1、Designation: D4754 11Standard Test Method forTwo-Sided Liquid Extraction of Plastic Materials Using FDAMigration Cell1This standard is issued under the fixed designation D4754; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 and permits quantitati
3、on 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 test method has been app
4、lied 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 been shown to yield rep
5、roducibleresults 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 plastics intendedfor
6、 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 D1898, the AOAC Meth-ods of Analysis on Flexible Barrier Materials Exposed for Extraction, andthe
7、Guidance for Industry: Preparation of Premarket Submissions for FoodContact Substances: Chemistry Recommendations, December 2007.1.7 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
8、.9 This standard does not purport 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 hazard
9、sstatements are given in Section 8.NOTE 2There is no known ISO equivalent to this test method.2. Referenced Documents2.1 ASTM Standards:4D883 Terminology Relating to PlasticsD1898 Practice for Sampling of Plastics5E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a T
10、est MethodIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modernized Metric System2.2 Association of Offcial Analytical Chemists (AOAC)Methods of Analysis:Flexible Barrier Materials Exposed for Extraction62.3 Federal Document:Guidance for Industry: Preparation of Prema
11、rket Submis-sions for Food Contact Substances: Chemistry Recom-mendations, December 200773. Terminology3.1 GeneralThe units, symbols, and abbreviations used inthis test method are in accordance with Terminology D883 andPractice IEEE/ASTM SI 10.4. Summary of Test Method4.1 Specimens of plastic materi
12、als, formed in the shape ofdisks, are threaded onto a stainless steel wire with alternatingglass 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 at1This test method is
13、under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved Dec. 1, 2011. Published December 2011. Originallyapproved in 1987. Last previous edition approved in 2003 as D4754 98(2003).DOI: 10.1520/D475
14、4-11.2“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:D20-1141.4For referenced ASTM standards, visit the ASTM website, www.astm.o
15、rg, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.5Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.6Available through the Associati
16、on of Official Analytical Chemists, 481 NorthFrederick Avenue, Suite 500, Gaithersburg, Maryland 20877-2417 USA.7Available from Division of Food Contact Notifications, Office of FoodAdditiveSafety, Center for Food Safety and Applied Nutrition, Food and Drug Administra-tion, College Park, MD 20740, U
17、SA.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.various times and the migrant(s) in the liquid determined bysuitable analytical methods.NOTE 3 Significant migration
18、 loss due to volatility may occur ifmigration is carried out at temperatures exceeding 50C for periodsgreater 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 procedur
19、e described in thistest method is recommended as suitable for obtaining such dataon many migrant(s)/plastic(s) combinations.6. Apparatus6.1 FDA Migration Cell8(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 (
20、5-mm diameter), containing hole slightlylarger than diameter of stainless steel wire.9(Available at 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-su
21、rface area ideally should bebetween 155 and 0.31 mL/cm2.) Note that validation tests have only beenconducted 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
22、provisions and capable of maintaining thedesired extraction temperature within 61C.6.3 Thermostatted Shaker Water Bath8,10Some 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
23、 removing liquid aliquots from thecells and transferring them to the analytical instrumentation.6.5 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 b
24、e free of interferences inthe detection region of the migrant(s).8. Hazards8.1 The usual safety precautions for handling flammablesolvents are recommended when such solvents are used forextraction.9. Sampling9.1 Sample the plastic in accordance with Practice D1898.9.2 Select representative samples o
25、f the plastic to be testedfrom available stock on hand. Film, pellets, powders, sheet,and, in some cases, actual end-use articles are suitable. Protectthe samples from exposure to liquids or contamination bymigration from contact with other materials.NOTE 6See RR:D20-1141 for details regarding sampl
26、e test speci-mens.10. Test Specimen10.1 Test specimens in the form of round disks (11 by 1mm) are 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 form
27、ed by using a heated press and anappropriate shim or mold containing holes the size of the disk.Holes 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,
28、the cut edges of thedisks may have a different structure than the surfaces, and henceforth themigration 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
29、 can be runcomparing disks formed by using a heated press with disks cut from asheet formed under 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.
30、 Place resulting stacks of disks into23 mL glass vials. Add 22 mL of extraction liquid and screwMininertt caps tightly onto the vials.8The 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 168
31、23. If you are aware of alternative suppliers, please provide this informationto ASTM International Headquarters. Your comments will receive careful consid-eration at a meeting of the responsible technical committee1, which you may attend.9Glass beads sold at hobby shops have been found satisfactory
32、 for this purpose.10The sole source of supply of the thermostatted shaker water bath known to thecommittee at this time is Precision Scientific, 3737 W. Cortland St., Chicago, IL60647.FIG. 1 FDA Migration CellD4754 11211.2 Use the above prepared vials to determine the totalamount of migrant(s).11.3
33、To calculate migration rates, the samples should bewashed to remove any surface bloom of 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 th
34、e test speci-mens were prepared, removal of any migrant surface bloom might not bewarranted. 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
35、 migration,place extraction solvent(s) and known quantities of the mi-grant(s) to be studied 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 cont
36、aining the support stand with glass beadspacers. Place these blank vials in the same thermostatted 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 e
37、ach sampling, check to see if cell caps are tight.NOTE 11Volume withdraw is dictated by 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 to
38、quantitate the migrant(s).13. Calculation13.1 The test results can be calculated in a number 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 pe
39、r million (ppm) or partsper billion (ppb).13.3 A second way to express the test results is in milli-grams of migrant(s) per square metre of sample exposed, E,asfollows:E5W2B!/2pR21CT!Nwhere:W = total weight of migrant(s) in the liquid, mg,B = weight of migrant(s) in the blank, mg,R = radius of the d
40、isk, m,C = circumference of disk, m,T = thickness of disk, m, andN = number of disks per 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
41、scope of this test method. A briefdescription is contained in Appendix X1.14. Report14.1 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
42、conducted in 1984 inaccordance with Practice E691. Twelve laboratories reportedresults (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. O
43、ne aliquot was takenfrom each cell at six times over 2 weeks. A test result wasobtained 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 approximatepreci
44、sion of this test method. The data in Table 1 should not be rigorouslyapplied to acceptance 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
45、outlined in Practice E691 to generate data specific to theirlaboratory and materials, 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 testr
46、esults that were averages from testing 5 sample cells:15.2.1 Repeatability, r (Comparing 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 ma
47、terial.15.2.2 Reproducibility, R (Comparing two test results for thesame material, obtained 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 acco
48、rdance with 15.2.1 and15.2.2 would have an approximate 95 % (0.95) probability ofbeing 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 ti
49、mes over the 2-week migration period.From the detector response for these four standards, 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 2.32ASr= within-laboratory standard deviation of the average,BSR= between-laboratories standard deviation of the average,Cr = 2.83 Sr, andDR=2.83SR.D4754 113detector response per 1
