• Prepare a Pasteur pipette by half-filling with Na 2 SO 4 (use glass wool as
stopper at top and bottom)
• After concentration to approx. 1 mL dry the n-pentane phase over the
Na 2 SO 4 filled pipette and collect the dried extract.
• Rinse the flask at least three times with n-pentane including drying over
Na 2 SO 4 . Collect the rinsed n-pentane and combine with the extract.
• Concentrate the combined n-pentane extract to a final analysis volume of
approx. 50 μL for further GC and GC/MS measurements.
Extraction step 2:
• Fill the pre-extracted water sample again into the separation funnel and add
50 mL of DCM.
• Shake the funnel for 5 min and vent it sporadically.
• Use a new flask to collect the DCM phase.
• Open the valve of the separating funnel and slowly separate the DCM
Phase. Close the valve before the water phase can enter the DCM phase
in the flask.
• If applicable add a surrogate internal standard.
• Dry and concentrate the DCM extract analogously to the pentane extract.
Extraction step 3:
• Lower the pH-value of the pre-extracted water sample to 2 by adding HCl.
• Treated the acidified water sample in the same way as the second extract.
Further handling:
Measure all individual extracts (extract 1: n-pentane; extract 2: DCM;
extract 3: DCM at pH2) separately by GC/MS or LC/MS
Standard Operation Procedure SOP 7—Solid Phase Extraction (SPE)
of Pollutants from Water Samples (River Water, Ground Water, Sewage
Effluents . . .)
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.
(continued)
7.2 Analyses of Environmental Samples
143
stopper at top and bottom)
• After concentration to approx. 1 mL dry the n-pentane phase over the
Na 2 SO 4 filled pipette and collect the dried extract.
• Rinse the flask at least three times with n-pentane including drying over
Na 2 SO 4 . Collect the rinsed n-pentane and combine with the extract.
• Concentrate the combined n-pentane extract to a final analysis volume of
approx. 50 μL for further GC and GC/MS measurements.
Extraction step 2:
• Fill the pre-extracted water sample again into the separation funnel and add
50 mL of DCM.
• Shake the funnel for 5 min and vent it sporadically.
• Use a new flask to collect the DCM phase.
• Open the valve of the separating funnel and slowly separate the DCM
Phase. Close the valve before the water phase can enter the DCM phase
in the flask.
• If applicable add a surrogate internal standard.
• Dry and concentrate the DCM extract analogously to the pentane extract.
Extraction step 3:
• Lower the pH-value of the pre-extracted water sample to 2 by adding HCl.
• Treated the acidified water sample in the same way as the second extract.
Further handling:
Measure all individual extracts (extract 1: n-pentane; extract 2: DCM;
extract 3: DCM at pH2) separately by GC/MS or LC/MS
Standard Operation Procedure SOP 7—Solid Phase Extraction (SPE)
of Pollutants from Water Samples (River Water, Ground Water, Sewage
Effluents . . .)
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.
(continued)
7.2 Analyses of Environmental Samples
143