Designation:E35–88(Reapproved2002)
Standard Test Methods for
Chemical Analysis of Magnesium and Magnesium Alloys1
This standard is issued under thefixed designation E35;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.
1.Scope
1.1These test methods cover the chemical analysis of magnesium and magnesium alloys having chemical composi-tions within the following limits:
Aluminum,%0.5to12
Copper,%0.005to0.1
Iron,%0.002to0.1
Lead,%0.001to0.5
Manganese,%0.01to2.0
Nickel,%0.0005to0.5
Rare earth elements,%0.2to10
Silicon,%0.01to0.8
Thorium,%0.2to25
Tin,%0.5to10
Zinc,%0.3to20
Zirconium,%0.03to1.0
Magnesium,%remainder
1.2The analytical procedures appear in the following order:
Section Aluminum:
Benzoate-Oxinate(Gravimetric)Method8-15
Sodium Hydroxide(Potentiometric)Method
(Optional Routine Method)16-23 Copper:
Neocuproine(Photometric)Method24-33
Hydrobromic Acid-Phosphoric Acid
(Photometric)Method34-43 Iron by the1,10-Phenanthroline(Photometric)
Method44-53
Lead by the Dithizone(Photometric)Method54-63
Magnesium—Analysis for Manganese an-
Zinc by Direct Current Plasma
Spectroscopy(Proposal)2
Manganese by the Periodate(Photometric)
Method64-73
Nickel:
Dimethylglyoxime Extraction(Photometric)
Method74-83
Dimethylglyoxime(Gravimetric)Method84-91
Rare Earth Elements by the Sebacate-
Oxalate(Gravimetric)Method92-98 Silicon:
Perchloric Acid(Gravimetric)Method99-104
Molybdosilicic Acid(Photometric)Method105-114
Thorium by the Benzoate-Oxalate
(Gravimetric)Method115-121 Tin by the Iodine(Volumetric)Method122-129
Zinc:
Ethylenediamine Tetraacetate(Volumetric)
Method130-137
Potassium Ferrocyanide(Volumetric)
Method138-144
Zirconium by the Alizarin Red(Photometric)
Method145-154
体外诊断1.3This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility 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 precau-tions are given in Section5.
2.Referenced Documents
2.1ASTM Standards:
E29Practice for Using Significant Digits in Test Data to Determine Conformance With Specifications3
E30Test Methods for Chemical Analysis of Steel,Cast Iron,Open-Hearth Iron,and Wrought Iron4
E50Practices for Apparatus,Reagents,and Safety Precau-tions for Chemical Analysis of Metals4
E55Practice for Sampling Wrought Nonferrous Metals and Alloys for Determination of Chemical Composition4
E60Practice for Photometric and Spectrophotometric Methods for Chemical Analysis of Metals4prenticehall
E88Practice for Sampling Nonferrous Metals and Alloys in Cast Form for Determination of Chemical Composition4 3.Significance and Use
3.1These test methods for the chemical analysis of metals and alloys are primarily intended to test such materials for compliance with compositional specifications.It is assumed that all who use these test methods will be trained analysts capable of performing common laboratory procedures skill-fully and safely.It is expected that work will be performed in
a properly equipped laboratory.
4.Apparatus,Reagents,and Photometric Practice
4.1Apparatus and reagents required for each determination are listed in separate sections preceding the procedure.The apparatus,standard solutions,and certain other reagents used
1These test methods are under the jurisdiction of ASTM Committee E01on Analytical Chemistry for Metals,Ores,and Related Materials and are the direct
responsibility of Subcommittee E01.04on Aluminum and Magnesium.
神意太极拳Current edition approved Jan.29,1988.Published March1988.Originally published as E35–42.Last previous edition E35–63(1980). 2Appears in the gray pages of the Annual Book of ASTM Standards,V ol03.05.
3Annual Book of ASTM Standards,V ol14.02.
4Annual Book of ASTM Standards,V ol03.05.
1
Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.
in more than one procedure are referred to by number and shall conform to the requirements prescribed in Practices E50, except that photometers shall conform to the requirements prescribed in Practice E60.
4.2The photometric practice prescribed in these test meth-ods shall conform to Practice E60.
5.Safety Precautions
5.1For precautions to be observed in the use of certain reagents in these test methods,reference shall be made to Practices E50.
5.2Because of the reactivity of magnesium with mineral acids,it is recommended that concentrated acids should not be added directly to the alloy,especially in the case offinely divided material.
6.Sampling
6.1Wrought products shall be sampled in accordance with Practice E55.Cast products shall be sampled in accordance with Practice E88.
7.Rounding Calculated Values
7.1Calculated values shall be rounded to the desired num-ber of places in accordance with the rounding method of Practice E29.
ALUMINUM BY THE BENZOATE-OXINATE
(GRA VIMETRIC)TEST METHOD
8.Scope
8.1This test method covers the determination of aluminum in concentrations from0.5to12%.Since this test method is capable of giving very accurate results,it is recommended for referee analysis.
9.Summary of Test Method
9.1Aluminum is precipitatedfirst as the benzoate and then as the oxinate.The latter is dried and weighed.
10.Interferences
10.1No appreciable interference is caused by the ordinary quantities of zinc,manganese,tin,or silicon found in magne-sium alloys.Copper will remain largely insoluble in hydro-chloric acid,the amount going into solution being too small to cause serious interference.Zirconium and thorium would interfere if present,but are not usually encountered in magnesium-aluminum alloys.Zirconium and aluminum are incompatible.Iron can be removed by precipitation from the ammoniacal tartrate solution with hydrogen sulfide just before the precipitation with8-quinolinol.Interference due to minor quantities of iron and cerium can be eliminated by the addition of hydroxylamine hydrochloride prior to the precipitation of the aluminum as the benzoate.
11.Apparatus
11.1Filtering Crucible—A15-mL fritted-glass crucible of medium porosity.Apparatus No.2.
12.Reagents
12.1Ammonium Benzoate Solution(100g/L)—Dissolve 100g of ammonium benzoate in1L of warm water and add1 mg of thymol as a preservative.
12.2Ammonium Tartrate Solution(30g/L)—Dissolve30g of ammonium tartrate in500mL of water,add120mL of NH4OH,and dilute to1L.
12.3Benzoate Wash Solution—To100mL of the ammo-nium benzoate solution,add900mL of warm water and20mL of glacial acetic acid.
12.48–Quinolinol(Oxine)Solution(50g/L)—Dissolve50
g of8-quinolinol in120mL of glacial acetic acid and dilute to 1L.Filter and store in a dark bottle.
13.Procedure
13.1Weigh,to the nearest1mg,a portion of the sample calculated to contain0.2to0.3g of aluminum an
d transfer to a400-mL beaker containing50mL of water.Dissolve the sample by adding,in small portions,a total of10mL of HCl per gram of sample.When dissolved,cool to room temperature and dilute to500mL in a volumetricflask.Any residue of undissolved silica,which might contain some occluded alumi-num,should be kept in suspension.
13.2Pipet a50.0-mL aliquot into a400-mL beaker and dilute to100mL.Neutralize the solution with NH4OH(1+1) by adding dropwise with stirring until the precipitate that forms as each drop strikesfinally redissolves only very slowly;that is,until nearly all of the free acid is neutralized without permanent precipitation of Al(OH)3.Add1mL of glacial acetic acid,about1g of NH4Cl,and20mL of ammonium benzoate solution.Heat the mixture to boiling while stirring, keep at gentle boiling for5min,and thenfilter on a medium paper.Wash the precipitate eight to ten times with hot benzoate wash solution,making no effort to transfer all of the precipitate to thefilter paper.
核磁共振氢谱13.3Dissolve the precipitate withfive10-mL portions of hot ammonium tartrate solution,washing with hot water after each portion is added.Collect the solution in the original beaker and dilute to150to200mL.Heat the solution to70to 90°C,add20mL of8-quinolinol solution,and digest for15 min without boiling.Filter the solution through a tared, fritted-glass crucible,and wash eight times with hot water, transferring all of the precipitate.
13.4Dry the precipitate for2h at120to130°C,cool,and weigh as aluminum oxinate(Al(C9H6ON)3).
14.Calculation
14.1Calculate the percentage of aluminum as follows:
Aluminum,%5@~A30.0587!/B#3100(1) where:
A=aluminum oxinate,g,and
B=sample in aliquot used,g.
15.Precision and Bias
15.1This test method was originally approved for publica-tion before the inclusion of precision and bias statements within standards was mandated.The original interlaboratory test data is no longer available.The user is cautioned to verify by the use of reference materials,if available,that the precision and bias of this test method is adequate for the contemplated
use.
ALUMINUM BY THE SODIUM HYDROXIDE (POTENTIOMETRIC)TEST METHOD
(Optional Rapid Method)
16.Scope
16.1This test method covers the rapid determination of aluminum in concentrations from2to12%.For referee analysis,the method described in Sections8-15shall be used.
17.Summary of Test Method
17.1The sample is dissolved in hydrochloric acid,the excess acid is partially neutralized with ammonium hydroxide (1+2),and the neutralization is completed with1N sodium hydroxide solution to afinal potentiometric end point.Alumi-num is then titrated with1N sodium hydroxide solution to a final potentiometric end point.
18.Interferences
18.1Bismuth interferes with the potential changes of the antimony electrode and may be removed,if present,by precipitation with hydrogen sulfide and explusion of excess hydrogen sulfide by boiling before titration.Copper and silver lower the potentials of the end points but do not interfere with the deflections.The presence of abnormal amounts of dis-solved silicic acid and ferric iron cause high results.Ceric cerium,thorium,zirconium,titanium,and tin must be absent. Zinc,cadmium,nickel,and manganese do not interfere. 19.Apparatus
19.1Apparatus for Potentiometric Titration—Apparatus No.3B.The titration assembly shall consist of an antimony electrode and a saturated calomel electrode with a potassium chloride salt bridge terminating in a porous-glass or porcelain plug.These shall dip into a titration beaker,which shall be provided with a thermometer and a mechanical stirrer and be mounted on a support in such a way that the beaker can be heated.
20.Reagents
20.1Bromophenol Blue Indicator Solution(4g/L)—Place 0.40g of bromophenol blue in a mortar,add8.25mL of sodium hydroxide solution(5g NaOH per litre),and mix until solution is complete.Dilute to100mL with water and mix.
20.2Indicator-Buffer Solution—Add8mL of bromophenol blue indicator solution to1L of saturated NH4Cl solution. 20.3Sodium Hydroxide,Standard Solution(1N)—See Reagent No.16.
21.Procedure
21.1Weigh,to the nearest1mg,a portion of the sample calculated to contain approximately0.15g of aluminum and place it in a250-mL beaker containing50mL of water.Add,in small portions,7.5mL of HCl per gram of sample,and then1 mL in excess.
21.2When the dissolution is complete,cool to room tem-perature and add20mL of the indicator-buffer solution.Place the beaker in the titration assembly,start the stirrer,and titrate the excess acid with dropwise additions of NH4OH(1+2) until the potentiometer shows a rapid increase in deflection.Continue titrating with1N NaOH solution,using two-drop increments,to thefirst potentiometric break,shown by a maximum deflection at a potential of150to190mV and occurring very nearly at the color change from yellow to blue.
21.3Heat the solution to80°C and,while maintaining the temperature of the solution at this level,titrate again with1N NaOH solution to a second end point as shown by a maximum deflection occurring at a potential of275to300mV.
N OTE1—The reaction upon which this titration is based is believed to be as follows:
2AlCl315NaOH→Al2~OH!5Cl15NaCl(2) 22.Calculation
22.1Calculate the percentage of aluminum as follows:
Aluminum,%5@~AB30.0108!/C#3100(3) where:
A=NaOH solution required for titration of the sample from thefirst to the second potentiometric end point,
mm,
B=normality of the NaOH solution,and
范立欣
C=sample used,g.
23.Precision and Bias
23.1This test method was originally approved for publica-tion before the inclusion of precision and bias statements within standards was mandated.The original interlaboratory test data is no longer av
ailable.The user is cautioned to verify by the use of reference materials,if available,that the precision and bias of this test method is adequate for the contemplated use.
COPPER BY THE NEOCUPROINE(PHOTOMETRIC)
TEST METHOD
24.Scope
24.1This test method covers the determination of copper in concentrations under0.05%.
25.Summary of Test Method
25.1Cuprous copper is separated from other metals by extraction of the neocuproine complex with chloroform.Pho-tometric measurement is made at approximately455nm. 26.Concentration Range
26.1The recommended concentration range is from0.005 to0.05mg of copper in50mL of solution,using a cell depth of5cm.
N OTE2—This test method has been written for cells having a5-cm light path.Cells having other dim
ensions may be used,provided suitable adjustments can be made in the amounts of sample and reagents used.
27.Stability of Color
27.1The color develops in an aqueous media within5min, and the extracted complex is stable for at least a week.
28.Interferences
28.1The elements ordinarily present in magnesium alloys do not interfere if their contents are under the maximum limits shown in
1.2.
29.Reagents
29.1Chloroform.
29.2Copper,Standard Solution(1mL=0.01mg Cu)—Dissolve0.2000g of copper in15mL of water and3mL of HNO3.When dissolution is complete,boil out all nitrogen oxide fumes,cool,and dilute to1L with water.Pipet50mL of this solution into another1-Lflask and dilute to volume with water.
29.3Hydrogen Peroxide(30%)—Concentrated hydrogen peroxide(H2O2).
29.4Hydroxylamine Hydrochloride Solution(100g/L)—Dissolve10g of hydroxylamine hydrochloride(NH2OH·HCl) in water and dilute to100mL.
29.5Neocuproine Solution(1g/L)—Dissolve50mg of 2,9-dimethyl-1,10-phenanthroline hemihydrate in50mL of absolute ethyl alcohol.
29.6Sodium Citrate Solution(100g/L)—Dissolve100g of sodium citrate dihydrate in water and dilute to1L.
30.Preparation of Calibration Curve
30.1Calibration Solutions—Transfer0.5,1.0,2.0,3.0,and 5.0mL of copper solution(1mL=0.01mg Cu)to
100-mL beakers.Dilute to approximately40mL and add HCl until the solution is acid to congo red paper.Proceed in accordance with 30.3.
30.2Reference Solution—Transfer40mL of water to a 100-mL beaker and add HCl until the solution is acid to congo red paper.Proceed in accordance with30.3.
30.3Color Development:
30.3.1Add5.0mL of hydroxylamine hydrochloride solu-tion and stir.Add5.0mL of sodium citrate solution and swirl. Neutralize the solution with NH4OH(1+1)until it is definitely alkaline to congo red paper.Add4.0mL of the neocuproine solution,stir,and allow to stand for5min.
30.3.2Transfer the solution to a250-mL separatory funnel and add20mL of chloroform.Shake the mixture and allow the layers to separate.Place a glass wool plug that has been washed with chloroform in a small funnel andfilter the organic layer,catching thefiltrate in a dry50-mL volumetricflask.
30.3.3Add another millilitre of the neocuproine solution to the separatory funnel,shake,and re-extract with20mL of chloroform.Filter the organic layer into the volumetricflask and dilute to volume with chloroform.
30.4Photometry—Transfer a suitable portion of the refer-ence solution to an absorption cell with a5-cm light path and adjust the photometer to the initial setting using a light band centered at approximately455nm.While maintaining this adjustment,take the photometric readings of the calibration solutions.
30.5Calibration Curve—Plot the photometric readings of the calibration solutions against milligrams of copper per50 mL of solution.
31.Procedure
31.1Test Solution—Weigh,to the nearest1mg,a portion of the sample calculated to contain from0.005to0.05mg of copper and transfer it to a100-mL beaker.Add25mL of water and dissolve the sample by adding small portions of HCl.(Use 7.5mL of HCl per gram of sample.)When dissolution is complete(Note3),add a few drops of hydrogen peroxide solution,boil to remove excess peroxide,cool,and dilute to approximately40mL.
N OTE3—In case there is insoluble material remaining,filter the solution and treat the residue with HF to eliminate silica.Fuse any remaining residue with potassium bisulfate(KHSO
4
)and add the dis-solved melt to the originalfiltrate.
31.2Reference Solution—Transfer40mL of water to a 100-mL beaker and add HCl until the solution is acid to congo red paper.
31.3Color Development—Develop the color as described in30.3.
31.4Photometry—Take the photometric reading of the test solution in accordance with30.4.
32.Calculation
32.1Convert the photometric reading of the test solution to milligrams of copper by means of the calibration curve. Calculate the percentage of copper as follows:
Copper,%5A/~B310!(4) where:
A=copper found,mg,and
B=sample used,g.
33.Precision and Bias
33.1This test method was originally approved for publica-tion before the inclusion of precision and bias statements within standards was mandated.The original interlaboratory test data for this test method are no longer available.The user is cautioned to verify by the use of reference materials,if available,that the precision and bias of this test method are adequate for the contemplated use.
COPPER BY THE HYDROBROMIC ACID-
PHOSPHORIC ACID(PHOTOMETRIC)TEST
METHOD
34.Scope
34.1This test method covers the determination of copper in concentrations from0.005to0.1%.
35.Summary of Test Method
35.1Cupric copper forms a violet-colored complex in strong hydrobromic acid solution.Phosphoric acid is added to minimize interference from iron.Photometric measurement is made at approximately600nm.
36.Concentration Range
36.1The recommended concentration range is from0.05to 0.6mg of copper per25mL of solution,using a cell depth of 1cm.
N OTE4—This test method has been written for cells having a1-cm light path.Cells having other dimensions may be used,provided suitable adjustments can be made in the amounts of sample and reagents used.
37.Stability of Color
37.1The color is stable for at least2
h.
38.Interferences
38.1The elements ordinarily present in magnesium alloys do not interfere if their contents are under the maximum limits shown in 1.1.Molybdenum,vanadium,chromium,cobalt, gold,the platinum metals,and certain elements of the rare earth group would cause interference,if present.Iron or nickel may cause somewhat high results if present in an amount equaling or exceeding the amount of copper.Provision is made in the test method for separation of copper from all elements but the noble metals.
39.Reagents
39.1Bromine Water(saturated).
39.2Copper,Standard Solution(1mL=0.02mg Cu)—Dissolve0.2000g of“pure”copper in15mL of HBr containing1mL of bromine(Br2)and dilute to250mL in a volumetricflask.Dilute25mL of this solution to1L in a volumetricflask.
39.3Hydrobromic Acid-Bromine Solution—Add1drop of bromine to250mL of HBr and mix.
40.Preparation of Calibration Curve
40.1Calibration Solutions—Transfer2.0,5.0,10.0,20.0, and30.0mL of copper solution(1mL=0.02mg C
u)to 100-mL beakers.
40.2Reference Solution—Prepare a reagent blank,using the same amounts of all reagents,to be used as a reference solution.
40.3Color Development—Add enough bromine water, dropwise,to produce a yellow color,and then add3mL of
HBr-Br
2solution.Evaporate the solution to3mL,or slightly
less,and cool.Add3mL of HBr-Br2solution plus12.5mL of H3PO4and transfer the solution to a25-mL,glass-stoppered volumetricflask.Rinse the beaker with small portions of HBr-Br2solution and add these washings to theflask.Dilute to volume with the HBr-Br2solution.
40.4Photometry—Transfer a suitable portion of the refer-ence solution to an absorption cell with a1-cm light path and adjust the photometer to the initial setting,using a light band centered at approximately600nm.While maintaining this adjustment,take the photometric readings of the calibration solutions.
40.5Calibration Curve—Plot the photometric readings of the calibration solutions against milligrams of copper per25 mL of solution.
41.Procedure
41.1Test Solution—Weigh,to the nearest1mg,a portion of the sample of not more than1g containing from0.1to1.2mg of copper,but with no more iron or nickel than copper(Note5). Transfer to a100-mL beaker and add25mL of water.Treat with HBr-Br2solution,adding it in small portions and using a total of10mL per gram of sample plus an excess of3mL. Warm to dissolve all the metal,adding a little bromine water if necessary.Cool,transfer to a50-mL volumetricflask,and dilute to volume with water.Pipet a25-mL aliquot into a 100-mL beaker.
N OTE5—To remove iron or nickel,transfer0.5to1.0g of the sample to a250-mL beaker containing25mL of water and treat with small portions of HCl(2+3)until a total of25mL per gram of sample has been added.After the reaction subsides,add a few drops of H2O2to facilitate the solution of all the copper.Boil the solution to remove chlorine,dilute to about50mL,and add1g offinely granulated,low-copper lead.Bring the solution to a boil and continue gentle boiling for15min to displace the copper completely.Cool,and decant the solution,washing once with water.(If desired,this
solution may be placed in a separatory funnel and used for the determination of nickel by the dimethyl-glyoxime photomet-ric method.)Warm the beaker containing the lead and copper gently to remove moisture;then dissolve the metal in10mL of HBr-Br
2
solution and a few drops of liquid bromine.Boil to expel the bromine.Cool, transfer to a50-mL volumetricflask,and dilute to volume with water. Pipet a25-mL aliquot into a100-mL beaker and proceed in accordance with41.3.
41.2Reference Solution—Prepare a reagent blank,using the same amounts of all reagents,for use as a reference solution.
41.3Color Development—Develop the color as described in40.3.Filter off any insoluble material on a dry,fritted-glass crucible.
41.4Photometry—Take the photometric reading of the test solution in accordance with40.4.
42.Calculation
42.1Convert the photometric reading of the test solution to milligrams of copper by means of the calibration curve. Calculate the percentage of copper as follows:
Copper,%5A/~B310!(5) where:
A=copper found in25mL of thefinal solution,mg,and B=sample represented in25mL of thefinal solution,g. .
43.Precision and Bias
43.1This test method was originally approved for publica-tion before the inclusion of precision and bias statements within standards was mandated.The original interlaboratory test data for this test method are no longer available.The user is cautioned to verify by the use of reference materials,if available,that the precision and bias of this test method are adequate for the contemplated use.
IRON BY THE1,10-PHENANTHROLINE
(PHOTOMETRIC)
TEST METHOD
44.Scope
44.1This test method covers the determination of iron in concentrations under0.1%.Larger percentages may be deter-mined by taking an aliquot portion of the sample.
45.Summary of Test Method
深圳职业技术学院图书馆
45.1Ferrous iron,in a solution having a pH of about5, forms an orange-red complex with1,10-phenanthroline.Pho-tometric measurement is made at approximately510nm.
N OTE6—If desired,a1%alcoholic solution of2,28-bipyridine may be used for color development.Photometric measurement should be made at approximately520nm.
46.Concentration Range
46.1The recommended concentration ranges are from
0.01
