BS ISO 22032:2006 pdf download – Water quality — Determination of selected polybrominated diphenyl ethers in sediment and sewage sludge — Method using extraction and gas chromatography/mass spectrometry
Use commercially available solutions (may be in nonane, toluene or iso-octane) or prepare stock solutions,e.g. by dissolving 10 mg of each of the reference substances (5.2,5.3) in toluene (5.1) in an amber,10-mlvolumetric flask and bring to volume (concentration: 1 mg/ml). Store at approximately-18 °C in the dark.
5.8Multicomponent stock solution of reference substances.
Accurately transfer between 100 ul to 500 pl of each single standard solution (5.7) into an amber,10-mlvolumetric flask and bring to volume with the appropriate solvent, e.g. toluene, or nonane, or iso-octane (5.1).(Concentrations are between 10 ug/ml and 50 ug/ml per substance.)
5.9Calibration solutions for multicomponent-multilevel calibration.
Prepare,e.g. seven calibration solutions with concentrations according to the detection capacity of the massspectrometer. Combine the multicomponent stock solutions of reference substances (5.8), internal standards(5.10) and,if necessary,injection standard (5.12) to produce the solutions (e.g. shown in Table 5) byappropriate dilution with the appropriate solvent, e.g. toluene, or nonane, or iso-octane (5.1).
In order to avoid potential photodegradation, store the solutions in the dark. Check the concentrations ofcalibration solutions before use.
Use one of the calibration solutions to optimize the GC-MS system and to determine the retention times. Asan alternative, determine and use relative retention times.
5.10 Stock solution of the internal standards.
Prepare a stock solution of the internal standards at an appropriate concentration in, e.g. toluene or iso-octane(2,2,4-trimethylpentane). Dilute this stock solution. See ‘Table 5 for suggested concentrations of calibrationsolutions and sample extracts.
5.11Clean-up material.
See Annex A.
5.12 Injection standard.
Use an injection standard,e.g. dibromooctafluorobiphenyl (C12BrzFg). to determine recovery rates for theinternal standard in each sample.
5.13 Baked sand.
Bake sand for at least 8 h at 400 °℃.
6 Apparatus
Clean all glassware by rinsing with acetone (propanone)(5.1).Heating the glassware to 400 C will reduceblanks. Recalibrate volumetric apparatus prior to use if heated.
6.1Wide-necked bottle, 1 000 ml up to 5 000 ml capacity,for wet sediment or sludge.6.2Freeze drying apparatus.
6.3Deep freezer.
6.4 Mortar and pestle, or a grinding mill.
6.5Drying ovens, capable of maintaining temperatures in the ranges of 100 °C to 400 °C for baking andstorage of clean-up materials, for baking of glassware and for dry residue determination of samples.
6.6Sieve shaker with appropriate sieve meshes (aperture size), e.g. 2 mm.
6.8Soxhlet extraction apparatus, consisting of round bottom flasks (e.g. 250 ml),Soxhlet extractors andSoxhlet thimbles (e.g.27 mm x 100 mm), vertical condensers (e.g.300 mm) and heating apparatus.
6.9 Evaporation device, e.g. rotary evaporator, turbo evaporator or vacuum concentration device.
6.10 Glass columns for chromatographic clean-up.
6.11 volumetric cylinders, 250 ml and 500 ml.6.12 Volumetric flasks,1 ml, 2 ml, 10 ml, and 25 ml.
6.13 Pasteur pipettes,e.g. 2 ml.
6.14 Syringes, 2 ul.5 ul,10 ul and 50 ul,volume precision± 2 %.6.15 Sample vials.
Amber glass with fluoropolymer-lined screw-cap is most suitable.
6.16 Gas chromatograph, with either a sp)litless injection port or an on-column injection port coupled to amass spectrometer (Gc-MS) with electron impact or chemical ionization and appropriate reactant gas(e.g.CH4).
6.17Analytical column.
Fused silica column with non-polar low bleed separating phase (see Annex B for examples), e.g. innerdiameter <0,25 mm, length 15 m to at maximum 30 m (shorter columns for higher brominated congeners).A film thickness of 0,1 um is recommended.
7 Sampling and sample pre-treatment
Take samples as specified in IS0 5667-13 in a bottle (6.1).Store and transport in the dark at approximately4 ℃.Pre-treat the samples immediately in the laboratory by homogenizing and freeze-drying.Grind thesamples using apparatus(6.4) and sieve them using a sieve shaker (6.6) according to the analytical task.
8 Procedure
8.1 Extraction Transfer a suitable mass, e.g. 5 g to 10 g, of the pre-treated, dry sample into a Soxhlet thimble. Depending on the expected concentration in the sample, add 100 µl to 1 000 µl of the internal standard solution (5.10), to the Soxhlet thimble. Place the thimble in the Soxhlet extractor. The various solvents given in 5.1 produce similar extraction efficiencies after a 16 h Soxhlet extraction. Certain sample matrices may require a more polar solvent to efficiently extract the PDBE congeners, e.g. a mixture of acetone (propanone) and hexane, or dichloromethane.