《BS-EN-12857-1999.pdf》由会员分享,可在线阅读,更多相关《BS-EN-12857-1999.pdf(16页珍藏版)》请在三一文库上搜索。
1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 12857:1999 The Euro
2、pean Standard EN 12857:1999 has the status of a British Standard ICS 67.040 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Foodstuffs Determination of cyclamate High performance liquid chromatographic method Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 16:07:39 GMT+
3、00:00 2006, Uncontrolled Copy, (c) BSI 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 September 1999 BSI 09-1999 ISBN 0 580 32595 4 BS EN
4、12857:1999 Amendments issued since publication Amd. No.DateComments National foreword This British Standard is the English language version of EN 12857:1999. The UK participation in its preparation was entrusted to Technical Panel AW/-/3, Food analysis Horizontal methods, which has the responsibilit
5、y to: aid enquirers to understand the text; present to the responsible 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. A list of organizations r
6、epresented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled International Standards Correspo
7、ndence Index, 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 i
8、tself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 13 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Licensed Copy: sheffieldun
9、sheffieldun, na, Sat Oct 28 16:07:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARDEN 12857 NORME EUROPENNE EUROPISCHE NORMApril 1999 ICS 67.050 English version Foodstuffs Determination of cyclamate High performance liquid chromatographic method Produits alimentaires Dosage du cyclamat
10、e Mthode par chromatographie liquide haute performance Lebensmittel Bestimmung von Cyclamat Hochleistungs flssigchromatographisches Verfahren This European Standard was approved by CEN on 16 April 1999. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the con
11、ditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in thre
12、e official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Aus
13、tria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Centra
14、l Secretariat: rue de Stassart, 36 B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members Ref. No. EN 12857:1999 E Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 16:07:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2 E
15、N 12857:1999 BSI 09-1999 Contents Page Foreword2 1 Scope3 2 Normative references3 3 Principle3 4 Reagents3 5 Apparatus and equipment4 6 Procedure5 7 Calculation7 8 Precision8 9 Test report9 Annex A (informative) Determination of the chlorine content in hypochlorite solutions10 Annex B (informative)
16、Figures11 Annex C (informative) Precision data13 Annex D (informative) Bibliography13 Foreword This European Standard has been prepared by Technical Committee CEN/TC 275, Food analysis Horizontal methods, the Secretariat of which is held by DIN. This European Standard shall be given the status of a
17、national standard, either by publication of an identical text or by endorsement, at the latest by October 1999, and conflicting national standards shall be withdrawn at the latest by October 1999. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followin
18、g countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, S
19、at Oct 28 16:07:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 3 EN 12857:1999 BSI 09-1999 1 Scope This European Standard specifies a high performance liquid chromatographic (HPLC) method for the determination of sodium cyclamate in foodstuffs 1, 2, 3. The method has been validated in an inter-l
20、aboratory test according to ISO 5725:1986 4 which has been carried out with lemonade, orange juice beverage, fruit yogurt and spray cream. In addition to the matrices investigated in the inter-laboratory test, experiences have shown that the method is also applicable to various foodstuffs such as gh
21、erkins, canned morello cherries, pineapple, orange nectar, apricot jam, blackberry jam, cherry nectar, hard candy, mixed fruit yogurt, strawberry yogurt, fruit quark, rice-pudding-apple-raisins, chocolate custard powder, cream dessert vanilla powder, vanilla ice and passion fruit-orange ice cream 2,
22、 3. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or re
23、visions of any of these publications apply to this draft European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN ISO 3696, Water for analytical laboratory use Specification and test methods. (ISO 36
24、96:1987) 3 Principle Sodium cyclamate is extracted from the sample with water, converted to N,N-dichlorocyclohexylamine and determined by HPLC on a reversed-phase column using UV detection at a wavelength of 314 nm. 4 Reagents During the analysis, unless otherwise stated, use only reagents of recogn
25、ized analytical grade and water of at least grade 1 as defined in EN ISO 3696. When preparing solutions, the purity of the substances shall be taken into account. 4.1 Methanol, for HPLC. 4.2 n-Heptane, for HPLC. 4.3 Light petroleum, having a boiling range from 40 C to 60 C. 4.4 Sodium sulfate, anhyd
26、rous. If necessary, wash with n-heptane to remove lipophilic contaminants. 4.5 Sodium carbonate solution, (Na2CO3) = 50 g/l1). 4.6 Sodium hypochlorite solution (1,7 % active chlorine) Dilute commercially available sodium hypochlorite solution containing more than 1,7 % active chlorine with water to
27、get a mass fraction of 1,7 % of active chlorine. Check the content of active chlorine of the sodium hypochlorite solution regularly, e.g. using the procedure as described in annex A. 4.7 Sulfuric acid, w(H2SO4) = 50 %2) 1) is the mass concentration. 2) w is the mass fraction. Licensed Copy: sheffiel
28、dun sheffieldun, na, Sat Oct 28 16:07:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 4 EN 12857:1999 BSI 09-1999 4.8 Sodium cyclamate standard solutions Weigh, to the nearest 0,1 mg, about 898 mg of sodium cyclamate in a 200 ml volumetric flask and dilute to the mark with water, (cyclohexylsulfa
29、mic acid) = 800 mg/200 ml3). Pipette 0,25 ml, 1 ml, 2,5 ml, 5 ml, 10 ml and 20 ml of this solution in 100 ml volumetric flasks and dilute to the mark with water. The cyclohexylsulfamic acid concentration of these solutions is 10 mg/l, 40 mg/l, 100 mg/l, 200 mg/l, 400 mg/l and 800 mg/l. 4.9 Carrez so
30、lution No. 1 Dissolve 15 g of potassium hexacyanoferrate (II) (K4Fe(CN)6 3H2O) with a mass fraction of at least 99 % in water and dilute to 100 ml. 4.10 Carrez solution No. 2 Dissolve 30 g zinc sulfate (ZnSO4 7H2O) with a mass fraction of at least 99,5 % in water and dilute to 100 ml. 4.11 Mobile ph
31、ase Mix 80 parts per volume methanol (4.1) with 20 parts per volume water, filter through suitable membrane filters, e.g. of pore size 0,45 m and degas, e.g. for 5 min in an ultrasonic bath. If neccessary, the proportion of methanol to water in the mobile phase may have to be modified slightly, to a
32、chieve adequate results with the column used. 4.12 Conditioning solution for HPLC, EDTA solution, (EDTA) = 10 g/l, filter through suitable membrane filters, e.g. of pore size 0,45 m and degas, e.g. for 5 min in an ultrasonic bath 4.13 Cellulose, powdered, with a mass fraction of at least 99,9 %, aci
33、d washed. 5 Apparatus and equipment Usual laboratory apparatus and, in particular, the following. 5.1 HPLC apparatus, comprising the following. 5.1.1 High performance liquid chromatograph, consisting of a pump, a sample injector, an ultraviolet (UV) spectrometer (capable of operating at a wavelength
34、 of 314 nm, preferably a diode array detector), with a recorder and/or integrator which allows the measurement of peak heights and peak areas. 5.1.2 Analytical reversed phase separating column, e.g. with: a RP C 18 stationary phase of 5 m; a length of 250 mm; internal diameter of 4 mm; a guard colum
35、n, RP C 18 (optional, but recommended especially for all solid sample materials). Performance criterion for suitable analytical columns is the baseline resolution of the cyclamate peak. Whenever interferences are identified with a diode array detector or by measurement at a second wavelength, an alt
36、ernative chromatographic condition shall be chosen for the determination of cyclamate. 5.2 Ultrasonic bath. 5.3 Membrane filter, of suitable pore size, e.g. 0,45 m. 3) The conversion factor from sodium cyclamate to cyclohexylsulfamic acid is 0,890 9. Licensed Copy: sheffieldun sheffieldun, na, Sat O
37、ct 28 16:07:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 5 EN 12857:1999 BSI 09-1999 5.4 Filtration unit, with filter holder for membrane filter for filtering and degassing mobile phase (4.11) and conditioning solution (4.12). 5.5 Homogenizer. 5.6 Water bath, capable of being maintained at 60
38、C. 5.7 Centrifuge, capable of producing a centrifugal acceleration of at least 1 400g at the base of the centrifuge tubes (5.8). 5.8 Centrifuge tubes, preferably made of glass, of suitable capacity, e.g 50 ml, sealable. 5.9 Separating funnels, of suitable capacity, e.g. 50 ml and 100 ml. 5.10 Fluted
39、 filter paper, medium fast, qualitative. 5.11 Phase separation filters, (optional). 6 Procedure 6.1 Preparation of the sample solutions 6.1.1 Liquid products and products giving clear solutions (e.g. clear fruit juices, filtered gherkin brine, hard candy) Dilute liquid products, filtered if necessar
40、y, with water to give a cyclamate content of approximately 400 mg/l or take liquid products directly for derivatization. Dissolve solid products in water to give a clear solution having a cyclamate content of approximately 400 mg/l. 6.1.2 Semi solid samples, (e.g. dairy products, desserts, spray cre
41、am, cloudy juices, jams, marmalades) Homogenize the sample thoroughly for 1 min. Weigh, to the nearest 1 mg, about 15 g of the sample into a 100 ml volumetric flask, add 80 ml of water and place the flask for approximately 10 min in an ultrasonic bath (5.2). Any other mass of the sample may be chose
42、n yielding a cyclamate content of not more than 400 mg/l in the 100 ml volumetric flask. Add 1 ml to 2 ml of Carrez solution No. 1 (4.9), mix, and add the same volume of Carrez solution No. 2 (4.10). Mix, dilute to the mark with water. Filter through a fluted filter paper, discarding the first 10 ml
43、 of the filtrate. To make allowance for the volume of any precipitate, if the fat-free insoluble matter in the initial sample mass exceeds approximately 3 g, it is advisable to centrifuge the clarified sample mixture for 10 min at a centrifugal acceleration of at least 1 400g before filtering it qua
44、ntitatively into the 100 ml volumetric flask. Wash the settled matter twice with water and centrifuge again, collect each of the supernatants in the 100 ml volumetric flask and then dilute the solution to the mark with water. This procedure may also be followed when the amount of insoluble matter is
45、 less than 3 g. Take 20 ml of this solution for derivatization (see 6.2). 6.1.3 Chocolate and related products Weigh, to the nearest 1 mg, about 15 g of the sample into a centrifuge tube (5.8) and stand the centrifuge tube in a water bath at 60 C until the sample melts completely. Carefully and slow
46、ly add 25 ml of light petroleum (4.3), mix thoroughly, seal the centrifuge tube and place it in an ultrasonic bath for 30 s and mix again. Centrifuge the sealed centrifuge tubes for 10 min at at least 1 400g. Decant the light petroleum layer and repeat the extraction with 25 ml of light petroleum, a
47、gain decanting the light petroleum layer. Evaporate the remaining light petroleum by placing the centrifuge tube for 15 min in a water bath at 60 C and mixing. Add 30 ml of water and mix thoroughly. Stand the centrifuge tube for 5 min in the ultrasonic bath. Transfer the solution with approximately
48、40 ml of water quantitatively into a 100 ml volumetric flask, add 1 ml of Carrez solution No. 1 (4.9), mix, add 1 ml of Carrez solution No. 2 (4.10) and mix thoroughly. Bring the solution to a temperature of 20 C, dilute to the mark with water. Filter through a fluted filter paper, discarding the fi
49、rst 10 ml of the filtrate. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 16:07:39 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 6 EN 12857:1999 BSI 09-1999 To make allowance for the volume of any precipitate, if the fat-free insoluble matter in the initial sample mass exceeds approximately 3 g, it is advisable to centrifuge the clarified sample mixture for 10 min at a centrifugal acceleration of at least 1 400g before filtering it quantitatively into the 100 ml volumetric flask.
链接地址:https://www.31doc.com/p-3740258.html