1、September 2011 Translation by DIN-Sprachendienst.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).I
2、CS 59.140.30!$tJn“1813975www.din.deDDIN EN ISO 17226-3Leather Chemical determination of formaldehyde content Part 3: Determination of formaldehyde emissions from leather(ISO 17226-3:2011)English translation of DIN EN ISO 17226-3:2011-09Leder Chemische Bestimmung des Formaldehydgehalts Teil 3: Bestim
3、mung der Formaldehydemissionen aus Leder (ISO 17226-3:2011)Englische bersetzung von DIN EN ISO 17226-3:2011-09Cuir Dosage chimique du formaldhyde Partie 3: Dosage du formaldhyde mis par le cuir (ISO 17226-3:2011)Traduction anglaise de DIN EN ISO 17226-3:2011-09www.beuth.deDocument comprises pagesIn
4、case of doubt, the German-language original shall be considered authoritative.1208.11 DIN EN ISO 17226-3:2011-09 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 289 “Leather” (Secretariat: UNI, Italy) in collaboration with the
5、International Union of Leather Technologists and Chemists Societies. The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Working Committee NA 062-05-52 AA Chemische Prfverfahren fr Leder. The DIN Standards correspond
6、ing to the International Standards referred to in this document are as follows: ISO 2418 DIN EN ISO 2418 ISO 2419 DIN EN ISO 2419 ISO 3696 DIN ISO 3696 ISO 4684 DIN EN ISO 4684 National Annex NA (informative) Bibliography DIN EN ISO 2418, Leather Chemical, physical and mechanical and fastness tests
7、Sampling location DIN EN ISO 2419, Leather Physical and mechanical tests Sample preparation and conditioning DIN EN ISO 4684, Leather Chemical tests Determination of volatile matter DIN ISO 3696, Water for analytical laboratory use Specification and test methods EUROPEAN STANDARD NORME EUROPENNE EUR
8、OPISCHE NORM EN ISO 17226-3 May 2011 ICS 59.140.30 English Version Leather - Chemical determination of formaldehyde content - Part 3: Determination of formaldehyde emissions from leather (ISO 17226-3:2011) Cuir - Dosage chimique du formaldhyde - Partie 3: Dosage du formaldhyde mis par le cuir (ISO 1
9、7226-3:2011) Leder - Chemische Bestimmung des Formaldehydgehalts -Teil 3: Bestimmung der Formaldehydemissionen aus Leder (ISO 17226-3:2011) This European Standard was approved by CEN on 11 May 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditi
10、ons 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 CEN-CENELEC Management Centre or to any CEN member. This European Standard exists i
11、n three 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 CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standar
12、ds bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and Uni
13、ted Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 17226-3
14、:2011: EContents DIN EN ISO 17226-3:2011-09 EN ISO 17226-3:2011 (E) 2 Page Foreword3 1 Scope 4 2 Normative references 4 3 Principle4 4 Reagents.4 4.1 Reagents for the formaldehyde stock solution 4 4.2 Reagents for the HPLC method5 5 Apparatus .5 6 Methods 5 6.1 Procedure for the determination of for
15、maldehyde in the stock solution.5 6.1.1 Preparation of the formaldehyde stock solution5 6.1.2 Determination.6 6.2 Procedure for the determination of formaldehyde emission by the HPLC method .7 6.2.1 Shipment and storage leather for this method.7 6.2.2 Sampling.7 6.2.3 Determination of volatile matte
16、r.7 6.2.4 Determination of formaldehyde emission.7 6.2.5 Reaction with DNPH 7 6.2.6 HPLC conditions (recommendations) .7 6.2.7 Calibration of HPLC.8 6.2.8 Calculation of the formaldehyde content in leather samples .8 7 Expression of results 8 8 Test report 9 Foreword This document (EN ISO 17226-3:20
17、11) has been prepared by Technical Committee CEN/TC 289 “Leather”, the secretariat of which is held by UNI, in collaboration with the International Union of Leather Technologists and Chemists Societies. This European Standard shall be given the status of a national standard, either by publication of
18、 an identical text or by endorsement, at the latest by November 2011, and conflicting national standards shall be withdrawn at the latest by November 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall n
19、ot be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark
20、, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN ISO 17226-3:2011-09 EN ISO 17226-3:2011 (E) 3 1 Scope Thi
21、s part of ISO 17226 specifies a method for determining the emission of formaldehyde from leathers. This method is based on high performance liquid chromatography (HPLC). It is selective and also allows the emission of other low molecular aldehydes and ketones to be observed. This part of ISO 17226 d
22、eals with the release of formaldehyde to the gas phase. Therefore, the obtained results are not comparable with the results of methods described in ISO 17726-1 and ISO 17226-2 which are based on extraction with liquid water. 2 Normative references The following referenced documents are indispensable
23、 for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 2418, Leather Chemical, physical and mechanical and fastness tests Sampling location ISO 2419, Le
24、ather Physical and mechanical tests Sample preparation and conditioning ISO 3696:1987, Water for analytical laboratory use Specification and test methods ISO 4684, Leather Chemical tests Determination of volatile matter 3 Principle A specimen with defined dimensions is held above demineralized water
25、 in a sealed bottle and is heated at constant temperature for a specific period. Afterwards, the bottle is cooled and the formaldehyde absorbed into the water is analysed. The water is mixed with 2,4-dinitrophenylhydrazine, whereby aldehydes and ketones react to give the respective hydrazones. These
26、 are separated by means of a reversed-phase HPLC method, detected at 360 nm and quantified. 4 Reagents Use only reagents of recognized analytical grade, unless otherwise stated. The water shall be of grade 3 in accordance with ISO 3696:1987. All solutions are aqueous solutions. 4.1 Reagents for the
27、formaldehyde stock solution 4.1.1 Formaldehyde solution, approximately 37 % (mass fraction). DIN EN ISO 17226-3:2011-09 EN ISO 17226-3:2011 (E) 4 4.1.2 Iodine solution, 0,05 mol/l, i.e. 12,68 g iodine/l. 4.1.3 Sodium hydroxide solution, 2,0 mol/l. 4.1.4 Sulfuric acid solution, 2,0 mol/l. 4.1.5 Sodiu
28、m thiosulfate solution, 0,1 mol/l. 4.1.6 Starch solution, 1 %, i.e. 1 g in 100 ml water. 4.2 Reagents for the HPLC method 4.2.1 Dinitrophenylhydrazine (DNPH) solution, consisting of 0,3 g DNPH (2,4-dinitrophenylhydrazine) dissolved in 100 ml concentrated o-phosphoric acid (85 % mass fraction); (DNPH
29、 recrystallized from 25 % mass fraction, acetonitrile in water). 4.2.2 Acetonitrile. 5 Apparatus Use usual laboratory equipment and, in particular, the following. 5.1 One (1) l polyethylene bottle with hook implement integrated in the lid (see Figure 1). Hook made of stainless steel with seals, posi
30、tioned inside the lid of the test bottle. 5.2 Volumetric flasks, of capacities 10 ml, 500 ml and 1 000 ml. 5.3 Erlenmeyer flasks, of capacities 100 ml and 250 ml. 5.4 Pipettes, of capacities 5 ml and 50 ml. 5.5 Oven, capable of being maintained at (60 2) C. 5.6 Analytical balance, weighing to an acc
31、uracy of 1 mg. 5.7 HPLC system with UV detection, e.g. 360 nm. 5.8 Press knife, in accordance with ISO 2419, suitable for cutting specimens of (100 40) mm. 5.9 Hole punch for holes of 3 mm to 4 mm in diameter. 5.10 Membrane filter, polyamide, 0,45 m. 6 Methods 6.1 Procedure for the determination of
32、formaldehyde in the stock solution 6.1.1 Preparation of the formaldehyde stock solution Pipette 5 ml of the formaldehyde solution (4.1.1) into a 1 000 ml volumetric flask (5.2) which contains approximately 100 ml water, then fill the flask with demineralized water up to the mark. This solution is th
33、e formaldehyde stock solution. DIN EN ISO 17226-3:2011-09 EN ISO 17226-3:2011 (E) 5 Dimensions in millimetres Key 1 polyethylene bottle 2 sample 3 water Figure 1 Polyethylene bottle with specimen and water 6.1.2 Determination Pipette 10 ml from this solution into a 250 ml Erlenmeyer flask (5.3) and
34、mix with the 50 ml iodine solution (4.1.2). Add sodium hydroxide (4.1.3) until it turns yellow. Allow it to react for 15 min 1 min at a temperature between 18 C and 26 C, then add 15 ml of sulfuric acid (4.1.4) while swirling. After adding 2 ml of starch solution (4.1.6), titrate the excess iodine w
35、ith sodium thiosulfate (4.1.5) until the colour changes. Make three individual determinations. Titrate at least two blank solutions in the same manner. 011 FAFA()2VV cM= (1) where FAis the concentration of the formaldehyde stock solution, in milligrams per 10 ml (mg/10 ml); V0is the volume of the th
36、iosulfate solution for the blank solution, in millilitres (ml); V1is the volume of the thiosulfate solution for the sample solution, in millilitres (ml); MFAis the relative molecular mass of formaldehyde, 30,02 g/mol; c1is the concentration of the thiosulfate solution, in moles per litre (mol/l). DI
37、N EN ISO 17226-3:2011-09 EN ISO 17226-3:2011 (E) 6 6.2 Procedure for the determination of formaldehyde emission by the HPLC method 6.2.1 Shipment and storage leather for this method To avoid cross-contamination and loss of formaldehyde during shipment and storage, the leather samples should be seale
38、d in an inert gastight plastic bag. NOTE Multiple-layer polyethylene bags with a metal layer inside are appropriate. 6.2.2 Sampling Sample six specimens of (100 40) mm, selecting them in accordance with ISO 2418 and applying the press knife (5.8) in accordance with ISO 2419. Use five of these specim
39、ens for the determination of formaldehyde emission. Use the sixth specimen for the determination of volatile matter. To fasten specimens 1 to 5, punch a hole of 3 mm to 4 mm near the centre and 10 mm from the upper edge in each one. 6.2.3 Determination of volatile matter If requested to calculate th
40、e result on the basis of dry substance, use the sixth specimen to determine the volatile matter in accordance with ISO 4684. Do not grind or cut the specimen. 6.2.4 Determination of formaldehyde emission Weigh five of the specimens to 0,01 g. Pipette 50 ml aliquots of demineralized water into each o
41、f the 1 l polyethylene bottles which have to be clean and dry. Attach a specimen to each hook and seal the 5 bottles. Pipette 50 ml aliquots of demineralized water into an additional clean 1 l polyethylene bottle. Seal the bottle without a specimen. Use this bottle for a blank test. As soon as the b
42、ottles have been sealed, store them for (180 15) min in a heated oven at (60 2) C. Remove the bottles from the oven and allow them to cool at room temperature for approximately 1 h. Then remove the leather specimens from the bottles and immediately analyse the formaldehyde absorbed in the water as d
43、escribed in 6.2.5. 6.2.5 Reaction with DNPH Pipette 4,0 ml of acetonitrile (4.2.2), a 5,0 ml aliquot of water from the polyethylene bottle (5.1) and 0,5 ml of DNPH solution (4.2.1) into a 10 ml volumetric flask (5.2). Fill the volumetric flask with demineralized water up to the mark and shake it bri
44、efly by hand to mix the components. Allow it to stand at least 60 min, but not more than 180 min. After filtering through a membrane filter (5.10), analyse the sample using HPLC. If the concentration is out of the calibration range, take smaller aliquots. 6.2.6 HPLC conditions These conditions are o
45、nly recommendations. The method used should be verified using the recovery rate determination. The chromatographic system should be checked every day, preferably using a sample containing 2 mg formaldehyde/l, in order to determine the recovery rate. The content of the sample should be determined acc
46、ording the procedure described for the calibration. DIN EN ISO 17226-3:2011-09 EN ISO 17226-3:2011 (E) 7 Flow rate: 1,0 ml/min Mobile phase: acetonitrile/water, 60:40 Separation column: C18 reversed-phase column with precolumn (1 cm, RP18) UV detection wavelength: 360 nm Injection volume: 20 l 6.2.7
47、 Calibration of HPLC Pipette 0,5 ml of the formaldehyde stock solution obtained in 6.1.1, with an exactly known formaldehyde content, into a 500 ml volumetric flask (5.2), pre-filled with approximately 100 ml water. Mix together and fill to the mark with water, and mix again. This solution is the st
48、andard solution for calibration purposes, i.e. the standard solution is approximately 2 g formaldehyde/ml. In each of six 10 ml volumetric flasks (5.2), add 4 ml acetonitrile (4.2.2), then add a concentration series of 0,25 ml; 0,5 ml; 1,0 ml; 2,0 ml; 3,0 ml; 5,0 ml, respectively, of the standard so
49、lution. Immediately after adding the formaldehyde solution, mix each flask and add 0,5 ml DNPH solution (4.2.1). Fill the flasks up to the mark with demineralized water and mix. After at least 60 min, but not more than 180 min, analyse the samples using HPLC after filtration through a membrane filter (5.10). Effect the calibration through plotting a graph of the formaldehyde derivative peak area versus the concentration in g/10 ml. 6.2.8 Calculation of the formaldehyde content in leather samples sample blankFA(
