BS ISO 16632:2021 pdf download.Tobacco and tobacco products一Determination of water content – Gas-chromatographic method. 5.5 ExtractIon solution: methanol (52) containing 2,0 ml of internal standard (5.3) per litre. The extraction solution is hygroscopic, so it is recommended to cap the bottle with an automatic delivery pipette equipped with a drying tube 5.6 Desiccant: silica gel1), freshly activated, or other effective agents. 5.7 Calibration solutions 5.7.1 General Prepare a series of at least four calibration solutions whose concentrations of added water cover the range expected to be found in the test portion by adding weighed amounts of water (SA) to the extraction solution (5.5). One of these calibration solutions shall be the extraction solution with no added water (solvent blank). To prevent water being absorbed, the bulk extraction solution container shall be fitted with a water trap and all solutions shall be kept sealed. The extraction solution shall be stirred continuously to ensure the homogeneity of the water concentration. The calibration solutions shall be made up using an extraction solution from the same batch used in 8.1. Transfer them to injection vials and cap immediately. It is recommended that the calibration solutions be made up at least each week. The standard preparation procedure is given as an example and is applicable for the range of the products in a collaborative studyL-1l. See Table 1. 5.7.2 Water stock solution. Transfer 25,000 g of water into a dry 500 ml volumetric flask Dilute to volume with extraction solution (5.5) and mix. 5.7.3 Working standards. Transfer the specified volumes of water stock solution (512) according to the table below into dry 100 ml volumetric flasks, containing approximately 25 ml of extraction solution (5S). Bring to a final volume with extraction solution (5.5) and mix. 6 Apparatus Usual laboratory apparatus and, in particular, the following items. All glassware used in the preparation and in the water determination shall be prepared to remove any water residue. Volumetric glassware shall be air-dried and stored in a desiccator over desiccant (5k) until used. All other glassware shall be heated at (105 ± 5) °C for at least 1 h after visible water has evaporated. The glassware shall then be cooled and stored in a desiccator over desiccant () until used. 6.1 Extraction vessels, for example of capacity 125 ml, dry serum bottles with crimp caps, or conical flasks with ground glass lids, or equivalent. It is especially important...
Download Address
Download