sumit ppt

Recent Development In Chromatography: 

Recent Development In Chromatography By: vivek Swarnkar M.Pharm ( I st year) p’ceutical Analysis

PowerPoint Presentation: 

1903 – Tswett , a Russian botanist coined the term chromatography. He passed plant tissue extracts through a chalk column to separate pigments by differential adsorption chromatogrpahy 1915 R.M Willstatter , German Chemist win Nobel Prize for similar experiement 1922 L.S Palmer , American scientist used Tswett’s techniques on various natural products 1931 Richard Kuhn used chromatography to separate isomers of polyene pigments; this is the first known acceptance of chromatographic methods Brief History of Chromatography

PowerPoint Presentation: 

IUPAC Definition: The International Union Of Pure and Applied Chemistry (IUPAC) has drafted a recommended definition of chromatography “ Chromatography is a physical method of separation in which the components to be separated are distributed between two phases ,one of which is stationary (stationary phase), while the other (the mobile phase) moves in a define direction ”

PowerPoint Presentation: 

1. Gas chromatography Gas- Liq Chromatography Gas-solid Chromatography (S)-liquid adsorbed or bonded to (S) Solid a stationary phase partition adsorption Classification of chromatographic method 1. Gas chromatography(GC) 2. Liquid chromatography(LC) 3. Supercritical fluid chromatography (SFC)

PowerPoint Presentation: 

2. Liquid Chromatography Liq-liq Chromatograpy Ion-exchange Chromatography Affinity Chr. (S)-Liq-adsorbed or bonded (S)-Ion exchange resin (S)-liq bonded to a solid surface to a stationary phase liq-solid chromatography size-exclusion chromatography (S)-solid (S)-liquid is interstices of a polymeric solid partition Ion exchange Partition b/w surface liquid &mobile liquid adsorption Partition b/w immiscible liquids

3. Supercritical fluid chromatography (SFC) (M) –supercriticle fluid (S) –organic species bonded to a solid surface : 

3. Supercritical fluid chromatography (SFC) (M) – supercriticle fluid (S) –organic species bonded to a solid surface Partition between supercritical fluid and bonded surface

Modern techniques: 

Modern techniques 1.Counter Current Chromatography (CCC):- 2.Recent development in gas chromatography 1. Droplet Counter Current Chromatography (DCCC) 2. High speed counter current chromatography(HSCCC) 3. Centrifugal Partition Chromatography (CPC) 4.Elution Extrusion Counter current chromatography (EECCC) 1.Head space gas chromatography 2.Pyrolysis gas chromatography 3.High speed resolution capillary gas chromatography 4.Multidimensional chromatography comprehensive two dimensional chromatography 3.chiral chromatography 4. latest development in HPLC

(a) Counter Current Chromatography (CCC) : 

(a) Counter Current Chromatography (CCC) Counter current chromatography (CCC) is a liquid chromatography technique in which the stationary phase is also a liquid. The solute separation is based on partitioning between the two immiscible liquid phases : the mobile phase and the support-free liquid stationary phase. History Countercurrent chromatography, has its origins in the work of (Martin and Synge,1941; Synge, 1946) carried out in Britain during world war II. For their pioneering work, Martin and Synge shared the 1952 Nobel Prize in Chemistry. types of ccc :- 1. Droplet Counter Current Chromatography (DCCC) 2. High speed counter current chromatography(HSCCC) 3. Centrifugal Partition Chromatography (CPC) 4.Elution Extrusion Counter current chromatography (EECCC)

: 

Partition Coefficient For a given substance “A” the partition coefficient is defined as: Κ A = [A] upper phase/[A] lower phase Κ A is a constant at any given temperature It is unaffected by the presence of other substances or concentration of the solute Select Solvent systems with K values of the target compounds in a proper range: The suitable K values for CCC are 0.5 ≤ K ≤ 1.0.

Droplet countercurrent chromatography (DCCC) : 

Droplet countercurrent chromatography (DCCC) The apparatus consists of a set of vertical straight tubes serially connected with narrow transfer tubing. The original CCC apparatus is equipped with 300 glass tubes each 60 cm×1.8 mm The total capacity is about 600 ml The operation of DCCC is initiated by filling the entire column with the stationary phase of an equilibrated two-phase solvent system followed by injection of sample solution.

PowerPoint Presentation: 

Consequently, the solutes are separated according to their partition coefficient. As with all chromatography, compounds more soluble in the MP will move more quickly, while those more soluble in the SP will lag behind. Under the optimum flow rate, the mobile phase forms multiple droplets into the stationary phase to divide the column space into numerous partition units and this process is repeated in each partition unit. Then, the other phase is introduced into the first unit in such a way that the mobile phase can travel through the column of the stationary phase by the effect of gravity, i.e. the mobile phase is introduced from the bottom if it is the lighter phase, and from the top if it is the heavier phase.

PowerPoint Presentation: 

Applications of Droplet Counter – Current Chromatography (DCCC) 1 Seaparation of chromone and flavon. 2.Separation of glycosides ruberythric acid and lucidin primeveroside by DCCC. 3. Plant antiviral agents:- Isolation of antiviral phenolic glucosides from Populus cultivar Beaupre 4. Separation of non-polar compounds 5. Isolation of virginiamycin-M1 6. Isolation of parthenolide 7. Isolation of vitamin B12 8. Separation of a complex alkaloid extract:- Macrocyclic pyrrolizidine alkaloids from Senecio anonymus. Limitations or disadvantages of DCCC Extremely low flow rates (some times solute retention is measured in days.) It has limitation to use only those biphasic solvents systems, which form stable droplets. Poor mixing of phases, which results in relatively low efficiency.

Modern counter current chromatography: 

Modern counter current chromatography High speed counter current chromatography (HSCCC) Centrifugal Partition Chromatography (CPC) It employs a constant gravity field produced by a single axis rotation , together with rotatory seals for supply of solvent . It is hydrostatic equilibrium system. It involves variable gravity field produced by double axis gyratory motion & seal free arrangement for column. It is a hydrodynamic equilibrium system .

Working of modern techniques (CCP,HPCCC): 

Working of modern techniques (CCP,HPCCC) The planetary motion is produced by a engaging a planetary gear mounted on the column holder axis to an identical stationary sun gear rigidly fixed to the centrifuge frame work . 1:1 gear system produces a perticular type of planetary motion of the column holder . i.e. the holder rotates about it’s axis while revolving around the centrifuge axis at the same angular velocity in the same direction . Planetary motion provides two major function Produces a unique hydrodynamic motion of two solvent phases within the rotating multilayer coiled column mainly due to a Archimedean screw effect Rotary-seal-free elution system so that the mobile phase is continuously eluted through the rotating separation column.

when two solvent phases introduced in an end closed colied column the rotation separates the two phase completely along the length of the tube where the lighter phase occupied at head and heavier phase at tail end .: 

when two solvent phases introduced in an end closed colied column the rotation separates the two phase completely along the length of the tube where the lighter phase occupied at head and heavier phase at tail end . This condition indicates that the white phase (lighter) introduced at the tail end it will move towards the head and similarly the black (heavier) phase introduced at the head it will move towards tail

The motion and distribution of the two phases in the rotating coil were observed under stroboscopic illumination: 

The motion and distribution of the two phases in the rotating coil were observed under stroboscopic illumination STROBOSCOPIC illumination Spiral column undergoes type-J planetary motion. Area of the spiral column zone 1).Mixing zone 2).Settling zone Occupying area about one quarter Of the area near the centre of revolution Rest of the area In Fig. B, the spiral column is stretched and arranged according to the positions I–IV to visualize the motion of the mixing zones along the tubing. It clearly indicates that each mixing zone travels through the spiral column at a rate of one round per one revolution .

Conclusion :-: 

Conclusion :- It indicates the important fact that the solute in the spiral column is subjected to the repetitive partition process of mixing and settling at an enormously high rate of over 13times per second ( at 800 rpm ). It demonstrates the high efficiency of HSCCC. Inner working of cpc

Sample solution : 

Sample solution The sample for HSCCC/CPC may be dissolved directly in the stationary phase or in a mixture of the two phases. Sample volume may be less than 5% of the total column capacity. Larger sample volume into the column will reduce peak resolution of the analytes We must understand the head–tail orientation of the separation column. A lower (heavier) mobile phase should be introduced through the head toward the tail, and an upper (lighter) mobile phase in the opposite direction. This is extremely important because the elution of either phase in the wrong direction results in an almost complete loss of the stationary phase from the column. Separation column

PowerPoint Presentation: 

The optimum revolution speed (revolution and planetary rotation speeds are always same) for the commercial HSCCC/CPC instrument for preparative separation ranges between 600 and 1400 rpm. Use of a lower speed will reduce the volume of the stationary phase retained in the column leading to lower peak resolution. On the other hand, the higher speeds may produce excessive sample band broadening by violent pulsation of the column because of elevated pressure. Flow rate of the mobile phase The flow rate of the mobile phase determines the separation time , the amount of stationary phase retained in the column, and therefore the peak resolution. For the commercial multilayer coil are as follows: 5–6 ml/min 1 ml/min for an analytical column Applications in the Following Industries 1. Fine Chemicals 2. Pharmaceutical 3. Bio-Medical 4. Biotechnology 5. Fats and Oils 6. Fermentation Revolution speed

Compounds That Can Be Isolated in High Purity by HSCCC/CPC Technologies: 

Compounds That Can Be Isolated in High Purity by HSCCC/CPC Technologies 1. Saponins:- Ginsenosides (a) CHCl3–MeOH–2-BuOH–H2O (5:6:1:4) (b) EtOAc–1-BuOH–H2O Upper (1:1:2) 2. Chlorophylls 3. Catechins :- Epigallocatechin n-Hexane–EtOAc–H2O Lower (1:9:10) Tea catechins n-Hexane–EtOAc–MeOH–H2O Lower (3:10:3:10) It is isolate by cpc & purity was determine by HPLC 4. Fat soluble vitamins 5. Anthocyanins:- Bilberry anthocyanins MTBE–1-BuOH–CH3CN–H2O–TFA Lower (1:4:1:5:0.01) 6. Phenolic compounds 7. Alkaloids:- Isolation of indole alkaloids from Catharanthus roseus by centrifugal partition chromatography in the pH-zone refining mode This mode allowed a preparative and efficient isolation of vindoline , vindolinine , catharanthine and vincaleukoblastine from a crude mixture of Catharanthus roseus alkaloids. 8. Phospholipids 9. Lignans 10. Purification of Arachidonic Acid By CPC

PowerPoint Presentation: 

11. Mono/Oligo-saccharides 12. Purification of coenzyme Q10 from fermentation extract: HSCCC versus silica gel column chromatography HSCCC was applied to the purification of coenzyme Q10 (CoQ10) for the first time. CoQ10 was obtained from a fermentation broth extract. A non-aqueous two-phase solvent system composed of heptane – acetonitrile –dichloromethane (12:7:3.5) The separation yielded 130 mg of CoQ10 at an HPLC purity of over 99%. Crude extract CoQ10 purified by Si-gel CC CoQ10 purified by HSCCC HPLC purity (%) 89.2 96.0 99.2 Recovery (%)a – - 74.3 88.0 Yield (%)a – - 23.4 26.4 13. Separation of andrographolide and neoandrographolide from the leaves of Andrographis paniculata using HSCCC 14. Separation of WAP-8294A components, a novel anti-methicillinresistant Staphylococcus aureus antibiotic, using HSCCC 15. Large-scale separation of resveratrol,anthraglycoside A and anthraglycoside B from of,Polygonum cuspidatum by HSCCC Resveratrol is important as it has shown to have a cancer chemopreventive activity Two-phase solvent system composed of chloroform, methanol and water(4:3:2)

Advantages of CCC: 

Advantages of CCC 1. Quick 2. Inexpensive (only solvent costs, which is 5 times less than other LC technics) 3. Able to range from milligrams to tens of grams on the same instrument. 4. Able to switch between normal and reversed-phase. 5. Free of irreversible adsorption to a solid support (100% recovery of sample) 6. Increased capacity For the same volume of stationary phase, a CPC column gives a higher capacity than the HPLC one 7. No sample loss a simple rinsing of the instrument allows a full recovery of the non eluted fractions. 8. Easy maintenance No costly solid phase to change 9. No degradation / denaturation of compounds No interaction with silica - 10. No polarity restriction All biphasic mixture could be used

Advantages of HSCCC/CPC Technologies: 

Advantages of HSCCC/CPC Technologies HSCCC/CPC HPLC 1. No column 2. High recovery 3. High throughput 4. Retention of fragile Loss of biological activity Compounds (molecular integrity) 5. Volume ratio of stationary/mobile very high (better resolution) 1. Expensive columns 2. Irreversible adsorption 3. Poor loadability 4. Loss of biological activity (denaturation) 5. Ratio is low

Manufacturers of Countercurrent Instruments:: 

Manufacturers of Countercurrent Instruments: 1. AECS 2. Conway Centri Chrom 3. Dynamic Extractions 4. Pharma-Tech Research Corporation 5. Ever Seiko Corporation 6. Kromaton Technologies 7. Partus Technologies

Recent development in gas chromatography: 

Recent development in gas chromatography In addition to stationary phase and columns, the investigations are focused on comprehensive 2D GC, fast G.C & micro G.C. The performance of both columns & chromatographic equipment has been considerably improved . Packed columns are replaced by capillary columns with higher permeability. 1. Head space gas chromatography 2. Pyrolysis gas chromatography 3. High speed resolution capillary gas chromatography 4. Multidimensional chromatography comprehensive two dimensional chromatography Types:-

Basic Principles of Headspace Analysis: 

Basic Principles of Headspace Analysis “The 'headspace' is the gas space in a chromatography vial above the sample. Headspace analysis is therefore the analysis of the components present in that gas”. ‘Headspace GC is used for the analysis of volatiles and semi-volatile organics in solid, liquid and gas samples.’ The popularity of this technique has grown over recent years and has now gained world wide acceptance for analyses of alcohols in blood and residual solvents in pharmaceutical products . A headspace sample is normally prepared in a vial containing the sample, the dilution solvent, a matrix modifier and the headspace. Volatile components from complex sample mixtures can be extracted from non-volatile sample components and isolated in the headspace or gas portion of a sample vial.

PowerPoint Presentation: 

Phases of the Headspace Vial (G)= the gas phase (headspace) The gas phase is commonly referred to as the headspace and lies above the condensed sample phase. (S) = the sample phase The sample phase contains the compound(s) of interest. It is usually in the form of a liquid or solid in combination with a dilution solvent or a matrix modifier. Once the sample phase is introduced into the vial and the vial is sealed, volatile components diffuse into the gas phase until the headspace has reached a state of equilibrium as depicted by the arrows. The sample is then taken from the headspace Sample , dillution solvent, And matrix modifier Volatile analytes (G) (S)

Headspace Gas Chromatography Procedure: 

1) Place Sample in vial and seal it. 2) Place vial in Headspace Autosampler. 3) Collect Analysis results from data station - Automatic thermosetting to equilibrium for volatiles between the phases. - Automatic injection onto GC separation column of the gas-phase “extract”. Headspace Gas Chromatography Procedure

PowerPoint Presentation: 

Standby Pressure-Balanced Time-Based Sampling Carrier gas enters through Valve 1 (V1) and is directed partly through the heated transfer line to the GC and partly to the heated needle, which is constantly flushed to avoid cross contamination. The needle flush gas exits through the needle vent valve (V2). The following slides present the unique system of pressure balanced sampling, developed by PerkinElmer.

PowerPoint Presentation: 

Standby Pressurization Pressure-Balanced Time-Based Sampling Prior to injection, each vial is pressurized to a preset pressure with carrier gas to ensure that all injections are performed under the exact same conditions, regardless of different equilibrium pressures in different samples.

PowerPoint Presentation: 

Standby Pressurization Sampling Pressure-Balanced Time-Based Sampling During injection, the carrier gas supply and the needle purge are switched off. Sample flows to the separation/analysis system from the pressurized headspace vial. The injected volume is proportional to the injection time.

Pressure-Balanced Time-Based Sampling : 

Pressure-Balanced Time-Based Sampling Standby Pressurization Sampling Standby At the end of injection, the carrier gas and the needle purge are once more switched on and the injected sample volume driven through the analytical system. The needle is retracted and the system goes into standby mode.

Pyrolysis Gas chromatography : 

Pyrolysis Gas chromatography “In which the large molecules are degraded into small volatile species using only thermal energy”. The ultimate objective of analytical pyrolysis is to use the chromatographic information of pyrolysis products to determine the composition or structure of the original sample. Pyrolysis, combined with modern analytical methods , such as gas chromatography and/or mass spectrometry (Py-GC/MS) has become a quick, convenient and powerful tool for characterising polymers from involatile, complex heterogeneous samples.

Pyrolysis Gas chromatography technique : 

Pyrolysis Gas chromatography technique What is Pyrolysis GC? Pyrolysis is the breaking of chemical bonds through the use of thermal energy. Much like MS uses electron impact to fragment a compound into ions, pyrolysis uses heat to break the chemical bonds of a sample. Analytical pyrolysis uses this method of bond breaking as a means to analyze samples Pyrolysis GC is a method for the identification and structural analysis of samples Materials such as tire rubber, textiles, dried paint, glue, natural and synthetic polymers are unable to be analyzed by GC because of their high molecular weight and low volatility. Through the use of pyrolysis these compounds can be broken down into smaller, more volatile compounds to be analyzed using GC. Why Is Py -GC Needed?

Instrumental configuration : 

Instrumental configuration Pyrolysis device, or pyrolyzer, is interfaced with the analytical column of the GC via the injection port. The detection method used is typically mass spectrometry but other GC detectors have also been employed depending on the intentions of the analysis. Pyrolyzers Pyrolyzers: - capable of heating up to 1400ºC - operate between 500 and 800ºC for most analytical work - designed to connect directly to GC - three basic types (each with its own advantage and disadvantage) Types of Pyrolyzers include: 1. Microfurnace 2. Curie-Point Filament (Inductively Heated) 3. Resistively Heated Filament

1.Microfurance pyrolyzer :- : 

1.Microfurance pyrolyzer :- It rapidly raises the temperature of the sample until the pyrolysis temperature is reached and then maintains this temperature for the desired pyrolysis time. ‘The samples are either injected or dropped into the pyrolysis zone by liqui syringe, solid plunger syringe or by using a small cup.’ 2.Curie-Point Filament:- It accurately reproduce pyrolysis conditions using ferromagnetic metals. 3.Resistively Heated Filament:- It acquire a controlled pyrolysis temperature extremely quickly by using a piece of resistive metal.

Types of detector:- : 

Types of detector:- The purpose of a detector used in conjunction with pyrolysis-GC is to monitor the carrier gas as it leaves the column and respond to changes in its composition as solutes are eluted. 1.Mass Spectrometry- It is most widely used detector in qualitative and quantitative polymer analysis. 2.Flame ionization detector 3.Atomic emission detector 4.FTIR Advantages and Disadvantages Advantages Applicable technique for high molecular weight, nonvolatile organic constituents Composition identification and exploration of polymeric structures. Simple sample preparation Small sample size Disadvantages Small sample sizes can be non-representative Sample Loss High Initial cost

Application: : 

Application: 1.Biological samples:- Much work continues to be done in an effort to identify and differentiate biological materials such as microorganisms. 2.Environmental:- Application of these techniques in determining soil health status Analysis of the UV-B absorbing compounds in small numbers of pollen, spores and other microscopic entities was developed in order to allow research toward the effect of increased UV-B radiation on plants. 3.Food and agriculture:- Py -GC has ability to analyse complex molecules such as proteins, polysaccharides and lipids. Profiling of fatty acids in vegetable oils and animal fats

PowerPoint Presentation: 

Py -GC has developed considerably to become a routine tool for the identification and differentiation of synthetic polymers as well as the quantitative determination of monomers in copolymers. A great deal of research is now focused on the detection of low level chemical compounds in the polymers. A very recent study on the composition and microstructure of ethylene and propylene 6.Detection of additives and contaminants:- Additional research using Py -GC includes the study of both volatile and involatile organic compounds in extraterrestrial environments during planetary missions, and the examination of cuticles from fossil arthropods . Analysis of coal materials. The chemical structure, source(s), and formation pathway(s) of kerogen like organic matter in sediments from the northwestern Black Sea has also been investigated 4.Geochemistry and fuel sources 5.Symthetic polymers:-

Multidimensional Gas Chromatography and Comprehensive Two-Dimensional Gas Chromatography : 

Multidimensional Gas Chromatography and Comprehensive Two-Dimensional Gas Chromatography Overview: Comprehensive two-dimensional gas chromatography (GC×GC) is a technique that is ideally applied to the separation of complex mixtures of volatile and semi-volatile compounds. In a GC×GC separation, the sample is injected into a first chromatographic column (termed the primary column). Molecules elute from this column and are trapped or periodically sampled by a modulator (also termed an interface).

GC×GC Instrumentation:: 

GC×GC Instrumentation: The GC×GC instrument itself bears much similarity to a conventional GC Here, we high light the differences between conventional GC and GC×GC systems. due to the fact that most modulators compress and focus peaks into narrow bands, improving the signal The main advantages of the technique are vastly-expanded separation space and the ability to resolve hundreds or thousands of peaks ; improved sensitivity Advantages of GC×GC: This modulator periodically injects its contents onto a second column at a known, regular interval (typically in the range of 2-6 s). These fractions are very quickly separated on the second column and elute into a detector where they are measured.

PowerPoint Presentation: 

Nitrogen and sulphur chemiluminescence detectors (NCD and SCD), Time-of-flight mass spectrometer (TOFMS). Electron capture detector (ECD), Flame ionization detector (FID), Detectors: The other requirement is that the second column be short and have a diameter that is equal to or less than the first column. Typically the first column is non-polar and the second column is polar or semi-polar; however, combinations such as polar followed by non-polar have also been used with great success. Two columns must have different selectivities. Columns: The modulator is the interface between the two columns. It controls the flow of analytes from the first column to the second column, acting as a gate that performs these injections in a consistent and reproducible fashion. The heart on any GC×GC system is the modulator. Modulators:

Chiral Chromatography : 

Chiral Chromatography The living body is a highly chiral environment Biological activity of chiral substances often depends upon their stereochemistry. A large percentage of commercial and investigational pharmaceutical compounds are enantiomers , and many of them show significant enantioselective differences in their pharmacokinetics and pharmacodynamics. Introduction:- Chiral chromatography involves the separation of stereoisomers. Why Is chiral chromatography Needed? In the case of enantiomers, these have no chemical or physical differences apart from being three-dimensional mirror images. Conventional chromatography or other separation processes are incapable of separating them. To enable chiral separations to take place, either the mobile phase or the stationary phase must themselves be made chiral, giving differing affinities between the analytes.

PowerPoint Presentation: 

Chiral column chromatography is a variant of column chromatography in which the stationary phase contains a single enantiomer of a chiral compound rather than being achiral. Stationary $ mobile phase used in chiral chromatography Stationary phase containing an immobilized enantiomerically enriched selector molecule. Enantiomerically enriched selector molecule, added to the mobile phase .

PowerPoint Presentation: 

Chiral SFC vs. HPLC Advantages Reduced solvent Amounts (CO 2 reduces liquid waste) Reduced toxicity Solvent types (alkanes, chlorinated, etc) CO 2 has a net zero environmental impact Safety Reduce flammability Separation speed/efficiency Chiral Recognition: Ability of chiral stationary phase, CSP, to interact differently with each enantiomer to form transient-diastereomeric complexes; requires a interactions through: H-bonding π - π interactions Dipole stacking Inclusion complexing Steric bulk Five general types of cpc used in chromatography:- Polymer-based carbohydrates Pirkle or brush-type phases Cyclodextrins or cellulose type Chirobiotic phases Protein-based

Relationships of Stereoisomers : 

July 24-27, 2006, San Diego, CA Relationships of Stereoisomers Conformational isomers Courtesy of Brown/Foote, Organic Chemistry, 3/e, Figure 1 Harcourt, Inc. items and derived items copyright 2002 by Harcourt, Inc. and http://www.chem.uic.edu/web1/OCOL-II/WIN/STEREO/ISOMER.HTM Isomers: Compounds with the same molecular formula Constitutional (or structural) isomers Stereoisomers Same atom connectivity Different atom connectivity Interconvert through rotation about a single bond Conformational isomers or rotamers Configurational isomers Not readily Interconvertible Enantiomers Diastereomers Chiral w/ chiral centers (optically active) w/o chiral centers (opt. inactive) Geometric isomers Achiral Configurational isomers mirror images Enantiomers Cis, Trans (E,Z) isomers cis and trans isomers Constitutional (structural) isomers mirror images at this carbon Enantiomeric Not mirror images Diastereomers Not mirror images at this carbon Diastereomeric

PowerPoint Presentation: 

Latest development in HPLC Latest development is UPLC ( Ultra performance liquid chromatography). packing particle sizes (1.7µm) Higher pressures (15000psi) Allowed for significant increases in LC speed, reproducibility, and sensitivity. New research utilizing particle sizes as small as 1µm and pressures up to 100,000psi!

REFERENCE : 

REFERENCE http://mtsu32.mtsu.edu:11233/471toc.html (accessed 06/19/09). http://en.wikipedia.org/wiki/Chromatography (accessed 06/25/09). Robinson, J. W.; Skelly Frame, E.M.; Frame II, G.M. Undergraduate Instrumental Analysis, 6 th ed.; Marcel Dekker Inc.: NY, 2005; pp 797-835. http://www.chem.queensu.ca/courses/08/CHEM321/LectureNotes/Chapter%2025%20part%20one.doc (accessed 06/23/09). http://www.restek.com/info_sixport.asp (accessed 06/20/09). http://www.waters.com/waters/promotionDetail.htm?id=10048693&ev=10007792&locale=en_US (accessed 06/20/09). Dionex, Technical Note 75. “Easy Method Transfer from HPLC to RSLC with the Dionex Method Speed-Up Calculator” Levin, S.; Abu-Lafi, S. “The Role of Enantioselective Liquid Chromatography Separations Using Chiral Stationary Phases in Pharmaceutical Analysis” , in Advances in Chromatography. Grushka, E.; Brown, P. R., Ed.; Marcel Dekker Inc.: NY, 1993; Vol. 33; pp 233-236. Kline, P. “Analysis of Lactate Dehydrogenase: Determination of Molecular Weight and Purity”, Middle Tennessee State University, Murfreesboro, TN, 2009.

PowerPoint Presentation: 

(http://www.ccc4labprep.com/) (http://www.centrichrom.com/) (http://www.dynamicextractions.com/) (http://www.everseiko.co.jp) (http://www.kromaton.com/) (http://www.partus-technologies.com) Wampler, T.P., Introduction to pyrolysis-capillary gas chromatography, J. of Chromatogr. A, 1999, 842, 207-220. Wampler, T.P., Applied Pyrolysis Handbook, 2007. Sobeih, K.L., Baron, M., Gonzalez-Rodriguez, J., Recent trends and developments in pyrolysis-gas chromatography, J. of Chromatogr. A, 2008, 1186, 51-66. Rial-Otero, R., Galeiso, M., Capelo, J.L., Simal-Gandara, J., A Review of Synthetic Polymer Charachterization by Pyrolysis-GC-MS., Chromatographia., 2009, 70, 339-348. Wampler, T.P., Jansson, K.D., Zawodny, C.P., Analysis of Coatings, PCI Mag., 2009, 42-46.