1、Designation: D8130 17Standard Test Method forDetermination of Metals in Purified Terephthalic Acid (PTA)by Inductively Coupled Plasma Atomic EmissionSpectrometric Method1This standard is issued under the fixed designation D8130; the number immediately following the designation indicates the year ofo
2、riginal adoption or, in the case of revision, the year 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. Scope1.1 This test method covers the determination of metalelements i
3、n purified terephthalic acid (PTA) by inductivelycoupled plasma atomic emission spectrometry (ICP-AES).Thismethod is applicable to PTA samples containing sodium,chromium, cobalt, aluminum, titanium, potassium,magnesium, manganese, iron, nickel, molybdenum and cal-cium over 0.055 mg/kg, respectively.
4、1.2 In determining the conformance of the test results usingthis method to applicable specification, results shall be roundedoff in accordance with the rounding-off method of PracticeE29.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in th
5、isstandard.1.4 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, health and environmental practices and deter-mine the applicability of regulatory limitations pr
6、ior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization Technical
7、Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD4790 Terminology of Aromatic Hydrocarbons and RelatedChemicalsD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsD7111 Test
8、Method for Determination of Trace Elements inMiddle Distillate Fuels by Inductively Coupled PlasmaAtomic Emission Spectrometry (ICP-AES)E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE177 Practice for Use of the Terms Precision and Bias inASTM Test
9、MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Document:3EN ISO 8213 Chemical products for industrial useSampling techniquesSolid chemical products in theform of particles varying from powders to coarse lumps2.3 Other Document:4OSHA Reg
10、ulations, 29 CFR paragraphs 1910.1000 and1910.12003. Summary of Test Method3.1 A PTA sample is dissolved in ammonium hydroxidesolution. Calibration standards are prepared by mixing metallicstandard materials in ammonium hydroxide solution. An inter-nal standard material is added to the calibration s
11、tandards andthe sample solution to compensate for variations of testspecimen introduction efficiency. The calibration standards andthe sample solution are aspirated into the ICP-AES instrument.The concentrations of the elements in the sample solution arecalculated by comparing emission intensity rat
12、ios of the samplesolution and calibration standards to the internal standard.4. Significance and Use4.1 The presence of metals in PTA used for the productionof polyester is undesirable because they may speed up or slowdown the reaction and be impurities in the final product.1This test method is unde
13、r the jurisdiction of ASTM Committee D16 onAromatic, Industrial, Specialty and Related Chemicals and is the direct responsi-bility of Subcommittee D16.02 on Oxygenated Aromatics.Current edition approved Aug. 1, 2017. Published September 2017. DOI:10.1520/D8130-17.2For referenced ASTM standards, visi
14、t the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York,
15、 NY 10036, http:/www.ansi.org.4Available from U.S. Government Printing Office, Superintendent ofDocuments, 732 N. Capitol St., NW, Washington, DC 20401-0001, http:/www.access.gpo.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis
16、 international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TB
17、T) Committee.14.2 Determination of the metals in PTA is often required.This test method is suitable for setting specifications and foruse as an internal quality control where these products areproduced or used.4.3 This test method covers the determination of sodium,chromium, cobalt, aluminum, titani
18、um, potassium,magnesium, manganese, iron, nickel, molybdenum and cal-cium.5. Apparatus5.1 Inductively-Coupled Plasma Atomic EmissionSpectrometerAny commercial sequential or simultaneousICP-AES instrument capable of measuring emission intensitiesof the elements of interest (listed in Table 1).5.2 Ana
19、lytical Balance, readable to 60.0001 g.6. Reagents and Materials6.1 Purity of ReagentsUnless otherwise indicated, it isintended that all reagents shall conform to the reagent gradespecification for analytical reagents of the American ChemicalSociety,5where such specifications are available. Other gr
20、adesmay be used, provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe performance or accuracy of the determination. Reagentchemicals shall be used for all tests.NOTE 1Calibration and detection limits of this test method can bebiased b
21、y the purity of the reagents.6.2 Argon Gas99.99% minimum purity. (WarningArgon is under high pressure.)6.3 Nitrogen Gas99.99% minimum purity. (WarningNitrogen is under high pressure.)6.4 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Type I reagent watercon
22、forming or exceeding Specification D1193. Freshly drawnwater should be used for preparation of all stock and workingstandards, and sample solutions.6.5 Ammonium Hydroxide25 to 28 %(wt).NOTE 2The metal impurities in ammonia hydroxide should be nomore than 10 g/kg, and the non-metallic impurities shou
23、ld be no morethan 100 mg/kg. The reagent may be purchased.6.6 Ammonium Hydroxide SolutionPipette 13 mL of am-monia hydroxide (6.5) to a 100 mL volumetric flask, fill thevolumetric flask to the mark with water.6.7 Internal Standard Stock Solution1000 mg/L. Thesingle element chosen for the internal st
24、andard should not be acomponent of the sample or calibration standard. Cadmiumand yttrium were found to perform well as an internal standardfor this test method and are recommended. The standard maybe purchased.6.8 Internal Standard Solution100 mg/L. Pipette 10 mLofInternal Standard stock solution (
25、6.7) to a 100 mL volumetricflask, fill the volumetric flask to the mark with water.6.9 Single Element Standard Stock Solution1000 mg/L.The test elements are listed in Table 1. The standards may bepurchased.6.10 Single Element Standard Solution100 mg/L. Pipette10 mL of the single element standard sto
26、ck solution (6.9)toa100 mL volumetric flask, fill the volumetric flask to the markwith water.6.11 Multi-element Mixed Standard Solution1.0 mg/L.Pipette 1 mL of each single element standard solution (6.10)toa 100 mL volumetric flask, fill the volumetric flask to thevolume mark with water. Seal the vo
27、lumetric flask and mixwell. Prepare fresh multi-element mixed standard solutiondaily when samples are to be analyzed.6.12 Working StandardsThe working standards are pre-pared as follows: pipette 0, 0.5, 1.0, 2.0, 3.0 and 5.0 mL of themulti-element mixed standard solution (6.11) into six separate100
28、mL volumetric flasks. And then pipette 0.2 mL of theinternal standard (6.8) into each volumetric flask. Dilute to themark with the ammonium hydroxide solution (6.6). Seal thevolumetric flask and mix well. The working standards will be0.0, 5.0, 10.0, 20.0, 30.0, 50.0 g/L of each element of interest,a
29、nd 200.0 g/L of internal standard. Working standards are tobe prepared daily when samples are to be analyzed.7. Hazards7.1 Consult current federal regulations, suppliers SafetyData Sheets, and local regulations for all materials used in thistest method.8. Sampling and Test Specimens8.1 Use only repr
30、esentative samples obtained as describedin EN ISO 8213, unless otherwise specified.9. Preparation of Apparatus9.1 Prepare the ICP spectrometer according to the manufac-turers instructions and parameter settings for the elements of5Reagent Chemicals, American Chemical Society Specifications, American
31、Chemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC),
32、Rockville,MD.TABLE 1 Element and Recommended WavelengthsAElement Wavelength (nm)Cobalt 228.616Manganese 257.610Iron 238.204Chromium 267.716Nickel 221.648Sodium 589.592Titanium 334.940Molybdenum 202.033Magnesium 285.231Potassium 766.490Calcium 317.933Aluminum 396.153CadmiumB228.802YttriumB371.029AThe
33、se wavelengths are only suggested and do not represent all possiblechoices. Other appropriate interference free wavelengths may also be used.Consult instrument manufactures instructions or other ICP-AES references.BCadmium and Yttrium are used as internal standards.D8130 172interest. Table 1 provide
34、s recommended element wavelengthsfor PTA, other wavelengths may be used due to possibleinstrument variations or spectral interferences from sample.The optical path of ICP-AES can be purged with argon oranother high purity gas (for example, nitrogen) recommendedby the manufacturer. Before igniting th
35、e plasma, inspect thequartz torch to make sure that it is clean. If carbon build-up isobserved, replace the torch and make the manufacturersrecommended adjustments for this problem. Warm up theinstrument while purging the optics for the time periodrecommended by the ICP manufacturer.10. Procedure10.
36、1 Calibration:10.1.1 Aspirate ammonium hydroxide solution (6.6) andzero the instrument. Analyze the working standards (6.12). Acalibration curve is constructed by plotting the concentrationsof each element of interest on the X-axis and the emissionintensity ratios of each element to the internal ele
37、ment on theY-axis. Most ICP spectrometers have software that automati-cally performs the calculations to establish the calibrationcurve when using an internal standard. The calibration curveneeds to be performed when a new batch of samples is to beanalyzed.10.2 Analysis of Samples:10.2.1 Weigh, to t
38、he nearest 0.0001 g, 7 to 7.5 g of PTAsample, and dissolved in ammonia hydroxide solution (6.6).Quantitatively transfer dissolved sample into a 100 mL volu-metric flask, pipette 0.2 mL of the internal standard (6.8), anddilute with ammonia hydroxide solution (6.6) to the mark. Sealthe volumetric fla
39、sk and mix well.10.2.2 Aspirate ammonium hydroxide solution (6.6) andzero the instrument. Analyze sample solution under the sameconditions that the working standards were run. The ICPinstrument software generates concentration values for eachelement.11. Calculation11.1 Calculate the concentrations o
40、f element i in PTA asfollows:Xi5ci3 vw 3 1000(1)where:Xi= concentration of element i in PTA sample, mg/kg,ci= concentration of element i in the sample solution, g/L,v = volume of volumetric flask, mL, andw = weight of PTA sample, g.12. Report12.1 Report the average value of metal content in mg/kg, t
41、othe nearest 0.001 mg/kg. In condition of concentration of theelement of interest in PTA sample less than 0.055 mg/kg, theresults should be reported 0.055 mg/kg, respectively.12.2 Report the following information in the report.12.2.1 The complete identification of the sample tested.12.2.2 Any deviat
42、ion from the procedure specified.12.2.3 Results of the test.12.2.4 Any abnormal situations observed during the test.13. Precision and Bias13.1 The precision of this test method is based on anintra-laboratory study of Test Method D8130, Determination ofMetals in Purified Terephthalic Acid (PTA) by In
43、ductivelyCoupled Plasma Atomic Emission Spectrometric Method,conducted in 2017. One laboratory tested one PTA sample formetals. Every test result represents an individual determina-tion. The laboratory reported 20 replicate results for eachanalysis/material combination in order to estimate the repea
44、t-ability limits of the standard. Practice E691 was followed forthe design and analysis of the repeatability data; the details aregiven in Research Report No. RR:D16-1062.613.1.1 Repeatability Limit (r)Two test results obtainedwithin one laboratory shall be judged not equivalent if theydiffer by mor
45、e than the “r” value for that material; “r”istheinterval representing the critical difference between two testresults for the same material, obtained by the same operatorusing the same equipment on the same day in the samelaboratory.13.1.1.1 Repeatability limits are listed in Table 2.13.1.2 BiasAt t
46、he time of the study, the test specimenschosen for analysis were not accepted reference materialssuitable for determining the bias for this test method, thereforeno statement on bias is being made.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Re
47、search Report RR:D16-1062. ContactASTM CustomerService at serviceastm.org.TABLE 2 Repeatability Limits (mg/kg)Cobaltmg/kgManganesemg/kgIronmg/kgChromiummg/kgNickelmg/kgSodiummg/kgAVERAGE 0.0346 0.5766 0.3306 0.1767 1.5794 0.2020SD 0.0097 0.0125 0.0023 0.0015 0.0112 0.0069r 0.0270 0.0351 0.0064 0.004
48、2 0.0313 0.0193Titaniummg/kgMolybdenummg/kgMangesiummg/kgPotassiummg/kgCalciummg/kgAluminummg/kgAVERAGE 0.6037 0.4965 0.0406 0.1008 0.0509 0.0309SD 0.0034 0.0119 0.0015 0.0039 0.0039 0.0026r 0.0095 0.0334 0.0043 0.0110 0.0110 0.0073D8130 17314. Quality Guidelines14.1 Laboratories shall have a qualit
49、y control system inplace.14.1.1 Confirm the performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of standard statistical quality control practices.14.1.2 A quality control sample is a stable material isolatedfrom the production process and representative of the samplebeing analyzed.14.1.3 When QA/QC protocols are already established inthe testing facility, these protocols are acceptable when theyconfirm the validity of test results.14.1.4 When there is no QA/QC protocols establi
