ISO 662:2016 pdf free
ISO 662:2016 pdf free.Animal and vegetable fats and oils一Determination of moisture and volatile matter content
Weigh, to the nearest 0,001 g, approximately 20 g of the test sample (Clause 6) into the dish (7.1.2) which has been previously dried and then weighed together with the thermometer (7.1.3).
Heat the dish containing the test portion (7.2.1) on the sand bath or electric hotplate (7.1.4), allowing the temperature to rise at a rate of about 10 °C/min up to 90 °C, and stirring constantly with the thermometer.
Reduce the rate of heating, observing the rate at which bubbles rise from the bottom of the dish, and allow the temperature to rise to 103 °C±2 °C. Do not heat above 105。C. Continue to stir, scraping the bottom of the dish until all evolution of bubbles has ceased.
To ensure the removal of all moisture, repeat the heatingto 103°C±2°C several times, coolingto 95 °C between the heating periods. Then allow the dish and thermometer to cool in the desiccator (7.1.5) to room temperature and weigh to the nearest 0,001 g. Repeat this operation until the difference between the results of two successive weighings does not exceed 2 mg.
Weigh, to the nearest 0,001 g, approximately 5 g or 10 g of the test sample (Clause 6), according to the expected moisture and volatile matter content, into the vessel (8.1.2), which has been previously dried and then weighed.
Keep the vessel containing the test portion (8.2.1) for 1 h in the drying oven (8.1.3), set at 103 °C. Allow to cool to room temperature in the desiccator (8.1 4) and then weigh to the nearest 0,001 g. Repeat the operations of heating, cooling and weighing, but use successive periods in the oven of 30 min each, until the loss in mass between two successive weighings does not exceed 2 mg or 4 mg, according to the mass of the test portion.
NOTE An increase of mass of the test portion after repeated heating indicates that autoxidation of the fat or oil has occurred. In this case, take for calculation of the result the smallest mass recorded or, preferably, use method A.ISO 662 pdf download.
