BS ISO 10362-2-2013 Cigarettes Determination of water in smoke condensates Karl Fischer method《香烟 烟雾冷凝物中水的测定 卡尔费休法》.pdf

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1、BSI Standards PublicationBS ISO 10362-2:2013Cigarettes Determination ofwater in smoke condensatesPart 2: Karl Fischer methodBS ISO 10362-2:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 10362-2:2013.It supersedes BS ISO 10362-2:1994+A1:2011 which is withd

2、rawn.The UK participation in its preparation was entrusted to TechnicalCommittee AW/40, Tobacco and tobacco products.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract

3、. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 79519 0ICS 65.160Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of

4、 theStandards Policy and Strategy Committee on 30 September 2013.Amendments issued since publicationDate Text affectedBS ISO 10362-2:2013 ISO 2013Cigarettes Determination of water in smoke condensates Part 2: Karl Fischer methodCigarettes Dosage de leau dans les condensats de fume Partie 2: Mthode d

5、e Karl FischerINTERNATIONAL STANDARDISO10362-2Second edition2013-10-01Reference numberISO 10362-2:2013(E)BS ISO 10362-2:2013ISO 10362-2:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no part of this publication may be repro

6、duced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester

7、.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 10362-2:2013ISO 10362-2:2013(E) ISO 2013 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative reference

8、s 13 Principle 14 Reagents 15 Apparatus . 26 Procedure. 26.1 General . 26.2 Test portion 26.3 Blank test . 36.4 Standardization of Karl Fischer reagent . 36.5 Determination . 47 Expression of results 48 Test report . 5Bibliography 7BS ISO 10362-2:2013ISO 10362-2:2013(E)ForewordISO (the International

9、 Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been est

10、ablished has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardiz

11、ation.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance wi

12、th the editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directivesAttention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent

13、 rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received. www.iso.org/patentsAny trade name used in this document is information given for the convenience of users and does not constitute an endorsement.The committee

14、 responsible for this document is ISO/TC 126, Tobacco and tobacco products.This second edition cancels and replaces the first edition (ISO 10362-2:1994), which has been technically revised.ISO 10362 consists of the following parts, under the general title Cigarettes Determination of water in smoke c

15、ondensates: Part 1: Gas-chromatographic method Part 2: Karl Fischer methodiv ISO 2013 All rights reservedBS ISO 10362-2:2013ISO 10362-2:2013(E)IntroductionNo machine smoking regime can represent all human smoking behaviour: it is recommended that cigarettes also be tested under conditions of a diffe

16、rent intensity of machine smoking than those specified in this International Standard; machine smoking testing is useful to characterize cigarette emissions for design and regulatory purposes, but communication of machine measurements to smokers can result in misunderstandings about differences in e

17、xposure and risk across brands; smoke emission data from machine measurements may be used as inputs for product hazard assessment, but they are not intended to be nor are they valid as measures of human exposure or risks. Communicating differences between products in machine measurements as differen

18、ces in exposure or risk is a misuse of testing using ISO standards. ISO 2013 All rights reserved vBS ISO 10362-2:2013BS ISO 10362-2:2013Cigarettes Determination of water in smoke condensates Part 2: Karl Fischer method1 ScopeThis part of ISO 10362 specifies the use of the Karl Fischer method for the

19、 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, the method is also applicable to the determination of water in smoke condensates obtained by non-standard smoking.NOTE I

20、SO 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-chromatographic method, the determination of water in smoke condensate can be performed by the method described in this p

21、art 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 document and are indispensable for its application. For dated references, only the edition cited applies. For undated

22、references, the latest edition of the referenced document (including any amendments) applies.ISO 3308, Routine analytical cigarette-smoking machine Definitions and standard conditionsISO 4387, Cigarettes Determination of total and nicotine-free dry particulate matter using a routine analytical smoki

23、ng machineISO 3696, Water for analytical laboratory use Specification and test methods3 PrincipleDissolution of the smoke condensate from the mainstream smoke in a solvent. Determination of the water content of an aliquot of the solution by titration with standardized Karl Fischer reagent.4 Reagents

24、Use 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-2-ol normally contains a small amount of water which is determined as a blank as outlined in the procedure. It is not

25、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.4.2 Karl Fischer reagent (KFR), which can be obtained commercially in two forms:a) as a single reagent with an initial w

26、ater equivalent of approximately 5 mg/ml; this value decreases on storage;INTERNATIONAL STANDARD ISO 10362-2:2013(E) ISO 2013 All rights reserved 1BS ISO 10362-2:2013ISO 10362-2:2013(E)b) as two separate reagents (Karl Fischer solution A: methanol, pyridine, sulfur dioxide; Karl Fischer solution B:

27、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 disposal

28、 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.5 ApparatusNormal laboratory apparatus and in particular the following items:5.1 Karl Fischer apparatus, preferably of the automatic or semi-automatic type set up according to the manu

29、facturers 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 pipette. The silica gel has a dr

30、ying 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 a wide bore needle, or pipette o

31、f 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 preparation of the test portion and

32、 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 accordance with ISO 4387. When non-standa

33、rd 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 cigarette smoke condensate in a

34、ccordance 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 disc with forceps. Place the folded disc in a dry conical flask (maximum 150 ml for 44 m

35、m discs; maximum 250 ml for 92 mm discs).2 ISO 2013 All rights reservedBS ISO 10362-2:2013ISO 10362-2:2013(E)Wipe the inner surface of the filter-holder front with two separate quarters of an unused conditioned filter disc and add these to the flask.Run an appropriate quantity of extraction solvent

36、(4.1) into the flask. The folded disc shall be covered with solvent. In the case of a 44 mm glass fibre filter trap, 25 ml is necessary. In the case of a 92 mm glass fibre filter trap, 50 ml is necessary.Stopper the flask immediately and shake gently on an electric flask shaker (5.6) for at least 20

37、 min, ensuring that the disc does not disintegrate. This provides the smoke condensate solution.6.3 Blank testDue to the absorption of water by smoke traps and solvent, determine a value for the sample blank. Prepare sample blanks by treating additional smoke traps (at least 2 per 100 cigarettes smo

38、ked) 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 reagent6.4.1 Standardization procedureAdd sufficient methanol (4.3) to the Karl Fischer titr

39、ation 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 20 l (VW) of water to the titration vessel. To ensure that the syringe does not cont

40、ain 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 alternative, fill the syringe with 20 l of water and weigh the syringe. After dosage, weigh

41、 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 walls of the vessel. Where the vessel can be fitted with a rubber membrane cap, this sh

42、all 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 value.Repeat the process and again record the titration value. Repeat a third time. Calcu

43、late 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 manner, extract-to-extract, sample-to-sample, day-to-day.NOTE It is common practice with t

44、he 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 liquid is run to waste, retaining just sufficient for the electrode tips to be immerse

45、d. 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 will tell when titrating “on top of” residual solution has reached this point and then t

46、he 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 disposal can be arranged, preferably through a waste-disposal agency, or in compliance

47、 with other national regulations. ISO 2013 All rights reserved 3BS ISO 10362-2:2013ISO 10362-2:2013(E)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)wheremWis the mass, in mi

48、lligrams, 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 from the blank, preferabl

49、y 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 and record t