EN ISO 16703:2011 pdf free.Soil quality – Determination of content of hydrocarbon in the range C10 to C40 by gas chromatography.
7 Apparatus
7.1 Standard laboratory glassware, which shall be treated at high temperatures or rinsed with acetone (6.1) and dried before use.
7.2 Mixing device.
A mechanical shaker with at least 120 horizontal shaking movements per minute, or alternatively an ultrasonic bath, can be used.
7.3 Laboratory centrifuge, capable of producing an acceleration of at least 1 500 g.
7.4 Gas chromatograph, equipped with a non-discriminating injection system [preferably on-column or programmable-temperature vaporization injection (PTV)J. a capillary column and a flame ionization detector
NOTE The use of a large-volume infection system can improve the limit of detection consderab1y.
7.5 Capillary column, of fused silica, with the following properties:
—non-polar stationary phase: e.g. immobilized 100 % dimethyl polysiloxane, 95 %-dimethyl-5 %- diphenyl polysiloxane. or modified siloxane polymer;
—length: lOmto25m:
—internal diameter: 0,1 mm to 0.32 mm:
— film thickness: 0.1 pm to 1,0 pm.
The column shall give a baseline separation for the n-alkanes in the system-performance standard solution (6.9).
Thermally stable low-bleed columns are preferred.
The use of a pre-column, e.g. wide-bore (0,53 mm internal diameter) deactivated fused silica of at least 2 m of length that suits the analytical column and Is connected to it using a zero-volume connector, is recommended.
7.6 Data system, capable of integrating the total area of the chromatogram, compensating for column bleed and reintegrating after defining a new baseline.
7.7 Glass extraction vessel, of volume at least 100 ml, with screw caps provided with an inlay of PTFE.
7.8 Glass tube, of volume 25 ml, with a ground-glass stopper or with screw caps provided with an inlay of
7.9 Separatory funnel, of capacity at least 500 ml. with a ground-glass stopper.
7.10 Chromatography column for clean-up.
Glass columns of about 10 mm internal diameter shall be used. The upper part of the column should be widened to use as a solvent reservoir and the lower part narrowed to form a tip.
8 Sampling, sample conservation and pretreatment
Sampling shall be carried out according to ISO 10381-1 and in coordination with the analytical laboratory.
The samples should be kept sealed in darkness at a temperature of about 4 °C, and extracted within a period of 1 week.
If this is not possible, samples shall be stored at -18 °C or lower. Before analysis the samples shall be homogenized.
9 Procedure
9.1 Preparation of the clean-up column
Push a plug of pre-washed glass wool or a PTFE frit down into the column (7.10), Then, successively add 2 g
of Flonsil (63) and 2 g of sodium sulfate (6.4). Prepare the column immediately before use.
9.2 Blank
With each sefles of samples, carry out a blank determination according to 9.3 using all reagents in identical amounts but without a sample, If blank values are unusually high (more than 10 % of the lowest value of interest), every step in the procedure shall be checked to determine the cause of these high blanks.
9.3 Extraction and clean-up
Weigh an exact amount (about 20g) of the homogenized field-moist or pretreated soil sample according to Iso 14507 into a glass extraction vessel (7.7) and add (40 ± 1) ml of acetone (6.1). After briefly shaking by hand, add (20 ±0,1) ml of the RTW-standard solution (6.6). Close the vessel and extract the sample for 1 h using mechanical shaking or sonication (7.2). After settling of the solid material, transfer as much as possible of the supernatant into a separatory funnel (7.9). To remove the acetone, wash the organic phase twice by shaking thoroughly (5 mm) with 100 ml of water. Collect the organic layer in a glass tube (7.8). Add sufficient sodium sulfate so that no lumps are formed. Transfer 10 ml of the extract to a clean-up column filled with Florisil (9.1). Do not pre-wash the column with organic solveni Collect the entire eluate. Transfer an aliquot of the purified extract to a GC-vial and analyse by gas chromatography.
If appropriate, test portions of 5 g to 30 g can be used (e.g. smaller test portions should be used if samples adsorb the major portion of the extraction solvent added: sample intake should be increased if high sensitivity is required).
Alternative extraction procedures, e.g. accelerated solvent extraction (ASE), may be used provided they give comparable extraction performances.
It is very important that the clean-up column be freshly prepared and active, and that the extract be tree of acetone [less than 0,1 % (volume fraction)I, especially when the sample contains polycyclic aromatic hydrocarbons (PAH) in addition to mineral oil hydrocarbons. Make sure that PAHs are adsorbed on the cleanup column. If the distinct peaks of PAHs are observed in the GC-FID chroniatogram (see Annex A), this should be mentioned in the test report.
NOTE To implove and accelerate phase separation, centrifugaban can be applied povided that the necessary safely precautions, especially with regard to flammable solvents, are taken into account.EN ISO 16703 pdf download.