1、February 2010 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).IC
2、S 59.140.10!$Gu“1573682www.din.deDDIN EN ISO 27587Leather Chemical tests Determination of the free formaldehyde in process auxiliaries(ISO 27587:2009)English translation of DIN EN ISO 27587:2010-02Leder Chemische Prfungen Bestimmung des Gehaltes an freiem Formaldehyd in Hilfsmitteln fr die Lederhers
3、tellung(ISO 27587:2009)Englische bersetzung von DIN EN ISO 27587:2010-02Cuir Essais chimiques Dosage du formaldhyde libre dans les auxiliaires de traitement (ISO 27587:2009)Traduction anglaise de DIN EN ISO 27587:2010-02www.beuth.deIn case of doubt, the German-language original shall be considered a
4、uthoritative.Document comprises 11 pages02.10 DIN EN ISO 27587:2010-02 2 National foreword This standard has been prepared by Technical Committee CEN/TC 289 “Leather” (Secretariat: UNI, Italy), in collaboration with the International Union of Leather Technologists and Chemists Societies (IULTCS). Th
5、e 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 Standard corresponding to the International Standard referred to in this document is as fol
6、lows: ISO 3696 DIN ISO 3696 National Annex NA (informative) Bibliography DIN ISO 3696, Water for analytical laboratory use Specification and test methods A comma is used as the decimal marker. EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 27587 October 2009 ICS 59.140.30 English Version L
7、eather - Chemical tests - Determination of the free formaldehyde in process auxiliaries (ISO 27587:2009) Cuir - Essais chimiques - Dosage du formaldhyde libre dans les auxiliaires de traitement (ISO 27587:2009) Leder - Chemische Prfverfahren - Bestimmung des Gehalts an freiem Formaldehyd in Hilfsmit
8、teln fr die Lederherstellung (ISO 27587:2009) This European Standard was approved by CEN on 26 September 2009. 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 any alte
9、ration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by tra
10、nslation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germ
11、any, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG
12、 Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 27587:2009: EContents Page 2 DIN EN ISO 27587:2010-02 EN ISO 27587:2009 (E) PageForeword .3 1 Scope4 2 Normative referen
13、ces4 3 Terms and definitions .4 4 Principle .4 5 Reagents 4 6 Apparatus and materials.5 7 Methods6 7.1 Outline of sample preparation system6 7.2 Sample preparation.6 8 HPLC conditions (recommendations).7 9 Calibration7 10 Calculation .7 11 Checking reagents for absence of formaldehyde8 12 Control of
14、 the procedure 8 13 Determination of formaldehyde in stock solutions .8 14 Test report8 Annex A (informative) Reliability of the method9 Foreword 3 EN ISO 27587:2009 (E) DIN EN ISO 27587:2010-02 This document (EN ISO 27587:2009) has been prepared by Technical Committee CEN/TC 289 “Leather”, the secr
15、etariat of which is held by UNI, in collaboration with the International Union of Leather Technologists and Chemists Societies (IULTCS). This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2010,
16、 and conflicting national standards shall be withdrawn at the latest by April 2010. 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 not be held responsible for identifying any or all such patent rights. Ac
17、cording to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, La
18、tvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. 1 Scope This International Standard specifies a method for the determination of free formaldehyde in process auxiliaries for leather. The analyti
19、cal result obtained according to this procedure is expressed in milligrams per kilogram (mg/kg) sample. The upper limit of quantification of the method is given by the capacity of the cartridge (total carbonyls 6 400 g/cartridge). 2 Normative references The following referenced documents are indispe
20、nsable 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 3696, Water for analytical laboratory use Specification and test methods 3 Terms and defini
21、tions For the purposes of this document, the following terms and definitions apply. 3.1 free formaldehyde formaldehyde that is released under dynamic conditions when the sample is heated in an inert dry atmosphere 4 Principle The sample is heated in an inert atmosphere for a defined period of time.
22、The released formaldehyde is captured and derivatized using a dinitrophenylhydrazine (DNPH) cartridge. The analyte is eluted with acetonitrile and analysed by high-performance liquid chromatography (HPLC) using a UV detector. 5 Reagents Use only reagents of recognized analytical grade, unless otherw
23、ise stated. 5.1 Sulfuric acid, 3 mol/l. 5.2 Sodium hydroxide, 2 mol/l. 5.3 Sodium thiosulfate, 0,1 mol/l. 5.4 Iodine solution, 0,05 mol/l, i.e. 12,68 g iodine per litre of water. 4 DIN EN ISO 27587:2010-02 EN ISO 27587:2009 (E) 5.5 Starch solution, 1 g/100 ml water. 5.6 Formaldehyde hydrazone soluti
24、on. 5.7 Calibration standards. Prepare solutions by adequate dilution of the formaldehyde hydrazone solution (5.6). 5.8 Formaldehyde solution, approximately 37 % mass fraction. 5.9 Formaldehyde stock solution S1, prepare by pipetting 5 ml of formaldehyde solution (5.8) in a 1 000 ml volumetric flask
25、 and fill to the mark with distilled water. 5.10 Formaldehyde solution S2 in an adequate dilution for procedure control e.g. 2,5 ml of the formaldehyde stock solution S1 (5.9) in a 100 ml volumetric flask, fill up with distilled water. The concentration of this solution should be adapted to ensure t
26、hat the formaldehyde content is in the middle of the calibrated range. 5.11 Distilled water, quality 2 according to ISO 3696. 5.12 2,4-Dinitrophenylhydrazine cartridges (DNPH cartridges), suitable for fixing a total of 6 400 g of carbonyls per cartridge. For lower quantities of free formaldehyde, a
27、smaller capacity cartridge can be used. It is recommended that the cartridge have an excess capacity of at least 20 % more than the predicted formaldehyde amount. 5.13 Acetonitrile, HPLC grade. 5.14 Water, HPLC grade. 6 Apparatus and materials Usual laboratory apparatus is required and, in particula
28、r, the following. 6.1 Thermostatic oil bath with stirring facilities, capable of maintaining a constant temperature of (90 3) C. The oil bath shall be deep enough to allow the U-tube to be dipped in up to the side tubing. 6.2 Silicone oil, suitable for oil bath (6.1). 6.3 Nitrogen, purity 4,6. 6.4 U
29、-tube, calcium chloride tube, U-shaped, with two stopcocks, leg length 150 mm. 6.5 Flow meter. 6.6 Silicone tubing. 6.7 Syringe filters, 0,45 m, regenerated cellulose. 6.8 Sea sand, purified by acid and calcined; quality grade GR for analysis. 6.9 Polytetrafluoroethylene (PTFE) stopcock grease, free
30、 of formaldehyde. 6.10 HPLC equipped with a UV detector. 6.11 HPLC column, of the RP-C18 type. 6.12 Hair dryer. 5 EN ISO 27587:2009 (E) DIN EN ISO 27587:2010-02 7 Methods 7.1 Outline of sample preparation system See Figure 1. Key 1 gas tank 2 flow meter 3 DNPH cartridge 4 HPLC Figure 1 Schematic out
31、line of sample preparation system 7.2 Sample preparation Prepare a sample preparation system as described in 7.1. Initially, the U-tube (6.4) and the DNPH cartridge (5.12) are disconnected from the sampling system. All the parts of the sample preparation system shall be dry prior to use. Purge the s
32、ystem for 15 min with nitrogen (6.3) at a flow rate of 500 ml/min. It is important that the analysis be carried out under an inert atmosphere. The purging step may be omitted before further analyses if work is done without interruption. The sampling system is slightly pressurized; therefore, all sto
33、pcocks should be secured with joint clamps. Add 3 g to 4 g of sea sand (6.8) to the U-tube (6.4), ensuring that it is not blocked and that the nitrogen flow can be maintained. If this is not possible, use a larger diameter U-tube. Accurately weigh 0,5 g to 2 g of sample to the nearest 0,001 g into t
34、he U-tube. It may be necessary to reduce the amount of sample if it is in a liquid phase in order to diminish the likelihood of condensed water giving erroneous results. Apply a thin layer of stopcock grease (6.9) to the joints of the U-tube. Introduce the U-tube into the system and purge for 5 min
35、with nitrogen (6.3) at a flow rate of 500 ml/min. Reduce the flow rate to between 150 ml/min to 350 ml/min. Introduce the DNPH cartridge (5.12) into the system and place the U-tube into the oil bath (6.1) preheated to 90 C. Cover the cartridge and U-tube carefully with aluminum foil. During sampling
36、, it may be necessary to readjust the flow rate. After 30 min, remove the U-tube containing the sample from the oil bath. Remove any condensate from the cartridge side of the tubing and stopcock using a hair dryer (6.12). This step shall be carried out irrespective of whether condensate can be obser
37、ved visually. 6 DIN EN ISO 27587:2010-02 EN ISO 27587:2009 (E) Remove the DNPH cartridge from the system and elute with small portions of acetonitrile (5.13) in a 10 ml volumetric flask. Make up to volume with acetonitrile. Carefully mix the solution by shaking and filter an aliquot for analysis usi
38、ng a syringe filter (6.7). Analyse the resulting filtrate by HPLC (6.10). It is recommended that the cartridges be removed from the refrigerator immediately prior to use. Experiments have shown that cartridges should be eluted within 3 days. 8 HPLC conditions (recommendations) Separation column: CC
39、250/4 Nucleosil 100-5 C18 HD1)with pre-column Flow rate: 0,8 ml/min Mobile phase: Solvent A, water Solvent B, acetonitrile Gradient: 55 % B linear to 95 % B in 20 min Column oven: 30 C UV detection: 360 nm Injection volume: 20 l 9 Calibration Calibration is carried out by means of an external standa
40、rd in the range of 0,5 g/10 ml to 50 g/10 ml. The working range is limited by the capacity of the cartridge. Prepare adequate dilutions (in acetonitrile) of the formaldehyde hydrazone solution (5.6). Calibration shall be done using at least six concentration levels. The calibration is effected throu
41、gh plotting a graph of the formaldehyde derivative peak area versus the concentration (g/10 ml). 10 Calculation Calculate the formaldehyde content (w) expressed in milligrams per kilogram (mg/kg) of sample being tested. Fwm=where is the concentration of formaldehyde obtained from the calibration gra
42、ph, expressed in g/10 ml; F is the dilution factor; m is the mass of the sample, expressed in grams (g).1) Nucleosil 100-5 C18 HD is the trade name of a product supplied by Sorbent Technologies. This information is given for the convenience of users of this document and does not constitute an endors
43、ement by ISO of the product named. Equivalent products may be used if they can be shown to lead to the same results. 7 EN ISO 27587:2009 (E) DIN EN ISO 27587:2010-02 11 Checking reagents for absence of formaldehyde Blank analyses should be carried out on a regular basis and at least for each lot of
44、reagents, mobile phase and cartridges or any other change in the system. The formaldehyde content detected in the blank solution should be below 75 % of the lowest calibration level (0,5 g/10 ml). 12 Control of the procedure Spike the sea sand within the U-tube with 250 l of formaldehyde solution S2
45、 (5.10). Proceed as described in 7.2. Calculations are carried out as described in Clause 10. A minimum recovery rate of 90 % shall be calculated. In the event of lower levels being detected, possible sources of error shall be detected and eliminated prior to routine analysis of samples. 13 Determin
46、ation of formaldehyde in stock solutions Pipette 10 ml of formaldehyde stock solution S1 (5.9) into a 250 ml Erlenmeyer flask and mix with 50 ml of iodine solution (5.4) as well as with sodium hydroxide (5.2) until it turns to yellow. Allow it to settle for 15 min at 18 C to 30 C and then add 15 ml
47、sulfuric acid (5.1) while swirling. After adding 2 ml of starch solution (5.5), titrate the excess iodine with sodium thiosulfate (5.3) until the colour changes. Make three individual determinations. Titrate a blank solution in the same manner. 01ThFAS()2VVc M= where S is the concentration of the fo
48、rmaldehyde stock solution S1, in mg/10 ml; V0is the titre volume of the thiosulfate solution for the blank solution, in ml; V1is the titre volume of the thiosulfate solution for the sample solution, in ml; cThis the concentration of the thiosulfate solution, in mol/l; MFAis the relative molecular ma
49、ss of formaldehyde, 30,02 g/mol. 14 Test report The test report shall include the following: a) a reference to this International Standard (ISO 27587); b) the type, origin and designation of the analysed product and the sampling method used; c) the analytical result for free formaldehyde content in milligrams per kilogram (mg/kg), rounded to one decimal place; d) any deviation from the analytical procedure; e) the date of the test. 8 DIN EN ISO 27587:2010-02 EN ISO 27587:2009 (E) Annex A (informative) Reliability of the method
