1、BRITISH STANDARD BS 5202-10:2001 ISO 4389:2000 Methods for chemical analysis of tobacco and tobacco products Part 10: Determination of organochlorine pesticide residues (gas chromatographic method) ICS 65.160; 71.040.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS 5202-10
2、:2001 This British Standard, having been prepared under the direction of the Consumer Products and Services Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 May 2001 BSI 05-2001 ISBN 0 580 37228 6 National foreword This British Standard repro
3、duces verbatim ISO 4389:2000 and implements it as the UK national standard. It supersedes BS 5202-10:1998 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee AW/40, Tobacco and tobacco products, which has the responsibility to: A list of organizations rep
4、resented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”
5、, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself conf
6、er immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii and iii, pages 1 to 15 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. aid enquirers to und
7、erstand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Amendments issued since publication A
8、md. No. Date CommentsReference number ISO 4389:2000(E) INTERNATIONAL STANDARD ISO 4389 Third edition 2000-12-15 Tobacco and tobacco products Determination of organochlorine pesticide residues Gas chromatographic method Tabac et produits du tabac Dosage des rsidus de pesticides organochlors Mthode pa
9、r chromatographie en phase gazeuse BS520210:2001 ISO 9834:(0002)E ii BS520210:2001 ISO 9834:(0002)Eiii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normal
10、ly carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the
11、 work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technica
12、l committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent ri
13、ghts. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 4389 was prepared by Technical Committee ISO/TC 126, Tobacco and tobacco products. This third edition cancels and replaces the second edition (ISO 4389:1997). As a result of extensive ex
14、amination, the scope of this edition has been extended to tobacco products. Technical Corrigendum 1:1998 has been included. Annexes A and B of this International Standard are for information only. BS520210:2001 BS520210:2001 INTENRATIONAL TSANDADR ISO 9834:(0002)E1 Tobacco and tobacco products Deter
15、mination of organochlorine pesticide residues Gas chromatographic method 1 Scope This International Standard specifies a method for the gas chromatographic determination of pesticide residues in leaf tobacco, manufactured tobacco and tobacco products. The method is applicable to the determination of
16、 the organochlorine pesticides listed in Table 1. The method is particularly recommended for determination of the substances within the detection limits listed in Table 1. NOTE 1 The method has been demonstrated to be free from errors that may arise from interfering peaks on the chromatogram that or
17、iginate from non-organochlorine pesticide substances, when applied to various styles of leaf tobacco. However, the preceding statement cannot be assumed to apply to all forms and variants of tobacco and tobacco products and care should be taken in the interpretation of any unexpected, apparently pos
18、itive results. Some analysts advocate the use of mass spectrometric confirmation of the chemical structure of compounds detected by chromatography in such circumstances. NOTE 2 ISO 1750 contains the systematic chemical names and structures corresponding to the common names given in Table 1. 2 Normat
19、ive references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements bas
20、ed on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of curr
21、ently valid International Standards. ISO 648, Laboratory glassware One-mark pipettes. ISO 1042, Laboratory glassware One-mark volumetric flasks. ISO 3696, Water for analytical laboratory use Specification and test methods. ISO 4874, Tobacco Sampling of batches of raw material General principles. ISO
22、 8243, Cigarettes Sampling. BS520210:2001 ISO 9834:(0002)E 2 3P r i n c i p l e The pesticide residues from a dried and milled sample, mixed with Florisil 1 , are extracted by n-hexane in a special Soxhlet extractor. They are determined without any further clean-up with a gas chromatographic apparat
23、us equipped with an electron-capture detector. 4 Reagents All reagents shall be suitable for pesticide residue analysis. All solvents shall be checked for purity before use by carrying out a blank determination using exactly the same procedure (extraction and gas chromatography) as used for the test
24、 sample. The chromatogram obtained from the solvents shall have a baseline without noticeable peaks that could interfere with those from the pesticide residues being determined. 4.1 Water, degassed, in accordance with at least grade 2 of ISO 3696. 4.2 n-Hexane. 4.3 Toluene. 4.4 Reference substances:
25、 certified reference materials of minimum purity 95 % (mass fraction) of the substances listed in Table 1. NOTE trans-Chlordane is used as an indicator for chlordane (technical mixture). If -endosulfan is detected by this method, it is advisable to determine residues of the sum of -endosulfan, -endo
26、sulfan and endosulfan sulfate by a method suitable for such determinations. 4.5 Internal standard stock solution Use Mirex, 2) an obsolete pesticide which has been superseded (see reference 2). NOTE Mirex is a generic name for dodecachloropentacyclo5.2.1.0 2,6 .0 3,9 .0 5,8 decane. Weigh, to the nea
27、rest 0,000 1 g, 0,02 g of Mirex into a 100 ml volumetric flask. Dilute to the mark with n-hexane (4.2). 4.6 Internal standard solution Pipette 5 ml of the internal standard stock solution (4.5) into a 200 ml volumetric flask and dilute to the mark with n-hexane (4.2) to give a solution containing ap
28、proximately 5 g/ml of Mirex. Store the internal standard solution at between 0 C and +4 C and exclude light. Under these conditions the internal standard solution is stable for at least 6 months. 1 Florisil is an example of a suitable product available commercially. This information is given for the
29、 convenience of users of this International Standard and does not constitute an endorsement by ISO of this product. 2) Mirex is an example of a suitable product available commercially. This information is given for the convenience of users of this International Standard and does not constitute an en
30、dorsement by ISO of this product. BS520210:2001 ISO 9834:(0002)E3 Table 1 List of suitable pesticides with detection limits Substance Common name (ISO 1750) Detection limit g/g Aldrin aldrin 0,02 trans-Chlordane chlordane 0,02 p,p-DDE 0,02 o,p-DDT 0,04 p,p-DDT DDT 0,06 Dieldrin dieldrin 0,02 -Endosu
31、lfan endosulfan 0,03 HCB hexachlorobenzene 0,02 -HCH or -BHC HCH or BHC 0,02 -HCH or -BHC HCH or BHC 0,02 -HCH or -BHC gamma-HCH (lindane) or gamma-BHC 0,01 -HCH or -BHC HCH or BHC 0,02 Heptachlor heptachlor 0,02 Heptachlor epoxide 0,02 o,p-TDE or o,p-DDD 0,03 p,p-TDE or p,p-DDD TDE 0,02 o,p-DDE 0,0
32、3 4.7 Standard pesticide solutions Store all pesticide solutions at between 0 Ca n d+ 4C and exclude light. Under these conditions the solutions are stable for at least 6 months. 4.7.1 Individual standard stock solutions Weigh, to the nearest 0,000 1 g, 0,02 g of each pesticide reference substance (
33、4.4) into individual 100 ml volumetric flasks. Dilute to the mark with n-hexane (4.2) to give individual standard stock solutions containing approximately 200 g/ml of the individual pesticide. In the case of -HCH, the standard stock solution should be made by dissolving the pesticide in toluene (4.3
34、) because of reduced solubility in n-hexane. BS520210:2001 ISO 9834:(0002)E 4 4.7.2 Mixed stock solution A Pipette 5 ml of each individual standard stock solution (4.7.1) into a single 200 ml volumetric flask and dilute to the mark with n-hexane (4.2) or toluene (4.3) for -HCH to give a solution con
35、taining approximately 5 g/ml of each pesticide. 4.7.3 Mixed stock solution B Pipette 1 ml of mixed stock solution A (4.7.2) into a 10 ml volumetric flask and dilute to the mark with n-hexane (4.2) to give a solution containing approximately 0,5 g/ml of each pesticide. 4.7.4 Standard calibration solu
36、tion Pipette 1 ml of both the mixed stock solution A (4.7.2) and the internal standard solution (4.6) into a 100 ml volumetric flask and dilute to the mark with n-hexane (4.2) to give a solution containing approximately 0,05 g/ml of each pesticide and internal standard. 4.8 Florisil,15 0mto2 5 0m. N
37、OTE Florisil is a special, selected variety of magnesium silicate. The nominal aperture size of 150 m to 250 m corresponds to a mesh size range designated as 60 mesh to 100 mesh. 4.8.1 The quality of the Florisil is one of the most critical features of the test method. The activity of the Florisil m
38、ust be sufficient to retain impurities present in the extract from the sample while allowing the pesticide residues to be eluted. The Florisil shall first be pre-treated as described in 4.8.2. Only Florisil that passes the subsequent verification test described in 4.8.3 shall be used. 4.8.2 Heat suf
39、ficient Florisil for the verification test for at least 5 h in a quartz crucible in a muffle furnace at 550 C. Allow the Florisil to cool in a desiccator that contains no desiccant and transfer to a round-bottom flask. Add 5 ml of water (4.1) for every 100 g of Florisil. Mix thoroughly in a rotating
40、 flask for approximately 1 h. Allow the Florisil to equilibrate by storing in a tightly closed glass container for at least 48 h before proceeding as described in 4.8.3. 4.8.3 The activity level of the Florisil is checked by the extraction of dieldrin from n-hexane solution. The solution shall have
41、a concentration equivalent to that of an extract from tobacco containing 1,0 g/g of this pesticide. The activity level of the pretreated Florisil is correct if the recovery of dieldrin is better than 95 %. The activity of the Florisil shall be checked each time a new portion is prepared. 5 Apparatus
42、 It is essential to clean all glassware very thoroughly before use and to avoid the use of plastics containers and stopcock grease, otherwise impurities may be introduced into the solvents. All volumetric flasks and pipettes shall comply with class A of ISO 1042 and class A of ISO 648 respectively.
43、Usual laboratory apparatus and the following items. 5.1 Rotary evaporator. 5.2 Tobacco mill, with 2 mm mesh. 5.3 Oven, with ventilation. 5.4 Muffle furnace. 5.5 Heating mantles. BS520210:2001 ISO 9834:(0002)E5 5.6 Soxhlet extractor, for continuous extraction (see Figure 1). Key 1 Tobacco Florisil 2F
44、 l o r i s i l 3 Filter disk porosity 1 NOTE Distillation rate 200 ml/h. Figure 1 Apparatus used for tobacco extraction 5.7 Reflux condenser. 5.8 Desiccator. 5.9 Quartz crucible. BS520210:2001 ISO 9834:(0002)E 6 5.10 Gas chromatograph Operate the gas chromatograph in accordance with the manufacturer
45、s instructions. The injection port, oven and detector shall each be equipped with a separate heating unit. The following conditions have been found to be satisfactory on a particular make of instrument and are given for guidance. If other conditions are used they should be validated prior to use. a)
46、 Temperatures The injection port temperature shall be between 180 C and 210 C. The detector temperature shall be between 290 C and 340 C. If any other conditions are used they shall be sufficient to achieve satisfactory separation of all components and similar to that given in the specimen chromatog
47、ram (see Figure A.1 for an example). A suitable temperature programme is initial temperature 40 C initial time 2 min temperature profile 1 20 C/min from 40 Cto1 50C temperature profile 2 3 C/min from 150 Cto2 70C final time 15 min at 270 C total GC run time 62,5 min b) Gas flow rates Gas flow rates
48、should be set according to the instrument manufacturers guidance and the analysts experience. Suitable gas flow conditions are carrier gas helium, 4 ml/min make-up gas nitrogen, 30 ml/min septum purge 5 ml/min split vent 30 ml/min c) Injection mode Use 2 l splitless with split valve closed for 1 min
49、 after injection. 5.10.1 Injection device Use an automated injector or any suitable alternative means of injection. For manual injection, the use of a microsyringe capable of injecting 1 lt o5 l portions is recommended. Before solutions are injected with the syringe, rinse it at least ten times with n-hexane then five times with the solution. After injection, rinse the syringe five times with n-hexane. BS5202
