1、July 2017 English price group 11No 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 67.160.20; 67.230!%gg0“2686813www.d
2、in.deDIN EN 16857Foodstuffs Determination of benzene in soft drinks, other beverages and vegetablebased infant foods by headspace gas chromatography mass spectrometry (HSGCMS);English version EN 16857:2017,English translation of DIN EN 16857:2017-07Lebensmittel Bestimmung von Benzol in Erfrischungsg
3、etrnken, anderen Getrnken und in Babynahrung auf Gemsebasis mit HeadspaceGaschromatographie/Massenspektrometrie (HSGCMS);Englische Fassung EN 16857:2017,Englische bersetzung von DIN EN 16857:2017-07Produits alimentaires Dtermination de la teneur en benzne dans les boissons non alcoolises, les autres
4、 boissons et les aliments pour nourrissons base de lgumes par chromatographie en phase gazeuse avec espace de tte couple la spectromtrie de masse (HSCGSM);Version anglaise EN 16857:2017,Traduction anglaise de DIN EN 16857:2017-07www.beuth.deDocument comprises 17 pagesDTranslation by DIN-Sprachendien
5、st.In case of doubt, the German-language original shall be considered authoritative.06.17 DIN EN 16857:2017-07 2 A comma is used as the decimal marker. National foreword This document (EN 16857:2017) has been prepared by Technical Committee CEN/TC 275 “Food analysis Horizontal methods” (Secretariat:
6、 DIN, Germany). The responsible German body involved in its preparation was DIN-Normenausschuss Lebensmittel und landwirtschaftliche Produkte (DIN Standards Committee Food and Agricultural Products), Working Committee NA 057-01-14 AA “Process contaminants”. The DIN Standards corresponding to the Int
7、ernational Standards referred to in this document are as follows: ISO/IEC 17025 DIN EN ISO/IEC 17025 ISO 5725-2:1994 DIN ISO 5725-2:2002-12 National Annex NA (informative) Bibliography DIN EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories DIN ISO 5725-
8、2:2002-12, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method (ISO 5725-2:1994 including Technical Corrigendum 1:2002) EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM
9、EN 16857 May 2017 ICS 67.160.20; 67.230 English Version Foodstuffs - Determination of benzene in soft drinks, other beverages and vegetable-based infant foods by headspace gas chromatography mass spectrometry (HS-GC-MS) Produits alimentaires - Dtermination de la teneur en benzne dans les boissons no
10、n alcoolises, les autres boissons et les aliments pour nourrissons base de lgumes par chromatographie en phase gazeuse avec espace de tte couple la spectromtrie de masse(HS-CG-SM)Lebensmittel - Bestimmung von Benzol in Erfrischungsgetrnken, anderen Getrnken und in Babynahrung auf Gemsebasis mit Head
11、space-Gaschromatographie/Massenspektrometrie(HS-GC-MS) This European Standard was approved by CEN on 20 February 2017. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without
12、any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other lang
13、uage made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmar
14、k, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COM
15、MITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16857:2017 EEN 16857:201
16、7 (E) 2 Contents Page European foreword . 3 1 Scope 4 2 Normative references 4 3 Principle . 4 4 Reagents . 4 5 Apparatus . 6 6 Procedure. 8 7 HS-GC-MS analysis . 8 8 Calculation 11 9 Precision data 11 10 Test report 12 Annex A (informative) Typical chromatograms 13 Annex B (informative) Precision d
17、ata . 14 Bibliography . 15 DIN EN 16857:2017-07 EN 16857:2017 (E) 3 European foreword This document (EN 16857:2017) 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
18、 national standard, either by publication of an identical text or by endorsement, at the latest by November 2017, and conflicting national standards shall be withdrawn at the latest by November 2017. Attention is drawn to the possibility that some of the elements of this document may be the subject
19、of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the Europan Free Trade Association. WARNING The use of this standard can involve hazardous materials, operati
20、ons and equipment. This standard does not purport to address all the safety problems associated with its use. It is the responsibility of the user of this standard to take appropriate measures for ensuring the safety and health of the personnel prior to application of the standard and to fulfil stat
21、utory requirements for this purpose. Benzene has been classified by IARC as carcinogenic to humans (see 1). According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cr
22、oatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Tu
23、rkey and the United Kingdom. DIN EN 16857:2017-07 EN 16857:2017 (E) 4 1 Scope This European Standard specifies a method for the determination of benzene in soft drinks, other beverages and vegetable-based infant foods, by headspace gas chromatography mass spectrometry (HS-GC-MS). The method has been
24、 validated in an interlaboratory study via the analysis of spiked samples of carbonated soft drink, still fruit-based drink, carbonated fruit-based drink, vegetable and fruit juice containing carrot, infant food vegetable based and infant food containing meat, ranging from 1,9 g/kg to 18,6 g/kg. How
25、ever, linearity of the instrument response was proven for the concentration range from 0,5 g/kg to 20 g/kg. The limit of quantification (LOQ) depends on the instrument but can generally be expected to be in the range from 0,5 g/kg to 1,0 g/kg. 2 Normative references The following documents, in whole
26、 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 references, the latest edition of the referenced document (including any amendments) applies. EN ISO 3696:1995, Water for analytical l
27、aboratory use - Specification and test methods (ISO 3696:1987) 3 Principle The sample is homogenized, a test portion is heated in a closed system with isotopically-labelled benzene added as internal standard. A portion of the headspace is injected into a GC-MS system for identification and quantific
28、ation. The injection is performed with a split-splitless injection port. The chromatographic separation is obtained on a mid-polarity capillary GC column. The benzene is ionized at 70 eV, recorded in selected ion monitoring (SIM) mode, and quantified by comparison with the stable isotope labelled an
29、alogue. 4 Reagents Use only reagents of recognized analytical grade and water complying with grade 1 of EN ISO 3696:1995, unless otherwise specified. Prepare standard solutions preferably gravimetrically. Use an analytical balance (5.1) for the preparation of both native and stable isotope labelled
30、benzene standard solutions. 4.1 Benzene, C6H6, purity is 99,0 % (CAS 71-43-2). While not necessary, it is recommended to store at 4 C to 6 C to prevent evaporation. Bring to room temperature before use. 4.2 Benzene-d6, purity is 99, 6 atom % D (CAS 1076-43-3). While not necessary, it is recommended
31、to store at 4 C to 6 C to prevent evaporation. Bring to room temperature before use. 4.3 Helium purified compressed gas, purity equivalent to 99,995 % or better. 4.4 Methanol, suitable for headspace GC analysis (CAS 67-56-1). 4.5 Preparation of stock and standard solutions 4.5.1 General Prepare all
32、standard solutions preferably gravimetrically. Record the tare masses of all recipients and the masses after each preparation step and use for calculation of the mass concentrations of standard solutions. DIN EN 16857:2017-07 EN 16857:2017 (E) 5 Volumetric preparation of standard solutions may also
33、be applied provided that the volumetric glassware used complies with EN ISO 1042 (see 2). 4.5.2 Benzene stock solution, mass concentration approximately 2,20 mg/ml Pipette 20 ml 0,1 ml of methanol into a 20 ml headspace vial (5.17) and seal the vial with a crimp cap. Weigh the sealed vial to the nea
34、rest 0,1 mg and record the weight as W1. Using a microsyringe, transfer 50 l of benzene (4.1) through the septum of the vial containing the methanol and shake vigorously or vortex to mix. Reweigh the sealed vial and record the weight (W2) to the nearest 0,1 mg. Subtract W1from W2to determine the wei
35、ght of benzene transferred (W3). Calculate the mass concentration of stock solution from W3divided by the total volume (20,05 ml). Alternatively, commercially available certified standard solutions may be used if available. Store the benzene stock solution at 4 C to 6 C but allow it to attain ambien
36、t temperature before use. Discard after 2 weeks. Once the septum on the stock solution has been pierced, the cap shall be replaced. 4.5.3 Benzene intermediate standard solution, approximately 54 g/ml Using a microsyringe, transfer 500 l of benzene stock solution (4.5.2) to a sealed headspace vial co
37、ntaining 20 ml 0,1 ml of methanol and shake vigorously. Prepare fresh daily. Calculate the exact mass concentration from the stock solution (4.5.2). 4.5.4 Benzene standard solution, approximately 0,5 g/ml Using a microsyringe, transfer 200 l of benzene intermediate standard solution (4.5.3) to a sea
38、led headspace vial containing 20 ml 0,1 ml of water and shake vigorously. Prepare fresh daily. Calculate the exact concentration from the stock solution (4.5.2). Use this standard solution to prepare a 6-point calibration from 0,5 g/kg to 20 g/kg (see 4.6). 4.5.5 Benzene-d6internal standard (IS) sto
39、ck solution, approximately 2,36 mg/ml Pipette 20 ml 0,1 ml of methanol into a 20 ml headspace vial (5.17) and seal the vial with a crimp cap. Weigh the sealed vial to the nearest 0,1 mg and record the weight as W1. Using a microsyringe, transfer 50 l of benzene-d6(4.2) through the septum of the vial
40、 containing the methanol and shake vigorously or vortex. Reweigh the sealed vial and record the weight (W2) to the nearest 0,1 mg. Subtract W1from W2to determine the weight of benzene-d6transferred (W3). Calculate the mass concentration of IS stock solution from W3divided by the total volume (20,05
41、ml). Alternatively, commercially available certified standard solutions may be used if available. Store the benzene-d6IS stock solution at 4 C to 6 C but allow it to attain ambient temperature before use. Discard after 2 weeks. Once the septum on the IS stock solution has been pierced, the cap shall
42、 be replaced. 4.5.6 Benzene-d6internal standard (IS) solution, approximately 4,2 g/ml Using a microsyringe, transfer 36 l of benzene-d6IS stock solution (4.5.5) to a sealed headspace vial containing 20 ml 0,1 ml of water and shake vigorously. Prepare fresh daily. Calculate the exact mass concentrati
43、on from the benzene-d6IS stock solution (4.5.5). 4.6 Preparation of the calibration solutions Prepare calibration solutions of approximately 0 g/kg, 0,5 g/kg, 1 g/kg, 2,5 g/kg, 5 g/kg, 10 g/kg and 20 g/kg benzene and approximately 10 g/kg IS according to the following scheme. Add 10 g 0,05 g of wate
44、r to each of seven 20 ml headspace vials and transfer using a positive displacement pipette benzene standard solution (4.5.4), IS solution (4.5.6)and water according to the values given in Table 1. To avoid loss of benzene, seal the vials immediately following addition of the entire benzene and benz
45、ene-d6solutions and water. DIN EN 16857:2017-07 EN 16857:2017 (E) 6 Table 1 Preparation of calibration solutions Mass of water g Volume of 0,5 g/ml benzene (4.5.4) l Volume of 4,2 g/ml benzene-d6(4.5.6) l Volume of water l Benzene mass concentration g/kg Benzene d6mass concentration g/kg 10 0 25 400
46、 0 10,1 10 10 25 390 0,5 10,1 10 20 25 380 1,0 10,1 10 50 25 350 2,5 10,1 10 100 25 300 5,0 10,1 10 200 25 200 10 10,1 10 400 25 0 20 10,1 5 Apparatus WARNING All glassware shall be meticulously cleaned (except disposable glassware). Usual laboratory glassware and equipment and, in particular, the f
47、ollowing: 5.1 Analytical balance, capable of weighing to the nearest of 0,0 001 g. 5.2 Top pan balance, capable of weighing to the nearest 0,001 g. 5.3 Headspace gas chromatography mass spectrometry (HS-GC-MS) apparatus, comprising the following: 5.3.1 Headspace sampling and injection system, suitab
48、le for incubation temperatures of up to 60 C and incubation time of 30 min. The headspace sampling needle should be suitable for maintenance at 100 C and the transfer line at 105 C. DIN EN 16857:2017-07 EN 16857:2017 (E) 7 5.3.2 Injection system, split-splitless injector, suitable for temperatures u
49、p to 250 C. A programmed temperature vaporizing (PTV) injector may be used as an alternative to a split/splitless injector. However, split/splitless injection was proven in the method validation study by collaborative trial suitable for the scope of this standard. 5.4 GC oven, suitable for temperatures up to 240 C and capable of temperature programming. 5.5 Sample carousel, suitabl
