BS ISO 13276-2020 pdf free download.Tobacco and tobacco products – Determination of nicotine purity – Gravimetric method using tungstosilicic acid.
BS ISO 13276-2020 specifies a method for the gravimetric determination of the purity of nicotine using tungstosilicic acid.
BS ISO 13276-2020 is applicable to pure nicotine or nicotine salts used to calibrate analytical methods for the determination of nicotine in the field of tobacco, tobacco products and smoke analysis.
4 Principle
Complex formation of nicotine or its salts with tungstosilicic acid to form insoluble nicotine silicotungstate. Determination of the precipitate mass by filtration using either a sintered glass crucible in combination with oven-drying or an ashless filter paper in combination with incineration.
7.1 Precipitation procedure
A suitable amount of replicates should be measured Weigh, to the nearest 0,000 1 g, approximately
0, 1 g of the nicotine alkaloid ( or the equivalent amount of nicotine salt)(m) in each of, for example,five 250 ml beakers( 6.2) equipped with glass stirring rods.
Add 100 ml of water to each beaker. Add 2 ml of 20 hydrochloric acid solution (5.2 to each beaker and stir. Do not remove the stirring rod.
Add slowly 15 ml of the tungstosilicic acid solution (5.1)while stirring constantly during the addition Cover each beaker with a watch glass (6.3) leaving the stirring rod in place, and allow to stand overnight. Before filtering, stir the precipitate to ensure that it settles quickly and is of a crystalline form. Check for complete precipitation with a few extra drops of the tungstosilicic acid solution.
Take the arithmetic mean of the five determinations as the test result. Report the result to one decimal place.
Should nicotine salts be contaminated with residues of unreacted nicotine, results above 100 can be obtained by using this method as the method is specific for nicotine. These anomalous results can be considered as qualified for calibration purposes.