Gas Chromatography Introduction 1.) Gas Chromatography

Slides:



Advertisements
Similar presentations
Introduction to Chromatography
Advertisements

GAS CHROMATOGRAPHY CHAPTER 21.
Gas Chromatography 427 PHC.
Lecture 8b Gas Chromatography.
Gas Chromatography.
Gas Chromatography & Gas-Liquid Chromatography
GAS CHROMATOGRAPHY.
Mobile phase is a gas! Stationary phase could be anything but a gas
GC & LC.
HPLC 1. Introduction 1.Introduction CHROMATOGRAPHY Chromatography basically involves the separation of mixtures due to differences in the distribution.
1 1. Introduction H: High P : Performance (Pressure) L : Liquid C : Chromatography GC : Gas chromatography TLC: Thin layer chromatography IC : Ion chromatography.
4. Advances in Gas Chromatography. Topics covered capillary columns headspace analysis solid phase micro-extraction.
1 Gas Chromatography Lecture a. Thermal Conductivity Detector (TCD) This is a nondestructive detector which is used for the separation and collection.
The geometry of capillary columns is fairly simple, consisting of length, internal diameter, and stationary phase thickness. Nevertheless, there are endless.
Chem. 133 – 5/5 Lecture. Announcements Lab Report 2.4 due Thursday – can turn in today for reduction of late penalties Term Project Progress Report –
1 Chapter 24 GC Gas Chromatography. 2 GC Mechanism of separation is primarily volatility. Difference in boiling point, vapor pressure etc. What controls.
Intro to Chromatographic Separations Chap 26. Originally based on separation and identification by color Originally based on separation and identification.
Chromatography Chapter 4.
Chapter 22 GC & LC Gas Chromatography -1 1.Schematic diagram.
Pn. Suryati Bt. Syafri 2009 High Performance Liquid Chromatography (HPLC)
CHAPTER 29 Supercritical Fluid Chromatography The mobile phase is a supercritical fluid (a fluid above its critical T and critical pressure) Supercritical.
Effect of Packing Particle Size on Plate Height. Resolution between 2 adjacent peaks.
Principles of Chromatography. Chromatography is the most powerful tool for separating & measuring the components of a complex mixture. Quantitative &
LECTURE 4: CHROMATOGRAPHY Content: - Chromatographic separation - classifying analytical separations; column chromatography, planar chromatography - gas.
ANALYTICAL CHEMISTRY CHEM 3811 CHAPTER 21 DR. AUGUSTINE OFORI AGYEMAN Assistant professor of chemistry Department of natural sciences Clayton state university.
Chapter 22 GC & LC Gas Chromatography 1.Schematic diagram.
Chapter 6 - Chromatography
Chapter 27 Gas Chromatography 1. Principles
ANALYTICAL CHEMISTRY CHEM 3811 CHAPTER 22 DR. AUGUSTINE OFORI AGYEMAN Assistant professor of chemistry Department of natural sciences Clayton state university.
Chromatography Separates components in mixture: Based on - polarity
Chromatography Chapter 6.
Magnet Analytical Chemistry Unit 4
1.1 General description - Sample dissolved in and transported by a mobile phase - Some components in sample interact more strongly with stationary phase.
Separation Science Differences in IMFs can be used to separate chemical substances for further analysis. Differences in IMFs can be used to separate chemical.
Intro to Chromatography
PLOT Columns P orous L ayer O pen T ubular Porous layer open tubular (PLOT) columns are defined as capillary columns where the inner surface is coated.
animation.php.
INSTRUMENTAL ANALYSIS CHEM 4811 CHAPTER 12 DR. AUGUSTINE OFORI AGYEMAN Assistant professor of chemistry Department of natural sciences Clayton state university.
History of Chromatography n Early LC carried out in glass columns n diameters: 1-5 cm n lengths: cm n Size of solid stationary phase n diameters:
INTRODUCTION TO CHROMATOGRAPY
GAS CHROMATOGRAPHY (GC). GAS CHROMATOGRAPHY Sample is injected (using a syringe) into the injection port. Sample vaporizes and is forced into the column.
Gas Chromatography Lecture 38.
Gas Chromatography Experiment. Gas Chromatography - Gas Chromatography (GC) is a common technique used to separate and identify volatile organic compounds.
Intensive General Chemistry Chemical separations II Isabelle Vu Trieu
By: Arafath and Nick. What is it  Chromatography is a technique that is used to separate the substances present in a mixture.  It is widely used to.
Analytical Separations
Basic Gas Chromatography. History Separation of dyes by Runge Separation of plant pigments by Tswett Theoretical gc (Martin & Synge)
1 HPLC Lecture Displacement pumps Displacement pumps, on the other hand, is composed of a one directional motor driven plunger that pushes the mobile.
HPLC.
Chapter 28 High Performance Liquid Chromatography.
Ch 21 – Principles of Chromatography and Mass Spectrometry Ch 22 – Gas and Liquid Chromatography.
HPLC.
HPLC 1. Introduction 1.Introduction  INSTUMENTAL ANALYSIS  PRACTICAL 213 PHC  HPLC.
Chem. 133 – 5/3 Lecture. Announcements Lab – Term Project Progress Report Due Today – Last Assignments: Term Project Poster and Peer Review Grading (Friday,
Organic Analysis Basic concepts. Elements and Atoms Fundamental building block of all substances is the element. Fundamental building block of all substances.
Instrumental Analysis (I)  HPLC Tutorial #7 PHCMt561 – 5 th Sem. Pharm.
Lecture 9 Gas Chromatography Lecture 9 – Chromatography, Dr. Rasha Hanafi 1© Dr. Rasha Hanafi, GUC.
CHROMATOGRAPHY  A laboratory technique in which the components of a sample are separated based on how they distribute between two chemical or physical.
Experiments in Analytical Chemistry
1.1 General description - Sample dissolved in and transported by a mobile phase - Some components in sample interact more strongly with stationary phase.
Reading assignment: section 26E(p781) Chapter 26 # 2, 3, 14, 15, 16 Chapter 27 # 7(a,d,f), 22, 23, 24, 25.
Chem. 133 – 5/9 Lecture.
Overview Determining Identity Quantitative Analysis
Chem. 133 – 5/11 Lecture.
An Introduction to Chromatographic Separations
Satish Pradhan Dnyanasadhana College, Thane (W)
VAPOUR PHASE CHROMATOGRAPHY
Principle of separation of different components:
GAS CHROMATOGRAPHY.
High performance liquid chromatography (HPLC)
Presentation transcript:

Gas Chromatography Introduction 1.) Gas Chromatography Mobile phase (carrier gas) is a gas Usually N2, He, Ar and maybe H2 Mobile phase in liquid chromatography is a liquid Requires analyte to be either naturally volatile or can be converted to a volatile derivative GC useful in the separation of small organic and inorganic compounds Stationary phase: Gas-liquid partition chromatography – nonvolatile liquid bonded to solid support Gas-solid chromatography – underivatized solid particles Bonded phase gas chromatography – chemical layer chemically bonded to solid support Bonded phase Magnified Pores in activated carbon Zeolite molecular sieve

Gas Chromatography Introduction 2.) Instrumentation Process: Volatile liquid or gas injected through septum into heated port Sample rapidly evaporates and is pulled through the column with carrier gas Column is heated to provide sufficient vapor pressure to elute analytes Separated analytes flow through a heated detector for observation

Gas Chromatography Instrumentation 1.) Open Tubular Columns Commonly used in GC Higher resolution, shorter analysis time, and greater sensitivity Low sample capacity Increasing Resolution Narrow columns  Increase resolution Resolution is proportional to , where N increases directly with column length Easy to generate long (10s of meters) lengths of narrow columns to maximize resolution

Gas Chromatography Instrumentation 1.) Open Tubular Columns Increasing Resolution Decrease tube diameter Increase resolution Increase Column Length Increase resolution

Gas Chromatography Instrumentation 1.) Open Tubular Columns Increasing Resolution Increase Stationary Phase Thickness Increase resolution of early eluting compounds Also, increase in capacity factor and reduce peak tailing But also decreases stability of stationary phase

Gas Chromatography Instrumentation 2.) Choice of liquid stationary phase: Based on “like dissolves like” Nonpolar columns for nonpolar solutes Strongly polar columns for strongly polar compounds To reduce “bleeding” of stationary phase: bond (covalently attached) to silica Covalently cross-link to itself

Gas Chromatography Instrumentation 3.) Packed Columns Greater sample capacity Broader peaks, longer retention times and less resolution Improve resolution by using small, uniform particle sizes Open tubular column Packed column

500 L chromatography column Gas Chromatography Instrumentation 3.) Packed Columns The major advantage and use is for large-scale or preparative purification Industrial scale purification maybe in the kilogram or greater range 500 L chromatography column Oil refinery – separates fractions of oil for petroleum products

Gas Chromatography Retention Index 1.) Retention Time Order of elution is mainly determined by volatility Least volatile = most retained Polar compounds (ex: alcohols) are the least volatile and will be the most retained on the GC system Second factor is similarity in polarity between compound and stationary phase

Gas Chromatography Retention Index 2.) Describing Column Performance Can manipulate or adjust retention time by changing polarity of stationary phase Can use these retention time differences to classify or rate column performance Compare relative retention times between compounds and how they change between columns Can be used to identify unknowns

Gas Chromatography Temperature and Pressure Programming 1.) Improving Column Efficiency Temperature programming: Temperature is raised during the separation (gradient) increases solute vapor pressure and decrease retention time Temperature gradient improves resolution while also decreasing retention time

Gas Chromatography Temperature and Pressure Programming 1.) Improving Column Efficiency Pressure Programming: Increase pressure  increases flow of mobile phase (carrier gas) Increase flow  decrease retention time Pressure is rapidly reduced at the end of the run Time is not wasted waiting for the column to cool Useful for analytes that decompose at high temperatures Van Deemter curves indicate that column efficiency is related to flow rate Flow rate increases N2 < He < H2

Gas Chromatography Detectors 1.) Qualitative and Quantitative Analysis Compare retention times between reference sample and unknown Use multiple columns with different stationary phases Co-elute the known and unknown and measure changes in peak area The area of a peak is proportional to the quantity of that compound Peak Area Concentration of Standard Peak area increases proportional to concentration of standard if unknown/standard have the identical retention time  same compound