ISO 17993 pdf download – Water quality -Determination of 15 polycyclic aromatic hydrocarbons (PAH) inwater by HPLC with fluorescence detection after liquid-liquid extraction

ISO 17993 pdf download – Water quality -Determination of 15 polycyclic aromatic hydrocarbons (PAH) inwater by HPLC with fluorescence detection after liquid-liquid extraction.
5.8 Stock solutions.
The solutions 58.1 and 5.8.2 are stable for at least a year when stored m the dark at room temperature and protected from evaporation.
5.8.1 Single compound stock solutions, of those listed in Table 1, dduted 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 MultIpl, compound stock solution, certified, diluted In acetonltrile (5.1.3) to a mass concentration of, for example, 10 pglml for each md.vldual compound.
5.9 Reference solutions.
Prepare at least five calibation solutions by appropnate dilution of the stock solution (5.82), 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 aoetonitrile. 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 poss4ble by comparison with an independent, preferably certified, standard solution.
6 Apparatus
Standard laboratory glassware cleaned to elimriate 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 coding, 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 dnnking 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).
6.15.4 Fluorescence detector, capable of programmrig at least six pairs of wavelengths. rdudlng damplnglampllftcabon, preferably equipped with monoctiromator(s).
6.16 Analytical separation column, meeting the separation requirements given in 85.2 (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). Dectilorriate water test samples containing chlorne 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 arid 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 llmlt Remove a part of the sample froni 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 preireated test sample may be stored for 72 h at about + 4 C. protected from light.
8 Procedure
8.1 ExtractIon
Homogenize the test sample, e.g. with a magnetic stirrer. Remove a part of the test sample from the sampling bottle until a test sample volume of about 1 000 ml ± 10 ml remains and determine the voltxne of the test sample by weighing the bottle, add 25 ml of hexane (5.1.2) and mix. Other volatile solvents may be used for extraction. provided they give equal or better recovery.