3.2 Extraction
Outlook
The first main step in the analytical procedure of organic geochemical analyses
is the separation of organic analytes from the inorganic sample matrix. For this
purpose, dominantly extraction methods are applied to solid and liquid samples using different organic solvents as extractants. The principals as well as
the individual extraction techniques are introduced.
3.2.1 Principles of Extraction
The first important step in sample treatment is the isolation of the organic analytes
from the sample matrix and a simultaneous enrichment. For these purposes the
methods of extraction are the by far most common ones. These methods can be
roughly classified by the state of matter of both the sample as well as the extracting
agent or extractant (see Fig. 3.2). For sample material in organic geochemistry the
solid and the liquid state are the most important ones. As extractants liquids as well
as solid materials can be used. In combination, there exists one extraction system for
solids (sediments, rocks, soils, . . .) that consists of solid sample material and liquid
extraction solvents, shortly named solid/liquid extraction. For liquid sample material
(mainly water) two extractions systems exist: the liquid/liquid and the liquid/solid
extraction. Here, the application of solvents as extractants forming separate phases
(liquid/liquid) or solid adsorption materials (liquid/solid) are used.
All extraction processes are based on a partition process between the two phases.
After a certain time, this partition reaches a dynamic steady-state leading to constant
Liquid/liquid-extracƟon
Liquid/solid-extracƟon
Liquids
Solids
Solid/liquid-extracƟon
H 2 O
Solvent
H 2 O
Solvent
Fig. 3.2 Principal extraction systems
18
3 Sample Treatment
Outlook
The first main step in the analytical procedure of organic geochemical analyses
is the separation of organic analytes from the inorganic sample matrix. For this
purpose, dominantly extraction methods are applied to solid and liquid samples using different organic solvents as extractants. The principals as well as
the individual extraction techniques are introduced.
3.2.1 Principles of Extraction
The first important step in sample treatment is the isolation of the organic analytes
from the sample matrix and a simultaneous enrichment. For these purposes the
methods of extraction are the by far most common ones. These methods can be
roughly classified by the state of matter of both the sample as well as the extracting
agent or extractant (see Fig. 3.2). For sample material in organic geochemistry the
solid and the liquid state are the most important ones. As extractants liquids as well
as solid materials can be used. In combination, there exists one extraction system for
solids (sediments, rocks, soils, . . .) that consists of solid sample material and liquid
extraction solvents, shortly named solid/liquid extraction. For liquid sample material
(mainly water) two extractions systems exist: the liquid/liquid and the liquid/solid
extraction. Here, the application of solvents as extractants forming separate phases
(liquid/liquid) or solid adsorption materials (liquid/solid) are used.
All extraction processes are based on a partition process between the two phases.
After a certain time, this partition reaches a dynamic steady-state leading to constant
Liquid/liquid-extracƟon
Liquid/solid-extracƟon
Liquids
Solids
Solid/liquid-extracƟon
H 2 O
Solvent
H 2 O
Solvent
Fig. 3.2 Principal extraction systems
18
3 Sample Treatment