1、Designation: D 4754 98 (Reapproved 2003)Standard Test Method forTwo-Sided Liquid Extraction of Plastic Materials Using FDAMigration Cell1This standard is issued under the fixed designation D 4754; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the use of the FDA migrationcell in the extraction of components a
3、nd permits quantitation ofindividual migrants from plastic materials by suitable extract-ing liquids, including liquid foods and food-stimulating sol-vents.1.2 This test method provides a two-sided, liquid extractiontest for plastic materials that can be formed into film, sheet, ordisks.1.3 This tes
4、t method has been applied to a variety ofmigrant/polymer systems in contact with numerous foods andfood simulants.2Though most of the migrants examined wereradiolabeled, the use of the FDA cell has been validated formigration studies of unlabeled sytrene from polystyrene.31.4 This test method has be
5、en shown to yield reproducibleresults under the conditions for migration tests requested by theFDA. However, if the data is to be submitted to the FDA, it issuggested that their guidelines be consulted.1.5 Because it employs two-sided extraction, this testmethod may not be suitable for multi-layered
6、 plastics intendedfor single-sided food contact use.1.6 The size of the FDA migration cell as described maypreclude its use in determining total nonvolatile extractives insome cases.NOTE 1For more information, see Practice D 1898, the AOACMethods of Analysis on Flexible Barrier Materials Exposed for
7、 Extrac-tion, and the 1995 Recommendations for Chemistry Data for IndirectFood Additive Petitions.1.7 Analytical procedures must be available to quantitatethe migrant(s) generated by this test method.1.8 The values stated in SI units are to be regarded as thestandard.1.9 This standard does not purpo
8、rt to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardsstatements are given in Sectio
9、n 8.NOTE 2There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:D 883 Terminology Relating to Plastics4D 1898 Practice for Sampling of Plastics5E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method6IEEE/ASTM SI 10 Standar
10、d for Use of the InternationalSystem of Units (SI): The Modernized Metric System62.2 Association of Offcial Analytical Chemists (AOAC)Methods of Analysis:Flexible Barrier Materials Exposed for Extraction72.3 Federal Document:1995 Recommendations for Chemistry Data for IndirectFood Additive Petitions
11、83. Terminology3.1 GeneralThe units, symbols, and abbreviations used inthis test method are in accordance with Terminology D 883 andPractice E 380.4. Summary of Test Method4.1 Specimens of plastic materials, formed in the shape ofdisks, are threaded onto a stainless steel wire with alternatingglass
12、bead spacers and placed in a glass vial. Solvent is addedto the vial and the vial is capped and maintained at the desiredextraction temperature. Aliquots of the liquid are removed atvarious times and the migrant(s) in the liquid determined bysuitable analytical methods.NOTE 3 Significant migration l
13、oss due to volatility may occur if1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved March 10, 2003. Published May 2003. Originallyapproved in 1987. Last previous edition
14、approved in 1998 as D 4754 98.2“A Study of Indirect Food Additive Migration,” Arthur D. Little, Inc., FDAContract No. 223-77-2360.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D201141.4Annual Book of ASTM Standards, Vol 08.01
15、.5Discontinued. See 1997 Annual Book of ASTM Standards, Vol 08.01.6Annual Book of ASTM Standards, Vol 14.02.7Available through the Association of Official Analytical Chemists, Washington,DC.8Available from Chemistry Review Branch, Office of Premarket Approval,Center for Food Safety and Applied Nutri
16、tion, Food and Drug Administration,Washington, DC 20204.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.migration is carried out at temperatures exceeding 50C for peri
17、odsgreater than 2 weeks.5. Significance and Use5.1 Knowledge of migrants from plastic materials mayserve many useful purposes, such as testing for compliancewith food additive regulations. The procedure described in thistest method is recommended as suitable for obtaining such dataon many migrant(s)
18、/plastic(s) combinations.6. Apparatus6.1 FDA Migration Cell9(Fig. 1), consisting of:6.1.1 Glass Vials, 23-mL,6.1.2 Mininertt Slide Valve Caps,6.1.3 Stainless Steel Wire (20-gage), and6.1.4 Glass Bead (5-mm diameter), containing hole slightlylarger than diameter of stainless steel wire.10(Available a
19、t localhobby shops.)NOTE 4The apparatus, disk size, and number of disks are describedfor the 23-mL vial. Alternative vial sizes and corresponding test specimensizes may be substituted. (The volume-to-surface area ideally should bebetween 155 and 0.31 mL/cm2.) Note that validation tests have only bee
20、nconducted using the 23-mL vials.NOTE 5Recommend one-time use of mininert valve (that is, discard-ing it at completion of study).6.2 Hot-Air Oven or Static Thermostatted Water Bath, withsuitable safety provisions and capable of maintaining thedesired extraction temperature within 61C.6.3 Thermostatt
21、ed Shaker Water Bath9,11Some migrant/plastic/liquid combinations may involve significant partition-ing and would benefit by having the cells shaken throughoutthe migration study.6.4 Liquid Syringes, for removing liquid aliquots from thecells and transferring them to the analytical instrumentation.6.
22、5 Analytical Instrumentation, as required by the methodchosen to determine the migrant(s).7. Reagents and Materials7.1 Purity of ReagentsAll solvents shall be HPLC orchromatographic grade and shown to be free of interferences inthe detection region of the migrant(s).8. Hazards8.1 The usual safety pr
23、ecautions for handling flammablesolvents are recommended when such solvents are used forextraction.9. Sampling9.1 Sample the plastic in accordance with Practice D 1898.9.2 Select representative samples of the plastic to be testedfrom available stock on hand. Film, pellets, powders, sheet,and, in som
24、e cases, actual end-use articles are suitable. Protectthe samples from exposure to liquids or contamination bymigration from contact with other materials.NOTE 6See RR: D201141 for details regarding sample test speci-mens.10. Test Specimen10.1 Test specimens in the form of round disks (11 by 1mm) are
25、 prepared from the plastic to be tested. Disks can bestamped out of sheets of actual end-use articles of non-brittleplastic by means of the appropriate sized cork borer. Alterna-tively, disks can be formed by using a heated press and anappropriate shim or mold containing holes the size of the disk.H
26、oles can be put in the center of the disk by means of a drillor a heated wire.NOTE 7Whenever possible, plastic from actual end-use articlesshould be tested.NOTE 8When actual end-use articles are tested, the cut edges of thedisks may have a different structure than the surfaces, and henceforth themig
27、ration rates may be altered. Because the area of the surfaces is muchgreater than that of the cut edges, the effect of the edges would be limited.If a significant edge effect is suspected, however, tests can be runcomparing disks formed by using a heated press with disks cut from asheet formed under
28、 similar conditions.11. Preparation of Apparatus11.1 Alternately thread glass beads and 14 plastic disks ontothe stainless steel wire (see Fig. 1). Prepare at least 4 sets foreach liquid extractant used. Place resulting stacks of disks into23 mL glass vials. Add 22 mL of extraction liquid and screwM
29、ininertt caps tightly onto the vials.9The sole source of supply of the FDA Migration Cell components known to thecommittee at this time is Supelco, Inc., P.O. Box 628, 146 S. Water St., Bellefonte,PA 16823. If you are aware of alternative suppliers, please provide this informationto ASTM Internation
30、al Headquarters. Your comments will receive careful consid-eration at a meeting of the responsible technical committee1, which you may attend.10Glass beads sold at hobby shops have been found satisfactory for this purpose.11The sole source of supply of the thermostatted shaker water bath known to th
31、ecommittee at this time is Precision Scientific, 3737 W. Cortland St., Chicago, IL60647.FIG. 1 FDA Migration CellD 4754 98 (2003)211.2 Use the above prepared vials to determine the totalamount of migrant(s).11.3 To calculate migration rates, the samples should bewashed to remove any surface bloom of
32、 the migrant(s).Maintain the above prepared vials at the extraction temperaturefor 2 h. Discard the liquid in the vials and replenish with freshextracting liquid.NOTE 9Depending upon the conditions under which the test speci-mens were prepared, removal of any migrant surface bloom might not bewarran
33、ted. Under these conditions, simply omit the wash step forremoving migrant surface bloom.12. Procedure12.1 Place properly prepared vials in thermostatted oven orbath.12.2 To prepare standards for quantitating the migration,place extraction solvent(s) and known quantities of the mi-grant(s) to be stu
34、died in a vial containing the support stand withglass bead spacers. Place these standard vials in the samethermostatted oven or bath.12.3 To prepare the blank, place only the extraction sol-vent(s) in a vial containing the support stand with glass beadspacers. Place these blank vials in the same the
35、rmostatted ovenor bath.12.4 At pre-selected times, typically 5 to 8 samplings overa 2-week period, withdraw L aliquots from each sample,standard, and blank vial and analyze using selected methodol-ogy.NOTE 10At each sampling, check to see if cell caps are tight.NOTE 11Volume withdraw is dictated by
36、analytical procedure beingutilized. If aliquots of more than 1 % by volume are removed duringsamplings, separate vials should be used for each test period.12.5 Use response of standards on each day of analysis toquantitate the migrant(s).13. Calculation13.1 The test results can be calculated in a nu
37、mber of waysdepending upon the application of the data.13.2 One simple way to express the test results is tocalculate the concentration of the migrant(s) in the liquid at agiven time in some unit such as parts per million (ppm) or partsper billion (ppb).13.3 A second way to express the test results
38、is in milli-grams of migrant(s) per square metre of sample exposed, E,asfollows:E5W2B!/2pR21CT!N#where:W = total weight of migrant(s) in the liquid, mg,B = weight of migrant(s) in the blank, mg,R = radius of the disk, m,C = circumference of disk, m,T = thickness of disk, m, andN = number of disks pe
39、r cell.13.4 A third and more rigorous way to express the testresults is to calculate diffusion and partition coefficients for theplastic/migrant(s)/liquid system used. These calculations, how-ever, are beyond the scope of this test method. A briefdescription is contained in Appendix X1.14. Report14.
40、1 Report the test results, either as concentration ofmigrant(s) per unit volume of liquid, or concentration ofmigrant(s) per square metre of disk area.15. Precision and Bias315.1 Table 1 is based on a round-robin conducted in 1984 inaccordance with Practice E 691. Twelve laboratories reportedresults
41、 (ppm) for styrene migration from polystyrene disks into50/50 ethanol/water at 49C. The disks were prepared at onesource. Five replicate sample cells were then setup by eachlaboratory which conducted the studies. One aliquot was takenfrom each cell at six times over 2 weeks. A test result wasobtaine
42、d from the analysis of each aliquot. Each laboratoryreported 30 test results.NOTE 12 The following explanations of Irand IR(see 15.2) are onlyintended to present a meaningful way of considering the approximateprecision of this test method. The data in Table 1 should not be rigorouslyapplied to accep
43、tance or rejection of material, as those data are specific tothe round-robin and may not be representative of other lots, conditions,materials, or laboratories. Users of this test method should apply theprinciples outlined in Practice E 691 to generate data specific to theirlaboratory and materials,
44、 or between specific laboratories. The principlesof 15.2 through 15.2.3 would then be valid for such data.15.2 Concept of r and RSince Srand SRhave beencalculated from data produced by 12 laboratories, and for testresults that were averages from testing 5 sample cells:15.2.1 Repeatability, r (Compar
45、ing two test results for thesame material, obtained by the same operator using the sameequipment on the same day)The two test results should bejudged not equivalent if they differ by more than the r value forthat material.15.2.2 Reproducibility, R (Comparing two test results for thesame material, ob
46、tained by different operators using differentequipment on different days)The two test results should bejudged not equivalent if they differ by more than the R valuefor that material.15.2.3 Any judgement made in accordance with 15.2.1 and15.2.2 would have an approximate 95 % (0.95) probability ofbein
47、g correct.15.3 The integrity of this cell was evaluated by carryingstandards along with the actual migration cells. Each of the 12participating laboratories analyzed standards at four differentconcentrations, six times over the 2-week migration period.From the detector response for these four standa
48、rds, an averageTABLE 1 Precision for Migration of Residual Styrene fromPolystyreneTime, hValues in ppmAvg SrASRBrCRD4 0.222 0.022 0.11 0.062 0.3124 0.979 0.080 0.12 0.226 0.3472 2.282 0.153 0.27 0.433 0.76168 3.875 0.198 0.46 0.560 1.30240 4.790 0.197 0.62 0.558 1.75336 5.711 0.276 0.82 0.781 2.32AS
49、r= within-laboratory standard deviation of the average,BSR= between-laboratories standard deviation of the average,Cr = 2.83 Sr, andDR = 2.83 SR.D 4754 98 (2003)3detector response per 1 ppm of styrene was calculated (that is,slope of linear least squares fit, forced through origin). Thecoefficient of variation for the six average detector responsesfor the 12 laboratories ranged from 0.6 to 9.5 % and averaged4.9 %.15.4 BiasThere are no recognized standards on which tobase an estimate of bias for this test method.16. Keywords16.1 diffusion; food packaging;
