EN ISO 10927-2011 en Plastics - Determination of the molecular mass and molecular mass distribution of polymer species by matrix-assisted laser desorption ionization time-of-flight.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 10927:2011Plastics Determinationof the molecular mass andmolecular mass distributionof polymer species by matrix-assisted laser desorption/ionization time-of-flight mas

2、sspectrometry (MALDI-TOF-MS)(ISO 10927:2011)BS EN ISO 10927:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO10927:2011.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/21, Testing of plastics.A list of organizations represe

3、nted on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 65075 8ICS 83.080.01Compliance with a British Standard cannot confer immu

4、nity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 June 2011.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 10927 April 2011 ICS 83.080.01 English Versio

5、n Plastics - Determination of the molecular mass and molecular mass distribution of polymer species by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) (ISO 10927:2011) Plastiques - Dtermination de la masse molculaire et de la distribution des masses molcul

6、aires des polymres par spectromtrie de masse, temps de vol, aprs dsorption/ionisation laser assiste par matrice (SM-MALDI-TOF) (ISO 10927:2011) Kunststoffe - Bestimmung der Molmasse und Molmassenverteilung von polymeren Species durch matrixuntersttze Laser-Desorptions/Ionisations-Flugzeit-Massenspek

7、trometrie (MALDI-TOF-MS) (ISO 10927:2011)This European Standard was approved by CEN on 14 April 2011. 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 alteration. U

8、p-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 language made by tran

9、slation 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, Denmark, Estonia, Finla

10、nd, France, Germany, 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 KO

11、MITEE 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 10927:2011: EBS EN ISO 10927:2011EN ISO 10927:2011 (E) 3 Foreword This document (EN ISO 10927:2011) has

12、been prepared by Technical Committee ISO/TC 61 “Plastics“ in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes” the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by end

13、orsement, at the latest by October 2011, and conflicting national standards shall be withdrawn at the latest by October 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 not be held responsible for ide

14、ntifying 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, Estonia, Finland, France, Ge

15、rmany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 10927:2011 has been approved by CEN as a EN ISO 10927:2011

16、without any modification. BS EN ISO 10927:2011ISO 10927:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Principle .2 5 Reagents 3 5.1 Matrices 3 5.2 Solvents3 5.3 Salts 3 5.4 Molecular mass standards .3 6

17、Apparatus.3 6.1 General .3 6.2 Sample introduction chamber/target.3 6.3 Laser source 4 6.4 Flight tube 4 6.5 Detector 5 6.6 Data recording .5 6.7 Data handling.5 7 Procedure.5 7.1 General .5 7.2 Sample preparation.5 7.3 Instrument settings .6 7.4 Recording spectra.7 8 Data acquisition and processing

18、.8 8.1 General .8 8.2 Calibration8 8.3 Generation of calibration curve .9 8.4 Signal intensity axis calibration.9 9 Expression of results9 9.1 Calculation of molecular mass distribution9 9.2 Calculation of the average molecular masses .9 10 Precision 9 11 Test report10 Annex A (normative) Calibrants

19、 11 Annex B (informative) Precision data .12 Bibliography13 BS EN ISO 10927:2011ISO 10927:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Interna

20、tional Standards is normally 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

21、ISO, also take part in the 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 2. The main task of technical

22、committees is to prepare International Standards. Draft International Standards adopted by the technical 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 t

23、he possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 10927 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-chemical properties. BS EN IS

24、O 10927:2011ISO 10927:2011(E) ISO 2011 All rights reserved vIntroduction The molecular mass and molecular mass distribution of a synthetic polymer are fundamental characteristics that result from the polymerization process. They may be used for a wide variety of correlations for fundamental studies

25、and for processing and product applications. Determination of the molecular mass and molecular mass distribution is used for quality control of polymers and for specification purposes in the commerce of polymers. The comparability of MALDI-TOF-MS results obtained in different laboratories can be ens

26、ured by using standardized conditions of measurement, identical samples and identical matrix preparation methods. The classification of MALDI-TOF-MS as an equitable (standardized) method compared with other established methods of polymer characterization could result in a significant increase in the

27、 use of MALDI-TOF-MS. BS EN ISO 10927:2011BS EN ISO 10927:2011INTERNATIONAL STANDARD ISO 10927:2011(E) ISO 2011 All rights reserved 1Plastics Determination of the molecular mass and molecular mass distribution of polymer species by matrix-assisted laser desorption/ionization time-of-flight mass spec

28、trometry (MALDI-TOF-MS) 1 Scope This International Standard specifies a general method for determining the average molecular mass and molecular mass distribution of polymers (see Reference 1) from 2 000 gmol1to 20 000 gmol1by matrix-assisted laser desorption/ionization time-of-flight mass spectromet

29、ry (MALDI-TOF-MS). The average molecular masses and molecular mass distributions are calculated from a calibration curve constructed using synthetic-polymer and/or biopolymer standards. This method is therefore classified as a relative method. The method is not applicable to polyolefins or to polyme

30、rs with a polydispersity 1,2. 2 Normative references The following referenced documents are indispensable 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) appli

31、es. ISO 472, Plastics Vocabulary 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 472 and the following apply. 3.1 matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry MALDI-TOF-MS a mass-spectrometric technique in which the se

32、paration is based on different flight times in a field free flight tube depending on the mass of formed polymer ions after ionization by a laser, desorption and acceleration by high voltage 3.2 molecular mass M sum of the masses of the atoms making up a molecule NOTE Molecular weight is also used fo

33、r molecular mass. BS EN ISO 10927:2011ISO 10927:2011(E) 2 ISO 2011 All rights reserved3.3 average molecular mass Three possible types of average molecular mass are defined by the following equations, where Niis the number of molecules of species i of molecular mass Mi; miis the mass of the ith speci

34、es (i.e. mi= NiMi); zi= miMi/mi. 3.3.1 number-average molecular mass Mn1n1()iiiiiNMMN=(1) 3.3.2 mass-average molecular mass Mw211w11()()ii iiii iNM mMMNM m=(2) 3.3.3 z-average molecular mass Mz()32111z2111()()ii ii iiii ii iNM mM zMMNM mM z=(3) 4 Principle The MALDI process involves the desorption a

35、nd the ionization of an analyte dispersed in an organic small-molecule matrix. The matrix must be able to absorb the laser energy. A metal salt may be added to cationize the analyte. A polymer is co-crystallized or co-mixed with the matrix molecule and deposited on the target. A short-duration UV la

36、ser pulse is used to desorb the matrix and the analyte. The laser energy is transferred to the matrix molecules, causing them to vaporize. Analyte and matrix molecules leave the target surface in a plume. Due to the very short desorption time, polymer molecules do not degrade. The polymer in the des

37、orption plume gains a cation and is accelerated by a high voltage, drifts down the field-free flight tube and is detected at the end of the flight tube. The time of flight of the species is a measure of its mass. From the distribution of arrival times and the calibration of the arrival times with kn

38、own mass standards, the mass distribution of the polymer is determined. BS EN ISO 10927:2011ISO 10927:2011(E) ISO 2011 All rights reserved 35 Reagents 5.1 Matrices 2,5-dihydroxybenzoic acid (gentisic acid, DHB) and 1,8,9-trihydroxyanthracene (dithranol) are the recommended matrices for this method.

39、All of these materials shall be at least 97 % pure. They shall be stored in a freezer and warmed to room temperature immediately before use. 5.2 Solvents The recommended solvent is tetrahydrofuran (THF). THF with an antioxidant, such as 2,6-di-tert-butyl-4-methylphenol (dibutylated hydroxytoluene, B

40、HT) at a concentration of 0,025 % to 0,1 % (m/V), shall be stored in an amber container. If THF without an antioxidant is used, it shall be stored in an amber container under an inert gas. Otherwise, it will react with oxygen to form peroxides which are hazardous on evaporative concentration. Depend

41、ing on the solubility of the polymer being investigated, toluene, methanol and acetone may also be used. High-purity solvents are recommended. 5.3 Salts Lithium, sodium, potassium and silver trifluoroacetate are recommended since they are soluble in THF and toluene. AgNO3with ethanol as solvent may

42、be used with the polymer and matrix in THF. The salts shall be soluble in the solvent chosen for the polymer and the matrix. When silver nitrate is used, relevant safety aspects should be borne in mind. 5.4 Molecular mass standards The calibration of the mass spectrometer shall be carried out using

43、biopolymers and/or synthetic polymers with known repeating units and end groups. The molecular masses of the standards shall lie within the range of the molecular mass of the polymer being investigated. The software of the mass spectrometer shall be used for calibration. A list of recommended biopol

44、ymers and their molecular masses is given in Annex A. 6 Apparatus 6.1 General A schematic diagram of a MALDI-TOF mass spectrometer is shown in Figure 1. The main components are a sample introduction chamber, a laser source, an ion source, a flight tube with an acceleration region and an ion detector

45、. The instruments may have additionally an ion deflector and a reflector detector. Both commercially available TOF mass spectrometers and systems assembled in the laboratory may be used for this method, provided they meet the required levels of performance. 6.2 Sample introduction chamber/target A M

46、ALDI test sample consists of a film, containing the analyte, the matrix and a salt mixture, deposited as so-called “spots” on a metal plate. The entire plate, with the sample spots, is often referred to as the MALDI target. The MALDI target is introduced into the spectrometer vacuum chamber by eithe

47、r a manual or an automatic operation. The target is moveable, so that all the sample spots on the target are accessible to the laser beam. BS EN ISO 10927:2011ISO 10927:2011(E) 4 ISO 2011 All rights reserved412910768531112Key 1 laser source 2 counter 3 optical system with beam splitter and attenuato

48、r 4 test sample introduction chamber 5 target 6 ion acceleration optics 7 reflector 8 linear detector 9 reflector detector 10 vacuum pump system 11 data recording 12 computer Figure 1 Schematic diagram of a MALDI-TOF mass spectrometer 6.3 Laser source The laser system is comprised of a pulsed laser,

49、 an attenuator which allows the adjustment of the laser power, beam splitters to direct a fraction of the laser light to a photodiode to start the timing for the TOF measurement, and a lens and mirror system to direct the laser beam onto the MALDI target. The wavelength of the laser shall be in the absorption range of the matrix. Typically, UV-lasers are used. 6.4 Flight tube The target is at a high voltage of several kilovolts and situated just behind the acceleration optics. The analyt