BS/EN 15308-2016 pdf download.Characterization of waste Determination of selected polychlorinated biphenyls (PCB) in solid waste by gas chromatography with electron capture or mass spectrometric detection.
Perform a blank determination following the paragraphs of the procedure applied to samples (selected extraction and clean-up). Use the same amounts of reagents that are used for pretreatment, extraction, clean up and analysis of samples. Analyse the blank immediately prior to analysis of the samples to demonstrate freedom from contamination.
11.2 Extraction
11.2.1 Extraction by shaking or sonification
Weigh a test portion of lOg to 25 g to the nearest 0.1 gin a stoppered flask. Add a definite volume of the internal standard solution. Isotopically labelled internal standards may be added after extraction to an aliquot of the extract where appropriate. Typically the concentration of the individual internal standards In the final extract will be 0,1 pg/mI. Add 50 ml of acetone to the test sample. Extract by shaking thoroughly for 30 mm on a shaking device or by sonification. Then add 50 ml of hexane-like solvent (5.2.2) and extract again thoroughly during 30 mm. After the solids have settled decant the supernatant. Wash the remaining solids with SO ml of hexane-like solvent (5.2.2) and decant again. Collect the extracts in a separatory funnel and remove the acetone by shaking twice with 400 ml of water. Dry the extract over anhydrous sodium sulfate. Filtrate or decant the extract and rinse the sodium sulfate three times with 10 ml of hexane-like solvent (5.2.2) and add the rinsings to the extract. Reduce the volume of the extract according to the applied clean-up procedure.
In case of waste material with a high proportion of plastic, e.g. plastic shredder, extraction with an acetone containing solvent leads to a high amount of co-extractives. In these cases, extraction should be performed twice with 50 ml of hexane-like solvent (5.2.2).
11.2.2 Soxhlet extraction
Weigh a test portion of lOg to 25 g to the nearest 0,1 g in the extraction thimble. Add a definite volume of the internal standard solution. Isotopically labelled internal standards may be added after extraction to an aliquot of the extract where appropriate. Typically the concentration of the individual internal standards in the final extract will be 0,1 pg/mI. Add approximately 70 ml of the extraction mixture acetone/hexane-like solvent (5.2.1/5.2.2) 1:1 to the extraction vessel. Extract the sample for a minimum of 100 extraction cycles. Transfer the extract in a separatory funnel and remove the acetone by shaking twice with 400 ml of water. Dry the extract over anhydrous sodium sulfate. Filtrate or decant the extract and rinse the sodium sulfate three times with 10 ml of hexane-like solvent (5.2.2) and add the rinsings to the extract. Reduce the volume of the extract according to the applied clean-up procedure.
In case of waste material with a high proportion of plastic, e.g. plastic shredder, extraction with an acetone containing solvent leads to a high amount of co-extractives. In these cases, extraction should be performed with 50 ml olbexane-like solvent (5.2.2).
11.3.1 General
Clean-up of extracts shall be conducted if compounds are expected to be present that can interfere with the PCB congeners of interest In the gas chromatogram or if those compounds can influence the GCprocedure (i.e. contamination of the detection system). If no or negligible interfering substances are present, no clean-up is necessary. Before applying the clean-up to real samples the laboratory shall ensure that recoveries of all relevant congeners including internal standards are at least 70 %. If polar compounds have to be removed take special care on the recoveries of the low chlorinated PCB. A suitable injection standard shall be added to the final extract before GC-ECD or GC-MS analysis after the final clean-up and concentration to the desired volume have been performed.
11.3.2 Aluminium oxide clean-up
Prepare a chromatography column by placing a small plug of quartz wool (6.1.3.1) in the chromatography tube (6.1.3.4) and adding 2,0 g ± 0,1 g of aluminium oxide (5.3.1.1).
Apply the extract to the dry packed column; rinse the sample vessel twice with 1 ml of hexane-like solvent (5.2.2). Add the rinses to the column as soon as the liquid level has reached the surface of the column packing. Elute with approximately 20 ml of hexane-like solvent (5.2.2). Collect the entire eluate. Concentrate to the desired volume. If a new batch of aluminium oxide is used the solvent volume to elute the specified PCB congeners completely from the column shall be determined using a proper PCB standard solution
Commercially available disposable aluminium oxide cartridges may be used as an alternative if found equally suitable.
11.3.3 Silica cartridge clean-up
Pre-wash the silica cartridges (5.3.4) with n-hexane like solvent (5.2.2). Do not allow the cartridges to become dry. When the solvent is within 1 mm of the packing apply an aliquot of 1 ml of the sample extract (11.2) to the column. Elute the PCB with n-hexane like solvent (5.2.2) at 1 mI/mm (approximately 5 ml of n-hexane like solvent (5.2.2) are required for complete elution of the P03 congeners of interest when using a cartridge with 3 ml capacity). Collect the entire eluate. Concentrate to the desired volume.
11.3.4 Silica H2S04 clean-up
Prepare a chromatography column by pouring consecutively I g of silica NaOH (5.3.8.2), 5 g of silica HSO4 (5.3.8.1) and 2 g of anhydrous Na2SO4 (5.2.3) in a clean chromatography column. Add a sufficient amount of n-hexane and elute until the top of the n-hexane like solvent (5.2.2) phase reaches the top of the Na2SO4 layer. Place with the aid of a Pasteur pipette the extract on top of the Na2SO4 layer and make it penetrate into the Na2SO4 layer. Elute with ca 60 ml of n-hexane like solvent (5.2.2) and collect the entire n-hexane like solvent (5.2.2) fraction. Concentrate to the desired volume.BS/EN 15308-2016 pdf download.