1、December 2015 English price group 8No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 65.160!%Izw“2388784www.din.deDIN
2、 ISO 10362-2Cigarettes Determination of water in smoke condensates Part 2: Karl Fischer method (ISO 10362-2:2013),English translation of DIN ISO 10362-2:2015-12Zigaretten Wasserbestimmung in Rauchkondensaten Teil 2: Karl-Fischer-Verfahren (ISO 10362-2:2013),Englische bersetzung von DIN ISO 10362-2:2
3、015-12Cigarettes Dosage de leau dans les condensats de fume Partie 2: Mthode de Karl Fischer (ISO 10362-2:2013),Traduction anglaise de DIN ISO 10362-2:2015-12SupersedesDIN ISO 10362-2:1995-04www.beuth.deDocument comprises 12 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-langua
4、ge original shall be considered authoritative.12.15Introduction 1 Scope .2 Normative references 3 Principle 4 Reagents 5 Apparatus .6 Procedure.6.1 General .6.2 Test portion 6.3 Blank test .6.4 Standardization of Karl Fischer reagent .6.5 Determination .7 Expression of results 98 Test report .Biblio
5、graphy 2Contents Pageoreword National f 3National Annex NA (informative) Bibliography . A comma is used as the decimal marker. 4DIN ISO 10362-2:2015-12 5666677771210988National foreword The responsible German body involved in its preparation was DIN-Normenausschuss Lebensmittel und landwirtschaftlic
6、he Produkte (DIN Standards Committee Food and Agricultural Products), Working Committee NA 057-04-01 AA Tabak und Tabakerzeugnisse. With the revision of the international standards dealing with smoke analysis, the gas-chromatographic method for determining water in smoke condensates has been introdu
7、ced. At its sixteenth plenary meeting (held in Havana, 1989), ISO/TC 126 decided to revise also the Karl Fischer Method for determining water in smoke condensates. Thus, International Standard ISO 10362-2 could be published in 1994 and a revised version in 2013. DIN ISO 10362 consists of the followi
8、ng parts, under the general title Cigarettes Determination of water in smoke condensates: Part 1: Gas-chromatographic method Part 2: Karl Fischer method Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. DIN shall not be held respons
9、ible for identifying any or all such patent rights. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 3308 DIN EN ISO 3308 ISO 3696 DIN ISO 3696 ISO 4387 DIN ISO 4387 ISO 10362-1 DIN ISO 10362-1 Amendments This standard differs from DIN I
10、SO 10362-2:1995-04 as follows: a) Amendment ISO 10362-2:1994/Amd. 1:2011 indicating that no machine smoking regime can represent all human smoking behaviour has been incorporated (see Introduction). The technical substance of the standard has not been changed; b) the distilled water used shall compl
11、y at least with grade 2 according to DIN ISO 3696; c) in Clause 6 “Procedure”, the subclauses have been restructured; d) Clause 8 “Test report” has been extended; e) the standard has been editorially revised. Previous editions DIN ISO 10362-2: 1995-04 3DIN ISO 10362-2:2015-12 This document (ISO 1036
12、2-2:2013) has been prepared by Technical Committee ISO/TC 126 “Tobacco and tobacco products” (Secretariat: DIN, Germany).National Annex NA (informative) Bibliography DIN ISO 3308, Routine analytical cigarette smoking machine Definitions and standard conditions DIN ISO 3696, Water for analytical labo
13、ratory use Specification and test methods DIN ISO 4387, Cigarettes Determination of total and nicotine-free dry particulate matter using a routine analytical smoking machine 4DIN ISO 10362-2:2015-12 DIN ISO 10362-1, Cigarettes Determination of water in smoke condensates Part 1: Gas-chromatographic m
14、ethodIntroductionNo machine smoking regime can represent all human smoking behaviour: it is recommended that cigarettes also be tested under conditions of a different intensity of machine smoking than those specified in this International Standard; machine smoking testing is useful to characterize c
15、igarette emissions for design and regulatory purposes, but communication of machine measurements to smokers can result in misunderstandings about differences in exposure and risk across brands; smoke emission data from machine measurements may be used as inputs for product hazard assessment, but the
16、y are not intended to be nor are they valid as measures of human exposure or risks. Communicating differences between products in machine measurements as differences in exposure or risk is a misuse of testing using ISO standards.Cigarettes Determination of water in smoke condensates Part 2: Karl Fis
17、cher method5DIN ISO 10362-2:2015-12 1 ScopeThis part of ISO 10362 specifies the use of the Karl Fischer method for the determination of water in cigarette smoke condensates. The smoking of cigarettes and collection of mainstream smoke are normally carried out in accordance with ISO 4387. However, th
18、e method is also applicable to the determination of water in smoke condensates obtained by non-standard smoking.NOTE ISO 4387 specifies the use of gas chromatography for the determination of water in smoke condensate solutions (see also ISO 10362-1). In countries not in a position to use the gas-chr
19、omatographic method, the determination of water in smoke condensate can be performed by the method described in this part of ISO 10362 and an appropriate note made in the expression of the results.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this
20、document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3308, Routine analytical cigarette-smoking machine Definitions and standard condition
21、sISO 4387, Cigarettes Determination of total and nicotine-free dry particulate matter using a routine analytical smoking machineISO 3696, Water for analytical laboratory use Specification and test methods3 PrincipleDissolution of the smoke condensate from the mainstream smoke in a solvent. Determina
22、tion of the water content of an aliquot of the solution by titration with standardized Karl Fischer reagent.4 ReagentsUse only reagents of recognized analytical reagent grade and distilled water complying with grade 2 of ISO 3696 or better.4.1 Propan-2-ol, (CH3)2CHOH, extraction solvent.NOTE Propan-
23、2-ol normally contains a small amount of water which is determined as a blank as outlined in the procedure. It is not recommended that specially dried solvent (e.g. using a molecular sieve) should be used since in this state it is extremely hygroscopic and further handling problems are introduced.4.
24、2 Karl Fischer reagent (KFR), which can be obtained commercially in two forms:a) as a single reagent with an initial water equivalent of approximately 5 mg/ml; this value decreases on storage;b) as two separate reagents (Karl Fischer solution A: methanol, pyridine, sulfur dioxide; Karl Fischer solut
25、ion B: methanol, iodine) which, when mixed in equal volumes, give a reagent with a water equivalent of approximately 3 mg/ml.Reagents which do not contain pyridine are preferred if these are available. If these are not available, take special care during handling. See also CAUTION concerning waste d
26、isposal in 6.4.1.4.3 Methanol, CH3OH, with a water content of less than 0,05 g per 100 g.4.4 Silica gel, freshly activated.6DIN ISO 10362-2:2015-12 5 ApparatusNormal laboratory apparatus and in particular the following items:5.1 Karl Fischer apparatus, preferably of the automatic or semi-automatic t
27、ype set up according to the manufacturers instructions for direct titration.5.2 Solvent dispenser. A suitable container type is a 5 l aspirator bottle with a silica gel moisture trap in the neck and the bottom outlet connected to a 25 ml double-action automatic pipette or an electronically operated
28、pipette. The silica gel has a drying effect on the surface of the solvent causing the water content to vary during use. To avoid this, stir the solvent continuously during use by mounting the dispenser on an automatic stirrer.5.3 Syringe, of capacity 20 l.5.4 Syringe, of capacity 10 ml, fitted with
29、a wide bore needle, or pipette of capacity 10 ml.5.5 Hot-air oven, capable of maintaining a temperature of (105 5) C.5.6 Flask shaker, horizontal-action type.6 Procedure6.1 GeneralCare shall be taken during all operations to avoid contamination from atmospheric moisture.All glassware used in the pre
30、paration of the test portion and in the water determination shall be heated at (105 5) C for at least 1 h after visible water has evaporated, and cooled and stored in a desiccator over silica gel until used.6.2 Test portionThe following procedure shall be used when cigarettes are smoked in accordanc
31、e with ISO 4387. When non-standard smoking or collection of smoke condensate has been used, the procedure described below shall be modified accordingly to give a suitable smoke condensate solution. In this event, a note of the alternative procedure shall be included with the test results.Collect the
32、 cigarette smoke condensate in accordance with ISO 4387 on a routine analytical cigarette smoking machine complying with the requirements of ISO 3308.Wearing gloves, remove the sealing devices from the smoke trap, open it and remove the filter discN1)with forceps. Place the folded disc in a dry coni
33、cal flask (maximum 150 ml for 44 mm discsN1);maximum 250 ml for 92 mm discsN1). Wipe the inner surface of the filter-holder front with two separate quarters of an unused conditioned filter discN1)and add these to the flask. N1)National footnote: In ISO 10362-2:2013, the terms “filter disc(s)” and “d
34、isc(s)” (German term “Filter-scheibe(n)”) are used. Based on ISO 3308, this should read “glass fibre filter” (corresponding German term “Glasfaserfilter”). 7DIN ISO 10362-2:2015-12 6.3 Blank testDue to the absorption of water by smoke traps and solvent, determine a value for the sample blank. Prepar
35、e sample blanks by treating additional smoke traps (at least 2 per 100 cigarettes smoked) in the same manner as that used for smoke collection. Place them near the smoking machine during smoking, and extract and analyse them together with the smoke samples.6.4 Standardization of Karl Fischer reagent
36、6.4.1 Standardization procedureAdd sufficient methanol (4.3) to the Karl Fischer titration vessel (5.1) to immerse the tips of the electrodes. Titrate any residual solution (see note) in the titration vessel to its end-point by addition of Karl Fischer reagent (KFR).Using the 20 l syringe (5.3), add
37、 20 l (VW) of water to the titration vessel. To ensure that the syringe does not contain air bubbles, fill it to above the 20 l mark, invert it and tap the air bubbles to the top. Then depress the plunger to the 20 l mark and remove excess water quickly from the needle tip with a tissue.As an altern
38、ative, fill the syringe with 20 l of water and weigh the syringe. After dosage, weigh the syringe again and note the exact mass of water.Transfer the volume (VW) of water to the titration vessel taking care to inject the water directly into the solution, not allowing any to fall on to the neck or wa
39、lls of the vessel. Where the vessel can be fitted with a rubber membrane cap, this shall be used and the needle inserted through the cap. If a water droplet remains on the needle tip, remove it by touching the surface of the solution in the vessel.Titrate with KFR (4.2) and record the titration valu
40、e.Repeat the process and again record the titration value. Repeat a third time. Calculate the mean titration volume (Vt)Standardize the KFR every working day.For best results with the Karl Fischer technique, it is important to ensure that all stages of the analysis are carried out in a uniform manne
41、r, extract-to-extract, sample-to-sample, day-to-day.NOTE It is common practice with the direct-titration technique to carry out a titration “on top of” residual solution in the titration vessel, i.e. without removing the residual solution. When the volume in the vessel reaches a certain level, the l
42、iquid is run to waste, retaining just sufficient for the electrode tips to be immersed. In time, however, the methanol concentration in the vessel falls to a level such that the reaction cannot proceed satisfactorily. A precipitate may form and false titration values be obtained. Only experience wil
43、l tell when titrating “on top of” residual solution has reached this point and then the titration vessel should be completely emptied to waste, rinsed, and recharged with methanol.CAUTION Waste from the titration vessel should be run into a container which is kept stoppered until such time as safe d
44、isposal can be arranged, preferably through a waste-disposal agency, or in compliance with other national regulations.Run an appropriate quantity of extraction solvent (4.1) into the flask. The folded discN1)shall be covered with solvent. In the case of a 44 mm glass fibre filter trapN2), 25 ml is n
45、ecessary. In the case of a 92 mm glass fibre filter trapN2), 50 ml is necessary. Stopper the flask immediately and shake gently on an electric flask shaker (5.6) for at least 20 min, ensuring that the discN1)does not disintegrate. This provides the smoke condensate solution. N1)National footnote: In
46、 ISO 10362-2:2013, the terms “filter disc(s)” and “disc(s)” (German term “Filter-scheibe(n)”) are used. Based on ISO 3308, this should read “glass fibre filter” (corresponding German term “Glasfaserfilter”). N2)National footnote: In ISO 10362-2:2013, the term “glass fibre filter trap” is erroneously
47、 used. The correct procedure in this case is to fold the glass fibre filter and cover it with solvent. 8DIN ISO 10362-2:2015-12 6.4.2 Calculation of water equivalentThe water equivalent, E, of the Karl Fischer reagent, expressed in milligrams of water per millilitre, is given by the equationEmV=Wt(1
48、)wheremWis the mass, in milligrams, of the volume of water (VW) used for the standardization of the Karl Fischer reagent;Vtis the mean volume, in millilitres, of the Karl Fischer reagent used for the titration of the water.6.5 DeterminationAdd to the titration vessel 10 ml of the propan-2-ol extract
49、 from the blank, preferably using a syringe with a wide-bore needle (5.4) to enable rapid transfer. Titrate with KFR and record the titration volume.Repeat and again record the titration volume. Determine the mean titration volume for the blank, VB. Repeat the duplicate determination for all sample blanks.Add 10 ml of the smoke condensate solution to the titration vessel. Use a minimum volume of solution to wash the syringe or pipette since the residue of the extract may be required for the determination of nicotine. Titrate with KFR
