especially those with low centration levels such as ground and river water, do not
need a fractionation step, whereas many solid samples are relatively rich in organic
matter needing a fractionation prior to GC/MS and LC/MS analyses. In order to
improve the extraction efficiency, sequential extraction procedures are applied for
water samples, whereas for solid samples repetitional extraction steps with solvents
of varying polarity can be used.
In the following some standard operation procedures for extraction and fractionation of environmental samples are listed. They derive from the authors laboratories.
Please note that standard operation procedures presented above for extraction of
solid fossil material (ASE, Soxhlet, ultrasonication) are also applicable for solid
environmental samples such as soils, suspended particulate matter or river
sediments.
Standard Operation Procedure SOP 6—Sequential Liquid/Liquid
Extraction of Pollutants from River Water Samples
Preconditions:
• Clean all needed material by rinsing with purified acetone and n-hexane and
make sure to use only glass, metal and PTFE equipment.
• For the analytical procedure precleaned (distilled) or ultra-pure solvents
should be used.
Extraction step1:
• Filter 1 L aliquots of the water sample using a glass fibre filter with 0.45 μm
pore size.
• Transfer the sample into a 1 L separating funnel.
• If applicable add an internal standard.
• Add 50 mL of purified n-pentane to the sample for the first extraction step.
• Close the separating funnel with a matching stopper and shake it intensively
for 5 min. Make sure to regularly vent the funnel through the faucet in
particular at the beginning of the shaking procedure in order to avoid
overpressure.
• Allow to stand for 30 min so that the phases can separate properly.
• Use a 1 L bottle to collect the water phase underneath the funnel. Slowly
open the valve and close it right before the n-pentane phase enters the
bottle.
• Decant the n-pentane phase through the top opening of the funnel into a
small flask.
• Open the valve of the funnel and dry it with approximately 1 pipette of
acetone.
• If applicable add a surrogate standard to the n-pentane phase.
• Concentrate the organic extract by rotary evaporation.
(continued)
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7 Principal Analytical Procedures in Organic Geochemistry
need a fractionation step, whereas many solid samples are relatively rich in organic
matter needing a fractionation prior to GC/MS and LC/MS analyses. In order to
improve the extraction efficiency, sequential extraction procedures are applied for
water samples, whereas for solid samples repetitional extraction steps with solvents
of varying polarity can be used.
In the following some standard operation procedures for extraction and fractionation of environmental samples are listed. They derive from the authors laboratories.
Please note that standard operation procedures presented above for extraction of
solid fossil material (ASE, Soxhlet, ultrasonication) are also applicable for solid
environmental samples such as soils, suspended particulate matter or river
sediments.
Standard Operation Procedure SOP 6—Sequential Liquid/Liquid
Extraction of Pollutants from River Water Samples
Preconditions:
• Clean all needed material by rinsing with purified acetone and n-hexane and
make sure to use only glass, metal and PTFE equipment.
• For the analytical procedure precleaned (distilled) or ultra-pure solvents
should be used.
Extraction step1:
• Filter 1 L aliquots of the water sample using a glass fibre filter with 0.45 μm
pore size.
• Transfer the sample into a 1 L separating funnel.
• If applicable add an internal standard.
• Add 50 mL of purified n-pentane to the sample for the first extraction step.
• Close the separating funnel with a matching stopper and shake it intensively
for 5 min. Make sure to regularly vent the funnel through the faucet in
particular at the beginning of the shaking procedure in order to avoid
overpressure.
• Allow to stand for 30 min so that the phases can separate properly.
• Use a 1 L bottle to collect the water phase underneath the funnel. Slowly
open the valve and close it right before the n-pentane phase enters the
bottle.
• Decant the n-pentane phase through the top opening of the funnel into a
small flask.
• Open the valve of the funnel and dry it with approximately 1 pipette of
acetone.
• If applicable add a surrogate standard to the n-pentane phase.
• Concentrate the organic extract by rotary evaporation.
(continued)
142
7 Principal Analytical Procedures in Organic Geochemistry