1、Designation: D 4563 02 (Reapproved 2008)Standard Test Method forDetermination by Atomic Absorption Spectroscopy ofTitanium Dioxide Content of Pigments Recovered FromWhole Paint1This standard is issued under the fixed designation D 4563; the number immediately following the designation indicates the
2、year oforiginal adoption or, in the case 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. Scope1.1 This test method covers the atomic absorption (AA)a
3、nalysis of titanium dioxide content in pigments recoveredfrom whole paint. It is applicable to quality control situationswhere the same type of product is repeatedly analyzed.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1
4、.3 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use. Specific hazard statements
5、 are given inSection 7.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 1394 Test Methods for Chemical Analysis of WhiteTitanium PigmentsE 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 288
6、Specification for Laboratory Glass Volumetric Flasks3. Summary of Test Method3.1 The specimen is prepared for analysis by ashing at450C followed by digestion with sulfuric acid and ammoniumsulfate as in Test Methods D 1394. The titanium content isdetermined by atomic absorption spectroscopy using a
7、speci-men similar to that previously analyzed by the AluminumReduction Method in Test Methods D 1394.3.2 By utilizing the pigment analyzed in Test MethodsD 1394 as an atomic absorption standard, several hundred TiO2determinations can be made. The AA technique is much fasterthan the technique in Test
8、 Methods D 1394 for multipledeterminations and uses only acids. This keeps reagents andtime to a minimum.4. Significance and Use4.1 This test method may be used in quality control labo-ratories when the repeated analysis of titanium dioxide insimilar paints may be required. Reagents and time are kep
9、t toa minimum when this test method is used in place of wetchemical analysis such as in Test Methods D 1394. However,reproducibility and repeatability are not as good as in TestMethods D 1394.5. Apparatus5.1 Atomic Absorption Spectrophotometer, consisting of5.1.1 Atomizer and nitrous oxide burner,5.
10、1.2 Gas-pressure regulator and metering devices for ni-trous oxide and acetylene,5.1.3 Titanium hollow cathode lamp with regulatedconstant-current supply,5.1.4 Monochromator and associated optics,5.1.5 Photosensitive detector connected to an electronicamplifier,5.1.6 Readout device.5.2 Muffle Furnac
11、e, capable of maintaining 450 6 25C.5.3 Circulating Oven, maintained at 105 6 2C.5.4 Porcelain Dishes, 90-mm diameter.5.5 Plastic Disposable Syringe, 10-mL capacity.5.6 Agate Mortar and Pestle, 95-mm outside diameter.5.7 Wide-Mouth Erlenmeyer Flask, 500-mL capacity.5.8 Hot Plate, with variable surfa
12、ce temperature controlfrom 10C above ambient to 370C accurate to within 65C.5.9 Burner.5.10 Volumetric Flask, 1000 mL, plastic (see SpecificationE 288).1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct respon
13、sibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved Feb. 1, 2008. Published February 2008. Originallyapproved in 1986. Last previous edition approved in 2002 as D 4563 - 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or
14、contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.11 Paint Shaker.
15、5.12 Weighing Bottles, wide-mouth, with an external-fittingcap, and no larger than necessary for required amount ofsample.5.13 Desiccator.6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to t
16、he specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficient high purity to permit its use without reducing theaccuracy of the determinat
17、ion.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Type II of Specification D 1193.6.3 Ammonium Hydroxide (sp gr 0.90)Concentrated am-monium hydroxide (NH4OH).6.4 Ammonium Sulfate (NH4)2SO4).6.5 Hydrochloric Acid (sp gr 1.19)C
18、oncentrated hydro-chloric acid (HCl).6.6 Hydrofluoric Acid (HF)Approximately 49 %.6.7 Standard Pigment Solution.6.7.1 Following the procedure in Section 9 recover thepigment from a paint that is similar to the unknown specimen.Analyze the extracted pigment for TiO2content in accordancewith theAlumin
19、um Reduction Method in Test Methods D 1394and record the percent TiO2found in the pigment.6.7.2 Following the procedure in 12.1-12.5 take a specimenof the pigment extracted in 6.7.1 into solution. Store thissolution for no more than 3 months in a plastic bottle markedwith the percent TiO2as determin
20、ed in 6.7.1.6.8 Sulfuric Acid (sp gr 1.84), concentrated sulfuric acid(H2SO4).6.9 Toluene.7. Hazards7.1 Concentrated Hydrofluoric AcidMake certain to ob-serve manufacturers recommended precautions for handling.7.2 WarningNitrous oxide and acetylene can cause ex-plosions, if not used properly. See th
21、e suppliers manual ofinstructions for the atomic absorption instrument for properoperation with these gases.8. Calibration and Standardization8.1 Operational instructions for atomic absorption spectro-photometers vary with different models. Consult the manufac-turers literature for establishing opti
22、mum conditions for thespecific instrument used.8.2 Turn the instrument on and set the wavelength to the365.3-nm titanium line. Apply the recommended current to thetitanium hollow cathode lamp. Allow the instrument to warmup for about 15 min and set the proper slit width.Adjust the gaspressures and i
23、gnite the burner in accordance with instructionsfor using nitrous oxide and acetylene.8.3 Aspirate the water to rinse the atomizer chamber from10 to 15 min until the burner head achieves temperatureequilibrium. Set the instrument reading to zero while doingthis. While aspirating the working standard
24、 from 6.7.2 set theinstrument to the percent TiO2(determined in 6.7.1). Reaspiratethe water and reset the instrument to ZERO. Repeat thisprocedure until the readings become stable.8.3.1 Expanding the scale of a spectrophotometer increasesthe noise level of the readout system. Therefore, if expanding
25、the scale to make the readout indicate 60 % TiO2has thiseffect, do not use any expansion. For instance, it is notnecessary to make the instrument read 60 for 60 % TiO2standard. It may read 30. If 60 % equals 30, a pigment givinga reading of 25 would have a TiO2content of 50 %.PIGMENT CONTENT9. Proce
26、dure9.1 Mix the samples until homogenous, preferably on amechanical shaker. If air bubbles become entrapped in thesample, stir by hand.9.2 Draw approximately5gofthepaint under test into a10-mL syringe and weigh to 1 mg. Transfer, by dropwiseaddition, between 2.0 and 4.0 g of the specimen to a taredp
27、orcelain dish containing either 2 mL of water (for water-bornepaint) or 2 mL of toluene (for solvent-borne paint). Reweighthe syringe to 1 mg. Swirl the dish during the addition of thepaint and continue to swirl until the specimen is completelydispersed. If a water-borne paint tends to agglomerate o
28、r formlumps that cannot be dispersed, a drop or two of concentratedNH4OH may help the dispersement. If the lumps persist,discard the specimen, and prepare a new one. Prepare aduplicate specimen in the same manner.9.3 Dry the specimens at 110C for 30 min and then driveoff the remaining solvent or wat
29、er at the lowest temperaturepossible using a Meker burner (under a hood). Do not leave thedishes on the burners after the flames have subsided.9.4 Transfer the dried specimens to a muffle furnace andheat at 450 6 25C for at least 1 h and until no further char isevident. Leave the furnace door slight
30、ly open after firstinserting the dishes to allow smoke and possibly flames toescape making certain the furnace is well vented.9.5 Remove the dishes from the muffle furnace, cool in adesiccator, and weigh.9.6 Grind the pigment to pass through an 80-mesh screen.10. Calculation10.1 Calculate the percen
31、t pigment content as follows:P 5C 2 W1W23 100 (1)where:3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd.
32、, Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D 4563 02 (2008)2P = pigment content, %C = weight of the dish and specimen after ignition, g,W1= weight of the dish alone, g,W2= specimen weight used, g.11. Preci
33、sion and Bias (see Practice E 180)411.1 In an interlaboratory study of this test method in whichoperators in each of seven laboratories made duplicate analyseson different days and one operator in one laboratory madeduplicate analyses on one day and a single analysis on thesecond day on a water-born
34、e flat wall paint, a solvent-bornesemi-gloss enamel and a solvent-borne house paint containing33, 38.5, and 37 % pigment, respectively, the pooled within-laboratory standard deviation was found to be 0.07 % absolutewith 21 df. The pooled between-laboratories standard deviationwas 0.22 % absolute wit
35、h 21 df. One laboratorys results forone day were discarded because the duplicates differed signifi-cantly and another laboratorys results for one day because therange differed significantly from all other ranges for Coating 1and a third laboratorys results for one day because it differedsignificantl
36、y from the other days results and those from allother laboratories for Coating 2. Based on these standarddeviations the following criteria should be used for judging theacceptability of results at the 95 % confidence level:11.1.1 RepeatabilityTwo results, each the mean of dupli-cates, obtained by th
37、e same operator should be consideredsuspect if they differ by more than 0.21 % absolute at pigmentcontents of 33 to 39 wt %.11.1.2 ReproducibilityTwo results, each the mean of du-plicates obtained by operators in different laboratories, shouldbe considered suspect if they differ by more than 0.66 %a
38、bsolute at the same pigment content levels.TITANIUM DIOXIDE CONTENT12. Procedure12.1 Determine the dry weight of two weighing bottles withcaps. In accordance with Table 1 select the appropriatespecimen weight and place the approximate amount of recov-ered pigment in each weighing bottle.12.2 Dry the
39、 specimens in the open weighing bottles for 2 hat 105C. Cool in a desiccator. After cooling, cap the weighingbottles and weigh as rapidly as possible.12.3 Transfer the dry specimens to 500-mL wide-mouthErlenmeyer flasks. Reweigh bottles and caps and recordweights of specimens transferred (W4in equat
40、ion in 13.1 and13.2).12.4 To the 500-mL flasks, which now contain the speci-mens, add 8 g 6 0.001 g of (NH4)2SO4, 50 mL of concentratedH2SO4and 5 drops of concentrated HNO3. Mix well byswirling the flasks. Heat on a hot plate until dense white fumesare evolved. Continue heating over a hot flame unti
41、l solutionsare complete (usually requires not more than 5 min of boiling),or until it is apparent that the residues are composed of SiO2orsiliceous matter. Cool and add 100 mL of water with extremecaution.12.5 Quantitatively transfer the contents of the flasks in-cluding any insoluble matter to 1000
42、-mL plastic volumetricflasks (see Specification E 288). Add 50 mL of HCl and 30 mLof HF. Allow to cool to room temperature and then fill to themark with water. Stopper and mix well. Transfer the solutionsto plastic bottles (because of the HF) and store for no more than3 months for analysis by AA. So
43、lutions must be filteredthrough a Whatman 42 paper before being aspirated.12.6 Calibrate the instrument in accordance with Section 8and aspirate the solutions in the following order:1water (set to ZERO)2working standard (set to percent TiO2)3specimen (read)1water (set to ZERO)2working standard (set
44、to percent TiO2)3specimen (read)This MUST be repeated until the readings are stable.13. Calculation13.1 Calculate the percent TiO2in the pigment as follows:TiO2,%5C 3 W3W4(2)where:C = reading of specimen (number 3 in 12.6),W3= standard pigment weight in 6.7.1,g,andW4= specimen pigment weight in 12.3
45、,g.13.2 Calculate the percent TiO2in the whole paint asfollows:TiO2%, 5P 3 W33 AW4(3)where:A = pigment calculated in 10.1, %, andP, W3, and W4= same as in 13.1.14. Precision and Bias (see Practice E 180)414.1 In an interlaboratory study of this test method in whichoperators in each of eight laborato
46、ries analyzed on differentdays a water-borne flat wall paint, a solvent-borne semi-glossenamel and a solvent-borne house paint, respectively contain-ing 28.8, 56.8, and 42.8 weight % titanium dioxide in thepigment, the pooled within-laboratory standard deviation wasfound to be 0.65 % absolute with 2
47、2 degrees of freedom. Thepooled between-laboratories standard deviation was 1.31 %4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D01-1046.TABLE 1 Specimen Weight RequirementExpected TiO2onpigment, %Specimen Weight,mgA0 to 19 10
48、0020 to 29 50030 to 39 33040 to 49 25050 to 59 20060 to 69 16070 to 79 14080 to 89 13090 to 100 110AEquivalent to about 60 ppm Ti in the final solution.D 4563 02 (2008)3absolute with 20 degrees of freedom. One duplicate value fromone laboratory was discarded because the range differedsignificantly f
49、rom all other duplicate ranges for Coating 1, onedays result from another laboratory because the range differedsignificantly from all other ranges and both days results froma third laboratory were discarded because the mean differedsignificantly from all other laboratory means for Coating 2, andone duplicate value was discarded from the same laboratory aswith Coating 1 because the range differed significantly from allother duplicate ranges for Coating 3. Based on these standarddeviations, the following criteria should be used for judging theacceptabil
