1、BRITISH STANDARD BS ISO 13741-1:1998 Plastics/rubber Polymer dispersions and rubber latices (natural and synthetic) Determination of residual monomers and other organic components by capillary-column gas chromatography Part 1: Direct liquid injection method ICS 83.040.10; 83.080.01BSISO 13741-1:1998
2、 This British Standard, having been prepared under the directionof the Sector Board forMaterials and Chemicals, waspublished under the authorityof the Standards Boardand comes intoeffect on 15 June 1998 BSI 04-1999 ISBN 0 580 29967 8 National foreword This British Standard reproduces verbatim ISO137
3、41-1:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee PRI/21, Testing of plastics, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any en
4、quiries 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 represented on this committee can be obtained on request to its secretary. Cross-references The B
5、ritish 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 Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A Bri
6、tish 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 itself confer immunity from legal obligations. Summary of pages This document comprises a fro
7、nt cover, an inside front cover, pages i and ii, theISO title page, pagesii toiv, pages1 to5 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued sinc
8、e publication Amd. No. Date CommentsBSISO13741-1:1998 BSI 04-1999 i Contents Page National foreword Inside front cover Foreword iii Test of ISO13741-1 1ii blankBS ISO 13741-1:1998 ii BSI04-1999 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative reference 1 3 Principle 1 4 Reagents 1 5 A
9、pparatus 1 6 Preparation of apparatus 2 7 Calibration 3 8 Procedure 3 9 Calculation 4 10 Precision 4 11 Test report 4 Figure 1 Typical chromatogram 5 Table 1 Typical operating conditions 2BS ISO 13741-1:1998 BSI 04-1999 iii Foreword ISO (the International Organization for Standardization) is a world
10、wide federation of national standards bodies (ISO member bodies). The work of preparing International 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 t
11、hat committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted
12、by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO13741-1 was prepared by Technical Committee ISO/TC61, Plastics, Subcommittee SC9, Therm
13、oplastic materials, in close collaboration with ISO/TC45, Rubber and rubber products. ISO13741 consists of the following parts, under the general title Plastics/rubber Polymer dispersions and rubber latices (natural and synthetic) Determination of residual monomers and other organic components by ca
14、pillary-column gas chromatography. Part1: Direct liquid injection method; Part2: Headspace method. Descriptors: Plastics, polymers, rubber, latex, aqueous dispersions, chemical analysis, determination of content, organic compounds, monomers, gas chromatography, capillary columns.iv blankBS ISO 13741
15、-1:1998 BSI 04-1999 1 Introduction The requirements imposed today by authorities include the assessment of the content of residual monomers and organic saturated volatiles, for health and environmental reasons sometimes down to minute traces. Former standards for measurement of residual volatiles ba
16、sed on distillation linked with titration cannot cope with such exigences. This part of IS013741 presents an advanced method for the determination, by gas chromatography, of residual monomers and other organic components in polymer dispersions and latices. This standard provides a method that is in
17、line with present-day requirements for analytical methods and is intended for use instead of ISO2008:1987, Rubber latex, styrene-butadiene Determination of volatile unsaturates, and ISO3899:1988, Rubber Nitrile latex Determination of residual acrylonitrile content, where precise measurements of vola
18、tile-matter content are needed, and expands their scope to include other volatile organic components. WARNING This part of ISO13741 does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this part of ISO13741 to establish appr
19、opriate safety and health practices and determine the applicability of regulatory limitations prior touse. 1 Scope 1.1 This part of ISO13741 specifies a method for the determination of residual monomers and other (saturated) organic components in aqueous polymer dispersions and latices as well as in
20、 related products. It makes use of capillary-column gas chromatography with direct injection of the liquid sample. 1.2 Residual monomers and saturated volatiles that have been successfully determined by this method include acrylic and methacrylic esters, acrylonitrile, butadiene, styrene, vinyl acet
21、ate, vinyl chloride as well as by-products such as acetaldehyde and ethylbenzene. Butadiene could be co-eluted with cis-2-butene. 1.3 Since the chromatograms obtained normally contain a series of peaks, it is only possible to determine the content of those volatiles for which response factors have b
22、een determined. For the identification of unknown peaks, auxiliary methods like mass spectroscopy or the use of a second GC column with a different polarity are advisable. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of
23、 this part of ISO13741. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this part of ISO13741 are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Memb
24、ers of IEC and ISO maintain registers of currently valid International Standards. ISO3696:1987, Water for analytical laboratory use Specification and test methods. 3 Principle A test sample is diluted with water containing an internal standard and injected onto the liner of a gas chromatograph with
25、a capillary column, a flame ionization detector and a linear temperature programming capability. 4 Reagents Unless otherwise stated, use only reagents of recognized analytical grade and only grade1 water as defined in ISO3696. 4.1 Carrier gas: nitrogen or helium of99,995% (orhigher) purity. 4.2 Prop
26、ionitrile, 99% purity, for use as internal standard. Propionitrile has been found to be a suitable internal standard, but other at least partly water-soluble organic compounds not found in the sample could be used as the internal standard, e.g.iso-butyl acetate or methyl iso-butyl ketone. The intern
27、al standard shall yield a clear chromatographic separation and shall not interfere with any component originally present in the sample. 4.3 Monomers and other organic compounds of interest, 99% purity, for comparison purposes. 4.4 Dimethylformamide (DMF). 4.5 Tetrahydrofuran (THF). 5 Apparatus Ordin
28、ary laboratory equipment, plus the following: 5.1 Gas chromatograph, having an injection port designed for split operation, with a liner of atleast1cm 3volume, a flame-ionization detector (FID) and a linear temperature programming capability for the column.BSISO 13741-1:1998 2 BSI 04-1999 5.2 Capill
29、ary column, of length30m and internal diameter0,53m, made of fused silica that is covered inside with a14m to54m thick film of a dimethylpolysiloxane. 5.3 Integrator or suitable recorder. The recorder shall have a full-scale deflection of10mV, a time to full-scale deflection of2s or less, and a maxi
30、mum noise level of 0,03%. 5.4 Microsyringe, capacity104l to504l. NOTEIt has been found that504l microsyringes are more reliable and stable than smaller syringes. The needle is not prone to clogging. However, small(104l) microsyringes could, in principle, also be used. 5.5 Analytical balance, accurat
31、e to0,1mg. 5.6 Volumetric flasks, capacity50cm 3and1000cm 3 . 6 Preparation of apparatus 6.1 Partly fill the insert liner with a piece of stainless-steel gauze with80 to325 mesh(1804m to454m) to retain solids during injection. 6.2 Condition the column by attaching one end of the column to the inlet
32、side of the apparatus, leaving the exit end of the column disconnected. This prevents contamination of the detector due to column bleed. Set the carrier gas flow rate to the value given in the instruction manual and purge the column at220 C for1h (or longer). 6.3 After conditioning, connect the exit
33、 end of the column to the detector and establish the operating conditions required to give the desired separation (for typical conditions, see Table 1). Allow sufficient time for the apparatus to reach equilibrium as indicated by a stable baseline. 6.4 Control the detector temperature so that it is
34、constant to within1 C, without thermostat cycling which causes an uneven baseline. Table 1 Typical operating conditions a Detector flame ionization Air flow rate 240cm 3 /min Hydrogen flow rate 30cm 3 /min Make-up gas flow rate 30cm 3 /min Column Length 30m Inside diameter 0,53mm Film thickness 1 4m
35、 to54m (dimethylpolysiloxane) Carrier gas nitrogen or helium Flow rate 4cm 3 /min Purge rate 1cm 3 /min to2 cm 3 /min Temperatures Injection port 150 C to200 C Detector block 250 C Initial column temperature 50 C Hold time 5minutes Programme rate 5 C/min Final column temperature 200 C (or higher as
36、needed) Final hold time b 7minutes (or longer) Injection volume approx.14l Split ratio 10 : 1 to100 : 1 a It may be necessary to modify these conditions if separation problems are encountered or if other conditions are specified in the gas chromatograph manufacturers instructions. For instance a col
37、umn with an inside diameter0,53mm may be more suitable: in this case, reduce the carrier gas flow rate to ca.1cm 3 /min. b After the final hold, heating to300 C or320 C is recommended to purge the column.BS ISO 13741-1:1998 BSI 04-1999 3 7 Calibration 7.1 For reliable results, it is necessary to cal
38、ibrate the instrument for each analysis with respect to sensitivity and retention time. This is done by determining the response factors and retention times for each component expected to be present in the dispersion or the latex by injecting small amounts of the internal standard together with the
39、individual components, or mixtures thereof, dissolved in a solvent (e.g.dimethylformamide or tetrahydrofuran). 7.2 Weigh, to the nearest0,1mg, about100mg of propionitrile and50mg to200mg of the volatile of interest (three to four different amounts are recommended) into a50cm 3volumetric flask. Make
40、up to the mark with dimethylformamide or tetrahydrofuran and mix well. 7.3 Inject a14l aliquot of the solution prepared in7.1 onto the column and record the chromatogram. Use the same instrument conditions as for sample analysis. The elution order for typically occurring volatiles is given below: ac
41、etaldehyde 1,3-butadiene acrylonitrile propionitrile vinyl acetate methyl acrylate n-butanol ethyl acrylate methyl methacrylate 4-vinylcyclohexene ethylbenzene n-butylacrylate styrene 2-ethylhexyl acrylate 4-phenylcyclohexene 7.4 Measure the peak areas of the individual components and calculate the
42、relative response factor R ffor each component as follows: where 7.5 Calculate the mean response factor for eachvolatile. 7.6 Repeat this calibration as needed. 7.7 Typical response factors are: 8 Procedure 8.1 Prepare a dilute solution of the internal standard by weighing, to the nearest0,1mg, abou
43、t250mg of propionitrile into a1000cm 3volumetric flask. Make up to the mark with water (grade1). Shake gently. Calculate the mass fraction w Sof the internal standard in this solution, expressed in milligrams per kilogram. Prepare a fresh solution each day the test method is carried out. Take care t
44、o minimize losses due to evaporation. 8.2 Weigh out, to the nearest0,01g, about10g (orasuitable fraction of10g) of the sample (m d ), and add30g (or the same fraction of30g as for the sample), also weighed to the nearest0,01g, of the internal standard solution prepared in8.1 (m S ). 8.3 Inject appro
45、ximately14l of the sample solution prepared in8.2 onto the insert liner of the gas chromatograph using the instrument conditions given in Table 1 or similar conditions. NOTEIt is advisable to use a504l syringe for the injection to avoid problems with clogging of the needle due to film formation. Imm
46、ediately after injection, clean the syringe with water (grade1) and with a water-miscible solvent (for example tetrahydrofuran). 8.4 Clean or replace the insert liner after every10 to20 injections. 8.5 Measure the peak areas of the internal standard, A S , and of the relevant volatiles, A V . R f is
47、 the response factor for the volatile of interest relative to the internal standard; A S is the peak area of the internal standard (propionitrile); Rf A S m V A V m S - = A V is the peak area of the volatile of interest; is the mass of the internal standard in the calibration mixture; is the mass of
48、 the volatile of interest in the calibration mixture. butadiene 0,6 4-vinylcyclohexene 0,6 ethylbenzene 0,6 n-butyl acrylate 0,95 styrene 0,6 m S m VBSISO 13741-1:1998 4 BSI 04-1999 9 Calculation Calculate the mass fraction w V , in milligrams per kilogram, of each volatile present in the polymer di
49、spersion/latex as follows: where EXAMPLE 260mg of propionitrile was made up to1000g withwater (w S =260mg/kg).10g of polymer dispersion/latex (m d =10g) was mixed with30g of internal standard solution (m S =30g). The peak area of the propionitrile was18000 units and that of the volatile24000 units. The response factor was determined to be0,8. Then A typical chromatogram is shown in Figure 1. Report results which are lower than10mg/kg (thedetection limit) as10mg/kg. 10 Precision Duplicates should
