried
 Partitioning occurs between the bound water and the
developing solvent
 In paper chromatography the mixture to be separated is
spotted onto the paper and dried
18
DrAnuragYadav
TYPES :
 Paper chromatography.
 Ascending paper.
 Descending paper.
 Ascending-descending.
 Radial paper.
 Two-dimensional paper.
 Thin layer chromatography.
19
DrAnuragYadav
Paper Chromatography has different types or
modes:
Ascending chromatography: As
the name indicates, the
chromatogram ascends. Here the
development of paper occurs due
the solvent movement or travel in
upward direction on the paper.
Descending chromatography: Here the development of paper occurs
due to solvent travel downwards on the paper.
Ascending- descending mode: Here solvent first travels
upwards and then down wards on the paper. 20
DrAnuragYadav
Radial mode: Here the solvent travels from center(mid point) towards
periphery of Circular chromatography paper.
Two dimensional chromatography: Here
the chromatogram development occurs in
two directions at right angles.
21
DrAnuragYadav
INSTRUMENTATION
Chromatography jar
Capillary tube
Stationary phase (liquid impregnated paper)
Mobile phase
22
DrAnuragYadav
INSTRUMENTATION
Chromatography jar:
It is made of glass and has a lid on it. Jar maintains
proper environment that is required for separation.
Capillary tube:
It is used to apply sample mixture.
Stationary phase:
liquid impregnated paper
23
DrAnuragYadav
INSTRUMENTATION
Mobile phase:
Mobile phase may be a single liquid or a mixture of
liquids.
Commonly used mobile phases are;
 Methanol
 Ethanol
 Ethyl acetate
 Diethyl ether
 Acetone
 Chloroform 24
DrAnuragYadav
HOW TO PERFORM PAPER
CHROMATOGRAPHY?
25
DrAnuragYadav
1. PREPARING THE PAPER STRIPS
• Cut the filter paper into 5
x4 measurement.
• Draw a line 0.5 cm above
the bottom edge of the
strip with the pencil.
• Label each strip with its
corresponding solution.
•
• Place a spot from each
pen on your starting line.
26
DrAnuragYadav
2. DEVELOPING THE CHROMATOGRAMS
• Place the strips in the beakers.
• Make sure the solution does not come
above your start line.
• Keep the beakers covered.
• Let strips develop until the ascending
solution front is about 2 cm from the top
of the strip.
• Remove the strips and let them dry.
27
DrAnuragYadav
More polar!
Less polar!
solvent front
origin mixture
solvent front
component B
component A
origin
solvent front
component B
component A
origin
Increasing Development Time
28
DrAnuragYadav
VISUALIZATION OF CHROMATOGRAPHY
If the sample is separated into colored components, then
the location is dried in ordinary light. But in case of
colorless components following are used;
 Uv lamp
 Iodine crystals
 Spraying agents: Ninhydrin for aminoacids and
proteins , sulfuric acid for phospholipids ,
diphenylamine for sugars 29
DrAnuragYadav
DOCUMENTATION
Storage of chromatogram.
Calculating Rf values
 Calculate Rf value & interpret.
 Defined : “as the ratio of the distance travelled by
the substance & the distance travelled by solvent
front”
30
DrAnuragYadav
RF VALUE IMPORTANCE:
 Ratio of distance travelled by the solute to the
distance travelled by the solvent
 Rf value is constant for a particular solvent system
at a given temperature
 Spots of the unknown substance can be identified
by comparing those of the pure standards
31
DrAnuragYadav
APPLICATIONS
It is used for separation and identification of;
Amino acids
Carbohydrates
Tannins
Glycosides
Alkaloids etc.
32
DrAnuragYadav
THIN-LAYER CHROMATOGRAPHY (TLC)
“ The technique which involves flowing of mobile phase over a
thin layer of adsorbent, applied on solid support, where
separation of components occur by differential migration
which occurs when solvent flows along fine powder spread on
glass plates, is called thin –layer chromatography.”
 Silica / Alumina layered over a glass plate ----- uniform thin
layer(0.2mm)
 Procedure same as that for paper
chromatography.
 Better resolution
 HPTLC: particle size-4.5μm. 33
DrAnuragYadav
Instrumentation:
 Chromatography jar
 Capillary tube
 Thin layer chromatography plate
 Stationary phase
 Mobile phase
34
DrAnuragYadav
Chromatography jar:
 It is made of glass and has a lid on
it.
 Jar maintains proper environment
that is required for separation.
Capillary tube:
 It is used to apply sample mixture
on TLC plate.
TLC plate:
 Borosilicate glass plates are
preferred. Most commonly used
sizes are;
 20 X 20cm
 20 X 10cm
 20 X 5cm
Mobile phase:
Mobile phase may be a single
liquid or a mixture of liquids.
Commonly used mobile phases
are;
Methanol
Ethanol
Ethyl acetate
Diethyl ether
Acetone
Chloroform
35
DrAnuragYadav
 Procedure
 Location Of Separated Components
 Documentation
36
DrAnuragYadav
APPLICATION:
It is used for separation and identification of;
 Amino acids
 Peptides and proteins
 Alkaloids
 Carbohydrates
 Fats and fatty acids
 Antibiotics
 Narcotic analgesics
 Glycosides 37
DrAnuragYadav
ADVANTAGES OF TLC
 Simple
 Rapid
 Ability to process large number of samples in minimal
time
 Low cost in terms of reagent & equipment.
38
DrAnuragYadav
APPLICATIONS OF CHROMATOGRAPHY.
• In clinical diagnosis : detection & estimation of amino
acids, metabolites, sugars, mucopolysaccharides in urine
& blood.
• Useful for screening and diagnosis of inborn metabolic
disorders : Aminoacidurias, hemoglobinopathies,
mucopolysaccharidoses, etc.
39
DrAnuragYadav
APPLICATIONS OF CHROMATOGRAPHY
 In clinical diagnosis
Paper chromatography,TLC –qualitative
HPLC, GC –For quantitation
 In clinical diagnosis
Assay of Hormones, drugs, vitamins,
metabolites ---HPLC and GC
40
DrAnuragYadav
APPLICATIONS OF CHROMATOGRAPHY
 Chromatography in protein research –
1) Purification –adsorption, ion exchange ,affinity, gel
filtration chromatography.
2) Sequencing – ion-exchange chromatography.
3) Mol.wt. determination – gel filtration chromatography.
41
DrAnuragYadav
TROUBLESHOOTING
 It seems to be easy procedure, but error do
occur like;
- Compound runs as streak rather than spot
(sample was overloaded)
- Sample run as smear/upward crescent :
compound possess strongly acidic or basic
group- add few drops of ammonium hydroxide
or acetic acid to the solvent.
- Sample runs downward crescent- adsorbent
was disturbed during spotting.
streak
More polar
Cross placed
Less sample
Normal
42
DrAnuragYadav
- Plate solvent front runs crookedly:
either the adsorbent has flaked off the sides
or the side of plate are touching sides of
container.
- Many random spots
- No spots are seen on plate
- Blur blue spots on plate : use of ink pen
instead of pencil to mark the origin.
streak
More polar
Cross placed
Less sample
Normal
43
DrAnuragYadav
44
DrAnuragYadav
45
DrAnuragYadav
 ADSORBENTS:
 “ An adsorbent is a substance, usually porous in nature and with a high surface area that can adsorb substances onto its surface by intermolecular forces.”

 AN IDEAL ADSORBENT:
 The Ideal adsorbent must fulfill the following requirements:

 Insoluble in mobile phase
 Inert to solutes (adsorptive)
 Colorless especially when work with colored mixtures
 Suitable particle size enough to give good separation and reasonable flow rate
 COMMON ADSORBENTS:
 Hydrated silica gel
 Silica gel G
 Silica gel S
 Silica gel GF 254
 Silica gel H
 Silica gel N
 Silica gel HF 254
 Silica gel PF 254
 Modified silica gel
 Alumina
 Kieselghur (Diatomaceous earth)
 Cellulose MN 300
 Cellulose microcrystalline
46
DrAnuragYadav
THIN LAYER CHROMATOGRAPHY (TLC)
 In TLC, any substance that can be finely divided and
formed into a uniform layer can be used.
 Both organic and inorganic substances can be used
to form a uniform layer for TLC.
 Organic substances include: cellulose, polyamide,
polyethylene
 Inorganic: silica gel, aluminum oxide and magnesium
silicate
47
DrAnuragYadav
THIN-LAYER CHROMATOGRAPHY: A
TWO-COMPONENT MIXTURE
More polar!
Less polar!
solvent front
origin mixture
solvent front
component B
component A
origin
solvent front
component B
component A
origin
Increasing Development Time
48
DrAnuragYadav
APPLICATIONS
1. Separation of carbohydrates:
Mobile phase:
acetonitrile : water (85:15)
Detection:
sulfuric acid : methanol (1:3)
heat for 10 min at 110 C to see
brown spots
49
DrAnuragYadav
Separation of Total Lipid into
different Classes
Mobile Phase: hexane: diethyl ether: formic acid (80:20:2)
Cholesteryl esters
TAG
Free fatty acids
Cholesterol
1,3-DAG
1,2-DAG
Monoacyl glycerols
Phospholipids
50
DrAnuragYadav
Separation of Triacylglycerols
Mobile Phase: Pet ether: diethyl ether: acetic acid (90:9:1)
Tristearin
2-oleodistearin
1-stereodiolein
Triolein
Trolinolein
With HUFA
51
DrAnuragYadav

Chromatography by Dr. Anurag Yadav

  • 1.
    Presenter: DR ANURAGYADAV Moderator: DR AVINASH S S 1 DrAnuragYadav
  • 2.
    The word derivedfrom Greek: Initial described by Mikhail Tswett in 1903. • colorChroma • To writegraphein 2 DrAnuragYadav
  • 3.
    CHROMATOGRAPHY “Chromatography is atechnique for separating mixtures into their components in order to analyze, identify, purify, and/or quantify the mixture or components.” Separate • Analyze • Identify • Purify • Quantify ComponentsMixture 3 DrAnuragYadav
  • 4.
    TERMINOLOGIES: Chromatograph - equipmentthat enables a sophisticated separation EX. Gas chromatography or Liquid chromatography Eluent - Fluid entering column/ solvent that carries the analyte. Eluate - Mobile phase leaving the column. Stationary phase - Immobilized phase  Immobilized on the support particles or on the inner wall of the column tubing.  Examples : Silica layer - Thin Layer Chromatography 4 DrAnuragYadav
  • 5.
    TERMINOLOGIES: Mobile phase Moves ina definite direction. Liquid (LC), Gas (GC).  The mobile phase moves through the chromatography column (the stationary phase) where the sample interacts with the stationary phase and is separated. Retention time : Time takes for a particular analyte to pass through the system (from the column inlet to the detector) under set conditions. Sample (Anylate) :Substance analyzed in chromatography. Solvent : Any substance capable of solubilizing another substance. 5 DrAnuragYadav
  • 6.
     Chromatogram  Visualoutput of the chromatograph.  Separation - Different peaks or patterns on the chromatogram correspond to different components of the separated mixture. 6 DrAnuragYadav
  • 7.
    CLASSIFICATION: 1. Based onsupporting medium 2. Based on mobile & stationary phase 3. Based on mechanism of separation 7 DrAnuragYadav
  • 8.
    1. BASED ONSUPPORTING MEDIUM Supporting medium planar column 8 DrAnuragYadav
  • 9.
    2. BASED ONMOBILE & STATIONARY PHASE: MOBILE AND STATIONARY PHASE GC GLC GSC LC LLC LSC 9 DrAnuragYadav
  • 10.
    DEPENDING ON PHYSICALPROPERTIES OF STATIONARY PHASE  LC – flat methods ( Paper chr , HPTLC , TLC ) - Column methods(open column LC, HPLC)  GC – packed column - wall coated column ( capillary ) 10 DrAnuragYadav
  • 11.
    3. BASED ONMECHANISM OF SEPARATION: MECHANISM ION EXCHANGE PARTITION ADSORPTION AFFINITY SIZE EXCLUSION 11 DrAnuragYadav
  • 12.
    PLANAR CHROMATOGRAPHY:  Basedon principle of the partition Chromatography. “The differential distribution of solute between two immiscible liquids on plane.” 12 DrAnuragYadav
  • 13.
     partition chromatographya process of separation of solutes utili zing the partition of the solutes between two liquid phases, namely the original solvent and the film of solvent. When substance mixed with immiscible solvent,it will distribute such that, At equilibirum the ratio of its conc In two phase is constant 13 DrAnuragYadav
  • 14.
     This ratiois termed as partition coefficient & is characteristic of a particular substance for a given pair of solvent. 14 DrAnuragYadav
  • 15.
    TYPES OF PARTITIONCHROMATOGRAPHY  Normal phase  Reverse phase: Ion suppression & Ion pair chromatography  Normal phase LC, stationary phase is polar & mobile phase is non-polar. water is the stationary phase; hexane, benzene, chloroform or butanol form the mobile phase.  Reverse phase LC, stationary phase is non-polar (eg. octadecyl silane packing in a column) and mobile phase is polar (solvents like methanol, acetonitrile used in column mode of chromatography). 15 DrAnuragYadav
  • 16.
    ION-SUPPRESSION CHROMATOGRAPHY  Ioniccharacter of weakly acidic/basic→suppressed(by modification of mobile phase PH →solutes become less polar →interact with nonpolar stationary phase →reverse phase chromatography 16 DrAnuragYadav
  • 17.
    ION-PAIR CHROMATOGRAPHY  Counterion of analyte → added to mobile phase →ionic pair with analyte →neutralysed analytes are separated by reverse phase chromatography  Uses : separation of therapeutic drugs & metabolites. 17 DrAnuragYadav
  • 18.
    PAPER CHROMATOGRAPHY : Paper chromatography is a variant of partition chromatography procedure in which the cellulose support is in the form of a sheet or paper  Cellulose contain a large amount of bound water even when extensively dried  Partitioning occurs between the bound water and the developing solvent  In paper chromatography the mixture to be separated is spotted onto the paper and dried 18 DrAnuragYadav
  • 19.
    TYPES :  Paperchromatography.  Ascending paper.  Descending paper.  Ascending-descending.  Radial paper.  Two-dimensional paper.  Thin layer chromatography. 19 DrAnuragYadav
  • 20.
    Paper Chromatography hasdifferent types or modes: Ascending chromatography: As the name indicates, the chromatogram ascends. Here the development of paper occurs due the solvent movement or travel in upward direction on the paper. Descending chromatography: Here the development of paper occurs due to solvent travel downwards on the paper. Ascending- descending mode: Here solvent first travels upwards and then down wards on the paper. 20 DrAnuragYadav
  • 21.
    Radial mode: Herethe solvent travels from center(mid point) towards periphery of Circular chromatography paper. Two dimensional chromatography: Here the chromatogram development occurs in two directions at right angles. 21 DrAnuragYadav
  • 22.
    INSTRUMENTATION Chromatography jar Capillary tube Stationaryphase (liquid impregnated paper) Mobile phase 22 DrAnuragYadav
  • 23.
    INSTRUMENTATION Chromatography jar: It ismade of glass and has a lid on it. Jar maintains proper environment that is required for separation. Capillary tube: It is used to apply sample mixture. Stationary phase: liquid impregnated paper 23 DrAnuragYadav
  • 24.
    INSTRUMENTATION Mobile phase: Mobile phasemay be a single liquid or a mixture of liquids. Commonly used mobile phases are;  Methanol  Ethanol  Ethyl acetate  Diethyl ether  Acetone  Chloroform 24 DrAnuragYadav
  • 25.
    HOW TO PERFORMPAPER CHROMATOGRAPHY? 25 DrAnuragYadav
  • 26.
    1. PREPARING THEPAPER STRIPS • Cut the filter paper into 5 x4 measurement. • Draw a line 0.5 cm above the bottom edge of the strip with the pencil. • Label each strip with its corresponding solution. • • Place a spot from each pen on your starting line. 26 DrAnuragYadav
  • 27.
    2. DEVELOPING THECHROMATOGRAMS • Place the strips in the beakers. • Make sure the solution does not come above your start line. • Keep the beakers covered. • Let strips develop until the ascending solution front is about 2 cm from the top of the strip. • Remove the strips and let them dry. 27 DrAnuragYadav
  • 28.
    More polar! Less polar! solventfront origin mixture solvent front component B component A origin solvent front component B component A origin Increasing Development Time 28 DrAnuragYadav
  • 29.
    VISUALIZATION OF CHROMATOGRAPHY Ifthe sample is separated into colored components, then the location is dried in ordinary light. But in case of colorless components following are used;  Uv lamp  Iodine crystals  Spraying agents: Ninhydrin for aminoacids and proteins , sulfuric acid for phospholipids , diphenylamine for sugars 29 DrAnuragYadav
  • 30.
    DOCUMENTATION Storage of chromatogram. CalculatingRf values  Calculate Rf value & interpret.  Defined : “as the ratio of the distance travelled by the substance & the distance travelled by solvent front” 30 DrAnuragYadav
  • 31.
    RF VALUE IMPORTANCE: Ratio of distance travelled by the solute to the distance travelled by the solvent  Rf value is constant for a particular solvent system at a given temperature  Spots of the unknown substance can be identified by comparing those of the pure standards 31 DrAnuragYadav
  • 32.
    APPLICATIONS It is usedfor separation and identification of; Amino acids Carbohydrates Tannins Glycosides Alkaloids etc. 32 DrAnuragYadav
  • 33.
    THIN-LAYER CHROMATOGRAPHY (TLC) “The technique which involves flowing of mobile phase over a thin layer of adsorbent, applied on solid support, where separation of components occur by differential migration which occurs when solvent flows along fine powder spread on glass plates, is called thin –layer chromatography.”  Silica / Alumina layered over a glass plate ----- uniform thin layer(0.2mm)  Procedure same as that for paper chromatography.  Better resolution  HPTLC: particle size-4.5μm. 33 DrAnuragYadav
  • 34.
    Instrumentation:  Chromatography jar Capillary tube  Thin layer chromatography plate  Stationary phase  Mobile phase 34 DrAnuragYadav
  • 35.
    Chromatography jar:  Itis made of glass and has a lid on it.  Jar maintains proper environment that is required for separation. Capillary tube:  It is used to apply sample mixture on TLC plate. TLC plate:  Borosilicate glass plates are preferred. Most commonly used sizes are;  20 X 20cm  20 X 10cm  20 X 5cm Mobile phase: Mobile phase may be a single liquid or a mixture of liquids. Commonly used mobile phases are; Methanol Ethanol Ethyl acetate Diethyl ether Acetone Chloroform 35 DrAnuragYadav
  • 36.
     Procedure  LocationOf Separated Components  Documentation 36 DrAnuragYadav
  • 37.
    APPLICATION: It is usedfor separation and identification of;  Amino acids  Peptides and proteins  Alkaloids  Carbohydrates  Fats and fatty acids  Antibiotics  Narcotic analgesics  Glycosides 37 DrAnuragYadav
  • 38.
    ADVANTAGES OF TLC Simple  Rapid  Ability to process large number of samples in minimal time  Low cost in terms of reagent & equipment. 38 DrAnuragYadav
  • 39.
    APPLICATIONS OF CHROMATOGRAPHY. •In clinical diagnosis : detection & estimation of amino acids, metabolites, sugars, mucopolysaccharides in urine & blood. • Useful for screening and diagnosis of inborn metabolic disorders : Aminoacidurias, hemoglobinopathies, mucopolysaccharidoses, etc. 39 DrAnuragYadav
  • 40.
    APPLICATIONS OF CHROMATOGRAPHY In clinical diagnosis Paper chromatography,TLC –qualitative HPLC, GC –For quantitation  In clinical diagnosis Assay of Hormones, drugs, vitamins, metabolites ---HPLC and GC 40 DrAnuragYadav
  • 41.
    APPLICATIONS OF CHROMATOGRAPHY Chromatography in protein research – 1) Purification –adsorption, ion exchange ,affinity, gel filtration chromatography. 2) Sequencing – ion-exchange chromatography. 3) Mol.wt. determination – gel filtration chromatography. 41 DrAnuragYadav
  • 42.
    TROUBLESHOOTING  It seemsto be easy procedure, but error do occur like; - Compound runs as streak rather than spot (sample was overloaded) - Sample run as smear/upward crescent : compound possess strongly acidic or basic group- add few drops of ammonium hydroxide or acetic acid to the solvent. - Sample runs downward crescent- adsorbent was disturbed during spotting. streak More polar Cross placed Less sample Normal 42 DrAnuragYadav
  • 43.
    - Plate solventfront runs crookedly: either the adsorbent has flaked off the sides or the side of plate are touching sides of container. - Many random spots - No spots are seen on plate - Blur blue spots on plate : use of ink pen instead of pencil to mark the origin. streak More polar Cross placed Less sample Normal 43 DrAnuragYadav
  • 44.
  • 45.
  • 46.
     ADSORBENTS:  “An adsorbent is a substance, usually porous in nature and with a high surface area that can adsorb substances onto its surface by intermolecular forces.”   AN IDEAL ADSORBENT:  The Ideal adsorbent must fulfill the following requirements:   Insoluble in mobile phase  Inert to solutes (adsorptive)  Colorless especially when work with colored mixtures  Suitable particle size enough to give good separation and reasonable flow rate  COMMON ADSORBENTS:  Hydrated silica gel  Silica gel G  Silica gel S  Silica gel GF 254  Silica gel H  Silica gel N  Silica gel HF 254  Silica gel PF 254  Modified silica gel  Alumina  Kieselghur (Diatomaceous earth)  Cellulose MN 300  Cellulose microcrystalline 46 DrAnuragYadav
  • 47.
    THIN LAYER CHROMATOGRAPHY(TLC)  In TLC, any substance that can be finely divided and formed into a uniform layer can be used.  Both organic and inorganic substances can be used to form a uniform layer for TLC.  Organic substances include: cellulose, polyamide, polyethylene  Inorganic: silica gel, aluminum oxide and magnesium silicate 47 DrAnuragYadav
  • 48.
    THIN-LAYER CHROMATOGRAPHY: A TWO-COMPONENTMIXTURE More polar! Less polar! solvent front origin mixture solvent front component B component A origin solvent front component B component A origin Increasing Development Time 48 DrAnuragYadav
  • 49.
    APPLICATIONS 1. Separation ofcarbohydrates: Mobile phase: acetonitrile : water (85:15) Detection: sulfuric acid : methanol (1:3) heat for 10 min at 110 C to see brown spots 49 DrAnuragYadav
  • 50.
    Separation of TotalLipid into different Classes Mobile Phase: hexane: diethyl ether: formic acid (80:20:2) Cholesteryl esters TAG Free fatty acids Cholesterol 1,3-DAG 1,2-DAG Monoacyl glycerols Phospholipids 50 DrAnuragYadav
  • 51.
    Separation of Triacylglycerols MobilePhase: Pet ether: diethyl ether: acetic acid (90:9:1) Tristearin 2-oleodistearin 1-stereodiolein Triolein Trolinolein With HUFA 51 DrAnuragYadav

Editor's Notes

  • #43 All of the above (including the procedure page) might sound like TLC is quite an easy procedure. But what about the first time you run a TLC, and see spots everywhere and blurred, streaked spots? As with any technique, with practice you get better. One thing you have to be careful Examples of common problems encountered in TLC:The compound runs as a streak rather than a spot The sample was overloaded. Run the TLC again after diluting your sample. Or, your sample might just contain many components, creating many spots which run together and appear as a streak. Perhaps, the experiment did not go as well as expected. The sample runs as a smear or a upward crescent. Compounds which possess strongly acidic or basic groups (amines or carboxylic acids) sometimes show up on a TLC plate with this behavior. Add a few drops of ammonium hydroxide (amines) or acetic acid (carboxylic acids) to the eluting solvent to obtain clearer plates. The sample runs as a downward crescent. Likely, the adsorbent was disturbed during the spotting, causing the crescent shape.
  • #44 The plate solvent front runs crookedly. Either the adsorbent has flaked off the sides of the plate or the sides of the plate are touching the sides of the container (or the paper used to saturate the container) as the plate develops. Crookedly run plates make it harder to measure Rf values accurately. Many, random spots are seen on the plate. Make sure that you do not accidentally drop any organic compound on the plate. If get a TLC plate and leave it laying on your workbench as you do the experiment, you might drop or splash an organic compound on the plate. No spots are seen on the plate. You might not have spotted enough compound, perhaps because the solution of the compound is too dilute. Try concentrating the solution, or, spot it several times in one place, allowing the solvent to dry between applications. Some compounds do not show up under UV light; try another method of visualizing the plate. Or, perhaps you do not have any compound because your experiment did not go as well as planned. If the solvent level in the developing jar is deeper than the origin (spotting line) of the TLC plate, the solvent will dissolve the compounds into the solvent reservoir instead of allowing them to move up the plate by capillary action. Thus, you will not see spots after the plate is developed. You see a blur of blue spots on the plate as it develops. Perhaps, you used an ink pen instead of a pencil to mark the origin?