1、Designation: D 2087 06Standard Test Method forIron in Formaldehyde Solutions1This standard is issued under the fixed designation D 2087; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenth
2、eses 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 determination of the totaliron content of formaldehyde solutions.1.2 For purposes of determining conformance of an ob-serv
3、ed 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 E 29.1.3 The values stated in SI units are
4、 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 theresponsibilit
5、y 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:2D 1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test Data toDeter
6、mine 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 and Use4.1 This
7、 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.5.3 Evaporat
8、ing 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 American Che
9、mical 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, referencesto water shall
10、 be understood to mean reagent water as definedby Type IV of Specification D 1193.6.3 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)Mix equal volu
11、mes 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.6.7 Hydroxylamine Hydrochloride Solution (100 g/L)Dissolve 10 g of hydroxylamine hydrochloride (NH2OHHC
12、l) 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.1This test method is
13、 under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.35 on Solvents, Plasticizers, and Chemical Intermediates.Current edition approved April 1, 2006. Published April 2006. Originallyapproved in 196
14、2. Last previous edition approved in 2001 as D 2087 97 (2001).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
15、.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., Poole, Dorset, U.K., and the United States Pharmacop
16、eiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.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.6.9 o-Phenanthroline Solution (1 g/
17、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 volumetric flasks, and dilut-in
18、g 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 should be checked periodica
19、lly.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 cleaned dish andevaporate to dr
20、yness 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. Add the following reagents i
21、norder, 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 with water and mixthoroughl
22、y.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 correct for any iron contam
23、inationin 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! 3 1000where:W = weight, of iron found mg, andS = weight of sample used, g.10. Report10.1 Report the mass of iron to the nearest parts per million.11
24、. 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 operators in different l
25、aboratories 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 solutions; ironSUMMARY OF CHANGE
26、SCommittee D01.35 has identified the location of selected changes to this standard since the last issue(D 2087 97 (2001) that may impact the use of this standard.(1) Added reference to Practice E29in the Scope section. (2) Added Practice E29to list of Referenced Documents.ASTM International takes no
27、 position respecting the validity of any patent rights asserted in connection with any item 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 respons
28、ibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed t
29、o ASTM International Headquarters. Your comments will receive careful consideration at a 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 add
30、ress shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, 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).4Specially denatured ethyl alcohol conforming to Formula No. 30 of the U. S.Treasury Department, Bureau of Industrial Alcohol has been found satisfactory forthis purpose.D2087062
