ISO 17993:2002 pdf download

ISO 17993:2002 pdf download.Water quality -Determination of 15
polycyclic aromatic hydrocarbons (PAH) inwater by HPLC with fluorescence detection after liquid-liquid extraction.
5.6 Molecular sieve beads, having a pore diameter of 0,4 nm and having been completely activated.
5.7 Reference compounds, listed in Table 1.
Because of the dangerous nature of these compounds, it is highly recommended to use commercially available, preferably certified, standard solutions. Avoid skin contact.
5.8 Stock solutions.
The solutions 5.8.1 and 5.8.2 are stable for at least a year when stored in the dark at room temperature and protected from evaporation.
5.8.1 Single compound stock solutions, of those listed in Table 1, diluted in acetonitrile (5.1.3) to a mass concentration of, for example, 10 pg/mI.
These solutions are used for confirmation and identification of single PAH in the chromatogram.
5.8.2 Multiple compound stock solution, certified, diluted in acetonitrile (5.1.3) to a mass concentration of, for example, 10 pg/mI for each individual compound.
5.9 Reference solutions.
Prepare at least five calibration solutions by appropriate dilution of the stock solution (5.8.2), using methanol (5.1.3) or acetonitrile (5.1.3) as the solvent. The choice of the solvent depends on the composition of the HPLC mobile phase.
Transfer, for example, 50 p1 of the stock solution into a 5 ml volumetric flask and make up to the mark with acetonitrile. One microlitre of this reference solution contains 100 pg of the respective individual compounds.
These solutions remain stable for at least a year when stored in the dark at room temperature and protected from evaporation. To ensure their stability, run a quality control check regularly on the reference solutions.
Checking the mass concentration of the PAH in the stock solution is only possible by comparison with an independent, preferably certified, standard solution.
6 Apparatus
Standard laboratory glassware cleaned to eliminate all interferences. All glassware can be cleaned, for example by rinsing with detergent and hot water, and drying for about 15 mm to 30 mm at about 120 °C. After cooling, rinse with acetone, seal the glassware and store in a clean environment.
Do not use glassware that has been in contact with wastewater samples or samples with high PAH concentrations for drinking water analysis.
6.1 Brown glass bottles, narrow-necked, flat-bottomed, 1 000 ml, with glass stopper, preferably of known mass.
6.2 Magnetic stirrer, with stirring bars, glass or polytetrafluoroethene (PTFE) coated, for stirring the solvent used for extraction.
6.3 Separating funnel, of 1 000 ml capacity, with PTFE stopcock and glass stopper.
6.4 Conical flasks, of 100 ml and 250 ml capacity, with glass stopper.
6.5 Microlitre syringes, of 500 p1 and 1 000 p1 capacity.
6.6 Reduction flask, of 100 ml capacity (see Figure B.1).
6.7 Centrifuge with rotor, for centrifuge tubes with tapered bottoms of 50 ml capacity (see Figure B.2).
6.8 Pasteur pipettes.
6.9 Evaporation assembly, for example a rotary evaporator with a vacuum stabilizer and a water bath.
6.10 Shaking apparatus, with adjustable rotational speed.
6.11 Microfilter, with a solvent-resistant hydrophilic membrane and a pore size of 0,45 pm.
6.12 Glass autosampler vials, of approximately 2 ml capacity, with an inert cap, e.g. PTFE coated septum.
6.13 Polypropene or glass cartridges, filled with at least 0,5 g of silica (see 5.5).
NOTE These cartridges are commercially available.
6.14 Glass vials, e.g. centrifuge tubes, graduated (scale division 0,1 ml), nominal capacity 10 ml, with glass stoppers.
6.15 High performance liquid chromatograph (HPLC), with fluorescence detector and data evaluation system, including:
6.15.1 Degassing assembly, e.g. for degassing with vacuum or helium.
6.15.2 Analytical pumps, capable of binary gradient elution.
6.15.3 Column thermostat, capable of keeping the temperature constant to within ± 0,5 °C.
6.15.4 Fluorescence detector, capable of programming at least six pairs of wavelengths, including damping/amplification, preferably equipped with monochromator(s).
6.16 Analytical separation column, meeting the separation requirements given in 8.5.2 (for examples see annex A).
7 Sampling
When sampling drinking water from a tap of the water supply, collect the test sample before the tap is sterilized for bacteriological sampling.
Collect the test sample in a brown glass bottle (6.1). Dechlorinate water test samples containing chlorine by immediately adding approximately 50 mg of sodium thiosulfate (5.2).
Fill the bottle to the shoulder (approximately 1 000 ml) and store the test sample at about + 4 °C and protect it from light until the extraction is carried out. Ensure that the extraction is carried out within 24 h after sampling in order to avoid losses due to adsorption. When the complete analysis cannot be performed within 24 h, perform the following procedure within this time limit. Remove a part of the sample from the sampling bottle until a sample volume of about 1 000 ml ± 10 ml remains and determine the volume of the test sample by weighing the bottle, add 25 ml of hexane (5.1.2) and shake well. The pretreated test sample may be stored for 72 h at about + 4 °C, protected from light.