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ISO 10362-2-2013 pdf free download
ISO 10362-2-2013 pdf free download.Cigarettes Determination of water in smoke condensates Part 2:Karl Fischer method
Cigarettes — Dosage de l’eau dans les condensats defumée — Partie 2: Méthode de Karl Fischer.
Wipe the inner surface of the filter-holder front with two separate quarters of an unused conditioned filter disc and add these to the flask.
Run an appropriate quantity of extraction solvent (4.1) into the flask. The folded disc shall be covered with solvent. In the case of a 44 mm glass fibre filter trap, 25 ml is necessary. In the case of a 92 mm glass fibre filter trap. 50 ml is necessary.
Stopper the flask immediately and shake gently on an electric flask shaker (&6) for at least 20 mm, ensuring that the disc does not disintegrate. This provides the smoke condensate solution.
6.3 Blank test
Due to the absorption of water by smoke traps and solvent, determine a value for the sample blank. Prepare sample blanks by treating additional smoke traps (at least 2 per 100 cigarettes smoked) in the same manner as that used for smoke collection. Place them near the smoking machine during smoking, and extract and analyse theni together with the smoke samples.
6.4 Standardization of Karl Fischer reagent
6.4.1 Standardization procedure
Add suilicient methanol (4.3) to the Karl Fischer titration vessel to immerse the tips of the electrodes. Titrate any residual solution (see note) in the titration vessel to its end-point by addition of Karl Fischer reagent (K FR).
Using the 20 i.il syringe (5), add 20 p1 (Vw) of water to the titration vessel. To ensure that the syringe does not contain air bubbles, fill it to above the 20 p1 mark, invert it and tap the air bubbles to the top. Then depress the plunger to the 20 p1 mark and remove excess water quickly from the needle tip with a tissue.
As an alternative, fill the syringe with 20 p1 of water and weigh the syringe. After dosage, weigh the syringe again and note the exact mass of water.
Transfer the volume (V) of water to the titration vessel taking care to inject the water directly into the solution, not allowing any to fall on to the neck or walls of the vessel. Where the vessel can be fitted with a rubber membrane cap, this shall be used and the needle inserted through the cap. If a water droplet remains on the needle tip, remove it by touching the surface of the solution in the vessel.
Titrate with KFR (4.2) and record the titration value.
Repeat the process and again record the titration value. Repeat a third time. Calculate the mean titration volume (Vi).
Standardize the KFR every working day.ISO 10362-2-2013 pdf free download.
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