PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography A chromatograph is a computerized machine that analyzes hydrocarbons, chemicals, and permanent gases. A chromatograph is a computerized machine that analyzes hydrocarbons, chemicals, and permanent gases. During one analysis cycle a lot of components are separated and analyzed individually During one analysis cycle a lot of components are separated and analyzed individually The information from the chromatograph includes the mole percent or liquid volume percent of the components and/or parts per million of the components that make up the sample. The information from the chromatograph includes the mole percent or liquid volume percent of the components and/or parts per million of the components that make up the sample. The goal of an online process gas chromatograph is to supply quantitative and qualitative information. The goal of an online process gas chromatograph is to supply quantitative and qualitative information. The information is used to not only monitor and control the process but to optimize its use of energy, time and raw materials. The information is used to not only monitor and control the process but to optimize its use of energy, time and raw materials. PGC ( Process GC ) : Online but discontinous PGC ( Process GC ) : Online but discontinous

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Carrier Gas Carrier Regulator Sample Valve Column Detector Sample Conditioning Systems System Controller A basic Gas Chromatograph (GC) consists of the following parts:

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Sample Conditioning Systems  Sample probe  Sample Transport Tubing  Sample Phase Consistency  Filtration  Liquid Coalescing  Heat Tracing Speed Loops Automatic Stream switching  Calibration Standards  Multiple Sample Streams

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography A basic Gas Chromatograph (GC) consists of the following parts:  Carrier Gas Carrier Gas Carrier Regulator Sample In Sample out SV Column Sense Ref. Atmos Vents Carries the sample through the column and detector to an atmospheric vent.

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography A basic Gas Chromatograph (GC) consists of the following parts:  Carrier Regulator Carrier Gas Carrier Regulator Sample In Sample out SV Column Sense Ref. Atmos Vents Maintains a constant pressure of carrier gas which results in a constant carrier flow rate.

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography A basic Gas Chromatograph (GC) consists of the following parts:  Sample Valve Carrier Gas Carrier Regulator Sample In Sample out SV Column Sense Ref. Atmos Vents Injects a measured amount of sample.

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography A basic Gas Chromatograph (GC) consists of the following parts:  Column Carrier Gas Carrier Regulator Sample In Sample out SV Column Sense Ref. Atmos Vents Separates the sample into individual components.

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography A basic Gas Chromatograph (GC) consists of the following parts:  Detector Carrier Gas Carrier Regulator Sample In Sample out SV Column Sense Ref. Atmos Vents Senses the individual components as they elute off the column.

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Gas Chromatogram:  The trace of the detector signal drawn on a recorder. SV1 G1 G2 G3 G4 G2 G3 G4 SV1 SSO BAL Reset SSO CV1

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Peak area is directly proportional to the concentration of the component. Peak Area / Response Factor = Concentration of the Component Retention time for each component is always the same. Retention time is the time from sample inject to the top of the peak. Two Important laws in chromatography

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Retention time:

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Change in carrier flow rate. Change in oven temperature Degrading columns Three things that can cause the retention time of the peak to change.

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography A basic Gas Chromatograph (GC) consists of the following parts:  Column Carrier Gas Carrier Regulator Sample In Sample out SV Column Sense Ref. Atmos Vents

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Separation on column

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Types of columns

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Packed Column Material Liquid Coating Support

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Packed Column - Principal operation

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography A basic Gas Chromatograph (GC) consists of the following parts:  Column Hydrocarbon Path through column Column To detector

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Non-Polar columns This coating is usually some type of oil. These liquid phases separate components by boiling points. C1 -Methane C2-Ethane C3-Propane IC4-Iso-butane NC4-Normal Butane IC5-Iso-pentane NC5-Normal pentane C6+-Hexane and heavier

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Polar Columns A liquid coating that acts much like a magnet. The more polar the column the longer the components stay in the column.

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Adsorption Columns These columns separate permanent gases and light hydrocarbons by molecular size.

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Basic Chromatography Capillary Column Material Glass Column Liquid Coating

PAS-Intro1 Dated 24th Aug Copyright © Siemens AG 1999 All Rights Reserved Siemens Advanced Engineering Pte Ltd Process Analytical Services Division Advantages: –lower temperatures –faster –more inert –better separation –longer life –lower carrier gas consumption –more stable at higher temperatures Capillary Columns Basic Chromatography