BS ISO 21330:2018 pdf download

BS ISO 21330:2018 pdf download.Cigarettes — Determination of selected volatile organic compounds in the mainstream smoke of cigarettes — Method using GC/MS
7.2.3.3 Calibration standard solutions (for isoprene, acrylonitrile, benzene and toluene)
Prepare seven working standard solutions by mixing appropriate volumes of secondary stock solution (7.2.3.2) and internal standard spiking solution (7.2.2.2) to cover the concentration range of interest, i.e. (12 – 600) µg/ml (isoprene); (4 – 200) µg/ml (acrylonitrile); (4 – 200) µg/ml (benzene); (4 – 200) µg/ml (toluene) and 40 µg/ml of internal standard (e.g. benzene-D 6 ). The concentration change of the highest calibration standard solution after adding internal standard solution should not be significant. Transfer aliquots of each calibration standard solution into amber GC vials and fill each vial up to the shoulder of the vial to minimize headspace. Adjust standard concentrations accordingly to reflect levels of volatiles found in smoke samples. PTFE lined GC vial caps are recommended, although other materials may also be suitable.
7.2.4.3 Determination of secondary 1,3-butadiene stock concentration
Pipette 1 ml of the secondary 1,3-butadiene stock solution (7.2.4.2) into a 100 ml volumetric flask and dilute to volume using ethanol. This solution is used only to check the concentration of the secondary stock solution and shall not be used to prepare the working standards. Measure the absorbance of the solution against an ethanol blank on a spectrophotometer (use 1 cm long cuvettes). Conduct a wave scan from 200 nm to 250 nm to determine the wavelength of maximum absorbance. 1,3-butadiene in hexane absorbs at 217 nm whereas 1,3-butadiene in ethanol can have a peak shift. Measure the absorbance at the peak maximum. Repeat the above measurement three more times and calculate the mean absorbance, A (at least three significant figures). The absorbance should be between 0,2 and 0,6 extinction units. If it is higher, make a new secondary stock solution using a smaller volume of the primary stock solution and repeat the spectrophotometer measurements to determine the concentration of the secondary stock. If the absorbance is lower, make a new secondary stock solution using a larger volume of the primary stock solution and repeat the spectrometer measurements to determine the concentration of the secondary stock.
10.2 Smoking machine setup
An analytical cigarette-smoking machine complying with the requirements of ISO 3308 is required. A methanol-filled impinger system is required that efficiently traps the VOCs of interest. An example using two impingers is provided in Figure 1; however, other trapping systems using a different number of impingers, different impinger tip styles (capillary, fritted, etc.) and a different volume of trapping solution can also provide suitable trapping efficiency. Fill all coolant reservoirs with one-third full of isopropanol. Add dry ice until each reservoir is filled halfway. The number of reservoirs required is dependent on the impinger design and has to be optimized to ensure that all volatiles are trapped efficiently. Add 10 ml of methanol to each impinger and place the impingers into the coolant reservoir containing the dry ice/isopropanol solution. Check each coolant reservoir to ensure that the temperature is at or below –70 °C. A volume other than 10 ml of methanol may need to be added to each impinger depending on the particular style of impinger used. The impingers shall be given sufficient time to cool to −70 °C or below before starting smoke collection. Connect the impingers to the smoking machine (see Figure 1). Check and adjust the puff volume drawn by the smoking machine at all channels.