1、Designation: D2087 06 (Reapproved 2012)Standard Test Method forIron in Formaldehyde Solutions1This standard is issued under the fixed designation D2087; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber 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 determination of the totaliron content of formaldehyde solutions.1.2 For purposes of determining conformanc
3、e of an ob-served or a calculated value using this test method to relevantspecifications, test result(s) shall be rounded off “to the nearestunit” in the last right-hand digit used in expressing thespecification limit, in accordance with the rounding-off methodof Practice E29.1.3 The values stated i
4、n SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 For hazard information and guidance, see the suppliersMaterial Safety Data Sheet.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is th
5、eresponsibility 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.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test
6、 Data toDetermine Conformance with Specifications3. Summary of Test Method3.1 The specimen is evaporated and ashed; the iron, reducedto the divalent state by the addition of hydroxylamine hydro-chloride, is reacted with o-phenanthroline to develop a colorthat is measured at 510 nm.4. Significance an
7、d Use4.1 This test method provides a measurement of iron con-tent of formaldehyde solutions. The results of these measure-ments can be used for specification acceptance.5. Apparatus5.1 Spectrophotometer, capable of measuring light absorp-tion at 510 nm.5.2 Absorption Cells, minimum light path, 10 mm
8、.5.3 Evaporating Dishes, 90-mm diameter, high-silica glass.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the
9、 American Chemical Society,where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencest
10、o water shall be understood to mean reagent water as definedby Type IV of Specification D1193.6.3 Ammonium Acetate Solution (100 g/L)Dissolve 100 gof ammonium acetate (NH4C2H3O2) in 100 mL of water. Add200 mL of acetic acid (CH3COOH), dilute to 1 L with water,and mix.6.4 Ammonium Hydroxide (1 + 1)Mi
11、x equal volumes ofconcentrated ammonium hydroxide (NH4OH, sp gr 0.90) andwater.6.5 Congo Red Paper.6.6 Hydrochloric Acid (1 + 1)Mix equal volumes of con-centrated hydrochloric acid (HCl, sp gr 1.19) and water.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coati
12、ngs, Materials, and Applications and is the direct responsibility ofSubcommittee D01.35 on Solvents, Plasticizers, and Chemical Intermediates.Current edition approved June 1, 2012. Published July 2012. Originally approvedin 1962. Last previous edition approved in 2006 as D2087 06. DOI: 10.1520/D2087
13、-06R12.2For referenced ASTM standards, visit 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.3Reagent Chemicals, American Chemical Society Specific
14、ations, AmericanChemical 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 Conventio
15、n, Inc. (USPC), Rockville,MD.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16.7 Hydroxylamine Hydrochloride Solution (100 g/L)Dissolve 10 g of hydroxylamine hydrochlori
16、de (NH2OHHCl) in water and dilute to 100 mL.6.8 Iron, Standard Solution (1 mL = 0.05 mg Fe)Dissolve0.3510 g of ferrous ammonium sulfate (FeSO4(NH4)2SO46H2O) in 50 mL of water and 20 mL of concen-trated sulfuric acid (H2SO4, sp gr 1.84). Dilute with water to 1L in a volumetric flask and mix.6.9 o-Phe
17、nanthroline Solution (1 g/L)Dissolve 0.1 g ofo-phenanthroline in 10 mL of iron-free ethyl alcohol4anddilute to 100 mL with water.7. Calibration7.1 Prepare a series of standards by adding the reagentsdescribed in 6.3 to 0.2, 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0-mL ofstandard iron solution in 100-mL volum
18、etric flasks, and dilut-ing to volume.7.2 Make spectrophotometer comparisons in the absorptioncells and prepare a calibration curve by plotting the absor-bances of the standard iron solutions against the milligrams ofiron per 100 mL of solution. This curve must be determined foreach instrument and s
19、hould be checked periodically.8. Procedure8.1 Clean a high-silica glass evaporating dish as follows:Add 10 mL of HCl (1 + 1), cover with a watch glass, and digeston a steam bath for about 20 min. Then discard the HClsolution, rinse the dish with water, and dry.8.2 Weigh 50 g of sample into the clean
20、ed dish andevaporate to dryness on an electric hot plate in a hood. If anyorganic matter remains, ignite for 5 min over a high-temperature gas burner.8.3 Add 10 mLof HCl (1 + 1), cover with a watch glass, anddigest on the steam bath for 15 min. Transfer quantitatively toa 100-mL volumetric flask. Ad
21、d the following reagents inorder, mixing after the addition of each: 1 mL of NH2OHHClsolution, 5 mL of o-phenanthroline solution, enough NH4OH(1 + 1) as required to make the solution just alkaline to Congored paper (approximate pH range 3.0 to 5.0), and 5 mL ofNH4C2H3O2solution. Dilute to the mark w
22、ith water and mixthoroughly.8.4 Allow to stand for 5 min, fill an absorption cell, andmeasure the absorbance at 510 nm with the spectrophotometer.From the calibration curve, read the milligrams of iron present.8.5 Carry a blank containing no added iron through all stepsof the procedure in order to c
23、orrect for any iron contaminationin the reagents. Correct the results obtained in 8.4 accordingly.9. Calculation9.1 Calculate the parts per million of iron I as follows:I 5 W/S! 31000where:W = weight, of iron found mg, andS = weight of sample used, g.10. Report10.1 Report the mass of iron to the nea
24、rest parts per million.11. Precision and Bias11.1 RepeatabilityThe difference between two determina-tions by the same operator is normally about 0.6 ppm. Twosuch results should be considered suspect if they differ by morethan 0.16 ppm.11.2 ReproducibilityThe difference between two resultsobtained by
25、 operators in different laboratories is normallyabout 0.11 ppm. Two such results should be considered suspectif they differ by more than 0.3 ppm.11.3 BiasBias cannot be determined for this test methodbecause there is no material having an accepted referencevalue.12. Keywords12.1 formaldehyde solutio
26、ns; ironSUMMARY OF CHANGESCommittee D01.35 has identified the location of selected changes to this standard since the last issue(D2087 97 (2001) that may impact the use of this standard.(1) Added reference to Practice E29 in the Scope section. (2) Added Practice E29 to list of Referenced Documents.4
27、Specially denatured ethyl alcohol conforming to Formula No. 30 of the U. S.Treasury Department, Bureau of Industrial Alcohol has been found satisfactory forthis purpose.D2087 06 (2012)2ASTM International takes no position respecting the validity of any patent rights asserted in connection with any i
28、tem mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical co
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30、 meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Dri
31、ve, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D2087 06 (2012)3
