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1、INTERNATIONAL STANDARD IS0 4388 Second edition 1991-12-15 Cigarettes - Determination of the smoke condensate retention index of a filter - Direct spectrometric method Cigarettes - D, SC rf; + If c is the mass of crude smoke condensate retained by the filter; 2 Normative references The following stan
2、dards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the editions indicated were valid. All stan- dards are subject to revision, and parties to agreements based on this International Standard are encourage
3、d to investigate the possibility of ap- plying the most recent editions of the standards in- dicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IS0 3308:1991, Routine analytical cigarette-smoking machine - Definitions and standard conditions. IS0 340
4、2:1991, Tobacco and tobacco products - At- mosphere for conditioning and testing. IS0 4387:1991, Cigarettes - Determination of total and nicotine-free dry particulate matter using a rou- tine analytical smoking machine. IS0 8243:1991, Cigarettes - Sampling. is the mass of crude smoke condensate ente
5、ring the filter; is the mass of crude smoke condensate in the main-stream smoke. SC ; Hc Figure 1 4 Principle Smoking of filter cigarettes in accordance with IS0 4387. Dissolution in methanol of the crude smoke condensate from the main-stream smoke. Removal of the filter material from the remaining
6、tobacco butts; dissolution in methanol of the crude smoke condensate retained by the filters. Determination of the absorbances at 450 nm of the two methanolic solutions by spectrometric meas- urement and calculation of the retention index from 1 Copyright International Organization for Standardizati
7、on Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 21:17:12 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 4388:1991(E) the ratio of the absorbances. The absorbances are directly proportional to the masse
8、s of crude smoke condensate (F, and H,). 5 Reagent 5.1 Methanol, having a water content lower than 0,05 % (m/m). 6 Apparatus Usual laboratory apparatus not otherwise specified and the following items. 6.1 Conditioning enclosure, regulated in accord- ance with the requirements of IS0 3402. 6.2 Routin
9、e analytical cigarette-smoking machine, complying with the requirements of IS0 3308 and IS0 4387. 6.3 Spectrometer, suitable for carrying out meas- urements at a wavelength of 450 nm. 6.4 Matched quartz cells, having an optical path length of 10 mm, if necessary, 5 mm and/or 20 mm. 6.5 Volumetric fl
10、asks, of capacities 100 ml or 125 ml, with ground glass stoppers. 6.6 One-mark pipettes, of capacities 5 ml and 10 ml. 6.7 Centrifuge, capable of producing a relative centrifugal acceleration of 25 gl). 7 Sampling Carry out sampling in accordance with the method specified in IS0 8243. 6 Procedure 8.
11、1 Conditioning of the test sample Keep the test sample in the conditioning enclosure (6.1) until it attains constant mass. 8.2 Test portion Take, as the test portion, 20 filter cigarettes from the conditioned test sample (8.1). 8.3 Determination 6.3.1 Smoking of the cig,arettes Using the routine ana
12、lytical cigarette-smoking ma- chine (6.2), smoke the 20 filter cigarettes constituting the test portion (8.2) in accordance with IS0 4387. NOTE 1 The number of cigarettes smoked per trap de- pends on the diameter of the glass-fibre filter and the yield of crude smoke condensate of the cigarette. For
13、 a 44 mm smoke trap this number is in general 5. For a 9 2 mm smoke trap this number is in general 20. Extinguish the butts by separating the burning zone, remove the filter plugs and free them from any ad- hering tipping and plug wrap material and from any tobacco. 8.3.2 Preparation of methanolic c
14、rude smoke condensate solution 8.3.2.1 Combine the cigarette filter plugs from one channel of the smoking machine and put them into 100 ml of methanol (5.1) in a volumetric flask (6.5). Do the same with the filter plugs from the other channels. Stopper the flasks, swirl the contents of each flask an
15、d allow them to stand in the dark for about 24 h. 8.3.2.2 Remove the glass-fibre filter discs from the smoke traps and prepare from each disc a solution of the crude condensate in 100 ml of methanol (5.1) in a volumetric flask (6.5). Stopper the flasks, swirl the contents of each flask and allow the
16、m to stand in the dark for the same time as the methanolic solutions obtained from the cigarette filter plugs (8.3.2.1). 8.3.2.3 Transfer, by means of a pipette (6.6), 5 ml to IO ml of each of the crude smoke condensate solutions, prepared as described in 8.3.2.1 and 8.3.2.2, to the centrifuge (6.7)
17、 and centrifuge for ap- proximately 1 min to remove suspended matter. 8.3.3 Measurement Check that the absorbance of each cell (6.4) is the same before and after each measurement. Matched quartz cells with an optical path length of IO mm (6.4) are generally suitable for the spectro- metric measureme
18、nt, but see 10.3. Using the spectrometer (6.3), measure the optical absorbances of the clear supernatant crude smoke condensate solutions at 450 nm against a methanol blank. 1) 1 g=9,81 ms-* 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NA
19、SA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 21:17:12 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 4388:1991(E) Denote the absorbance values for the solutions from the cigarette filter plugs as Ar and the absorbance values for the solutions from the
20、 glass-fibre filter discs as A,. 9 Expression of results The smoke condensate retention index, R, of a cigarette filter, expressed as a percentage by mass, for each smoking machine channel is given by the formula R, = Fc I;,+ii, x1oo= A,/4 fkl4 + AH/b x 100 where 4 is the absorbance of the combined
21、filter plug extract for one channel, measured in a cell of optical path length Z, in milli- metres; AH is the absorbance of the extract from the glass-fibre filter disc corresponding to the same channel, measured in a cell of optical path length Z2, in millimetres. The calculation remains unchanged
22、if the method described in 10.3.2 is used. If the method described in 10.3.3 is used, the appropriate dilution factor shall be taken into account. For the cigarettes of each channel of the smoking machine, express the smoke condensate retention index, R, as a percentage by mass, to the nearest 1 %.
23、IO Notes on procedure 10.1 Separation of the butts and extraction of the filter plugs with methanol (8.3.2) shall be carried out with the minimum delay after each smoking run (8.3.1). 10.2 The absorbance at the chosen wavelength of a methanolic extract of glass-fibre filter disc blanks, of cellulose
24、 acetate and/or paper cigarette filters, should be the same as that of the methanol blank. 10.3 In order to obtain optimum accuracy, the absorbance values for the test solutions should lie between 0,l and 0,7. Generally, with a cell of optical path length of IO mm, the undiluted methanolic sol- utio
25、ns can be used. 10.3.1 If the absorbance is less than O,l, a cell of longer path length may be used. Similarly if the absorbance is greater than 0,7, a cell of shorter path length may be used. If the possibility of using a longer or shorter path length is excluded because of the construction of the
26、spectrometer, then one of the methods described in 10.3.2 or 10.3.3 may be used. 10.3.2 If the absorbance is less than O,l, select a wavelength shorter than 450 nm but not less than 350 nm. NOTE 2 Performing the determination at another wave- length influences only the level of absorbance and does n
27、ot affect the accuracy of the determination. Once the wavelength has been set for a particular deter- mination, this setting should not be altered until the da- termination has been completed. 10.3.3 If the absorbance is greater than 0,7, adjust the concentration by diluting an aliquot of the sam- p
28、le solution to a measured volume. NOTE 3 This is nearly always the case when smoking 20 cigarettes onto a 92 mm filter disc, where a dilution of the condensate solutions to a four times greater volume is recommended. 11 Test report The test report shall show the method used and the results obtained.
29、 It shall also mention any operating conditions not specified in this International Stan- dard or regarded as optional, as well as any cir- cumstances that may have influenced the results. The test report shall include all details required for complete identification of the sample. The test report s
30、hall, in particular, include the fol- lowing items of information: a) characteristic data about the cigarettes; b) sampling procedure, including 1) method of sampling, 2) number of cigarettes comprising the test sample, and 3) date and place of sampling; c) test and conditioning atmosphere, in accor
31、dance with IS0 3402: d) test results expressed in accordance with clause 9; e) .,date of the test. 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 21:17:12 MDTNo reproduction o
32、r networking permitted without license from IHS -,-,- IS0 4388:1991(E) UDC 663.974:620.1:543.42 Descriptors: tobacco, cigarettes, cigarette filters, smoke, condensates, chemical analysis, determination, retention index, spectrometric mef$d. Price based on 3 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 21:17:12 MDTNo reproduction or networking permitted without license from IHS -,-,-