One Step Extraction, Clean Up and Direct-to-vial Concentration for PCBs in Soil and Sediment
Oral Presentation
Prepared by R. Addink
Toxic Report, 580 Pleasant Street 2nd Floor, Watertown, MA, 02472, United States
Contact Information: [email protected]; 617-393-1713
ABSTRACT
Polychlorinated biphenyls (PCBs) are a class of 209 toxic chemical compounds that were used as dielectric fluids in capacitors, coolants and transformers. They were gradually phased out worldwide in the 1970s. They are part of the 2001 Stockholm Convention on Persistent Organic Pollutants. Since they are chemically inert and resist environmental degradation they tend to accumulate in soil and river sediment. Method 8082 is used to analyze PCBs in extracts from liquids and solids using GC-ECD. A new application speeds up these analyses using integrated Pressurize Liquid Extraction (PLE) with subsequent clean up in a single step.
The PLE is typically done at 120 oC and 1500 psi for about 15-30 min. Extraction takes place in a stainless steel extraction cell filled with a mixture of sample and inert material (Hydromatrix™). The cell has an InCell Acid Silica end cap through which the sample passes at the end of the extraction cycle, providing integrated clean up after the extraction. Separate column chromatography is therefore not necessary. After passing through the silica containing cap the samples are discharged into an evaporator and reduced in volume with nitrogen. The evaporator tubes used have direct-to-vial connections so that no sample transfer is necessary. After volume reduction the sample is ready for GC-ECD or GC-MS analysis.
Sand and sediment were spiked with 100 ppb of 19 PCB congeners (mono-chloro- through nona-chloro-) and extracted with this system. PCB-209 was used as internal standard. Native recoveries were 100-144% for sand and 75-97% for sediment.
Oral Presentation
Prepared by R. Addink
Toxic Report, 580 Pleasant Street 2nd Floor, Watertown, MA, 02472, United States
Contact Information: [email protected]; 617-393-1713
ABSTRACT
Polychlorinated biphenyls (PCBs) are a class of 209 toxic chemical compounds that were used as dielectric fluids in capacitors, coolants and transformers. They were gradually phased out worldwide in the 1970s. They are part of the 2001 Stockholm Convention on Persistent Organic Pollutants. Since they are chemically inert and resist environmental degradation they tend to accumulate in soil and river sediment. Method 8082 is used to analyze PCBs in extracts from liquids and solids using GC-ECD. A new application speeds up these analyses using integrated Pressurize Liquid Extraction (PLE) with subsequent clean up in a single step.
The PLE is typically done at 120 oC and 1500 psi for about 15-30 min. Extraction takes place in a stainless steel extraction cell filled with a mixture of sample and inert material (Hydromatrix™). The cell has an InCell Acid Silica end cap through which the sample passes at the end of the extraction cycle, providing integrated clean up after the extraction. Separate column chromatography is therefore not necessary. After passing through the silica containing cap the samples are discharged into an evaporator and reduced in volume with nitrogen. The evaporator tubes used have direct-to-vial connections so that no sample transfer is necessary. After volume reduction the sample is ready for GC-ECD or GC-MS analysis.
Sand and sediment were spiked with 100 ppb of 19 PCB congeners (mono-chloro- through nona-chloro-) and extracted with this system. PCB-209 was used as internal standard. Native recoveries were 100-144% for sand and 75-97% for sediment.
