ASTM E449-2008 752 Standard Test Methods for Analysis of Calcium Chloride《氯化钙分析的标准试验方法》.pdf

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1、Designation: E 449 08Standard Test Methods forAnalysis of Calcium Chloride1This standard is issued under the fixed designation E 449; 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 parenthese

2、s indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 These test methods cover the analysis of calcium chlo-ride and solutions

3、.1.2 Procedures are given for the determination of calciumchloride, magnesium chloride, potassium chloride, sodiumchloride, and calcium hydroxide. The test methods appear inthe following order:SectionsCalcium Chloride 8 to 16Magnesium Chloride, Potassium Chloride,and Sodium Chloride17 to 26Calcium H

4、ydroxide 27 to 331.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.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

5、establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardstatements are given in Section 5.1.5 Review the current Material Safety Data Sheet (MSDS)for detailed information concerning toxicity, first aid proce-dures, ha

6、ndling, and safety precautions.2. Referenced Documents2.1 ASTM Standards:2D 345 Test Method for Sampling and Testing CalciumChloride for Roads and Structural ApplicationsD 1193 Specification for Reagent WaterE 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Indu

7、strial and Spe-cialty ChemicalsE 200 Practice for Preparation, Standardization, and Stor-age of Standard and Reagent Solutions for ChemicalAnalysisE 663 Practice for Flame Atomic Absorption Analysis33. Significance and Use3.1 Calcium chloride is available in various forms andpurities. A major use is

8、 the de-icing and dust control of roads.It is also used in the coal industry for dustproofing andfreezeproofing, in foods, in electrolytic cells, and in refrigera-tion brines. The test methods listed in 1.2 provide proceduresfor analyzing calcium chloride to determine if it is suitable forits intend

9、ed use.4. Reagents4.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, these shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, where suchspecifications are available.4Other grades may be used, p

10、ro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.4.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Type II or Type IIIreagent water conforming to Specificat

11、ion D 1193.5. Hazards5.1 While calcium chloride is a relatively harmless material,some of the reagents used in these methods present possiblesafety hazards. Potassium cyanide is extremely hazardous andmust be handled with great care. In addition to being poison-ous, solutions containing cyanide shou

12、ld never be mixed withacids to preclude the release of poisonous hydrogen cyanidegas. Concentrated hydrochloric acid and sodium hydroxidealso are hazardous chemicals which may produce serious burnson contact.1These test methods are under the jurisdiction of ASTM Committee E15 onIndustrial and Specia

13、lty Chemicals and are the direct responsibility of Subcommit-tee E15.02 on Product Standards.Current edition approved April 1, 2008. Published May 2008. Originallyapproved in 1972. Last previous edition approved in 2001 as E 449 96(2001).2For referenced ASTM standards, visit the ASTM website, www.as

14、tm.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.3Withdrawn.4Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For sug

15、gestions 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. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.1*A Summary of Changes sect

16、ion 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. Atomic Absorption Spectrophotometers6.1 Photometers and photometric practice used in thesemethods shall conform to Practice E 663.7. Sampling7.

17、1 Sampling of calcium chloride is not within the scope ofthese test methods. See the appropriate sections of Test MethodD 345.7.2 The sample to be analyzed shall be considered to be thatsample in a single bottle submitted to the analytical laboratory.7.3 The size of the sample shall be sufficient to

18、 perform allanalyses without the reuse of any portion of the sample.CALCIUM CHLORIDE8. Scope8.1 This test method covers the determination of calciumchloride in the range from 0 to 100 %.9. Summary of Test Method9.1 Calcium in an alkaline solution is titrated with standardethylenediaminetetraacetate

19、solution, using modified calcein IIas an indicator. The color change is from green to purple. a-hydroxynaphthol blue is also suitable as an indicator, in whichcase the color change is from red to blue.10. Interferences10.1 Strontium and other cations not complexed with cya-nide at pH of at least 10

20、will consume ethylenediaminetetraac-etate solution and will affect the accuracy of this test method.11. Apparatus11.1 Buret, 50-mL, Class A.11.2 Weighing Bottle, glass-stoppered, 100-mL.12. Reagents12.1 Calcium Chloride, Standard Solution (1mL = 0.00832 g CaCl2)Weigh 7.500 g of primary standardcalci

21、um carbonate (CaCO3). Transfer to a 600-mL beaker andadd 300 mL of water. Cover with a watch glass and slowly addto the beaker, while stirring, 15 mL of concentrated hydrochlo-ric acid (HCl) delivered from a pipet inserted between the lipof the beaker and the edge of the watch glass. When dissolutio

22、nof the CaCO3is complete, boil gently to expel CO2. Cool, andtransfer to a 1-L volumetric flask. Dilute to volume with waterand mix.12.2 Ethylenediaminetetraacetate, Standard Solution (0.1mol/L (M)Dissolve 37.22 g of disodium dihydrogen ethyl-enediaminetetraacetate dihydrate (EDTA) in water. Transfe

23、r toa 1-L volumetric flask, dilute to volume with water, and mix.Standardize as follows: Transfer a 50-mL aliquot of CaCl2standard solution (1 mL = 0.00832 g CaCl2) to a 500-mLErlenmeyer flask and dilute to 200 mL with water. Proceed asdirected in 13.2. Calculate the CaCl2equivalent of the EDTAsolut

24、ion as follows:Calcium chloride equivalent, g/mL 5 0.416/A (1)where:A = millilitres of EDTAsolution required for the titration ofthe CaCl2solution.12.3 Hydrochloric Acid (1 + 3)Mix 1 volume of concen-trated hydrochloric acid (HCl, sp gr 1.19) and 3 volumes ofwater.12.4 Hydroxylamine Hydrochloride So

25、lution(10 %)Dissolve 10 g of hydroxylamine hydrochloride (NH2OHHCl)in 90 mL of water.12.5 a-Hydroxynaphthol Blue.512.6 Modified Calcein Indicator.612.7 Potassium Cyanide (KCN).12.8 Sodium Hydroxide Solution (80 g/L)Add slowly 80 gof sodium hydroxide (NaOH) in 300 mL of water stirringconstantly. Cool

26、, transfer to a 1-L volumetric flask, dilute tovolume with water, and mix.12.9 Sugar, granulated.13. Procedure13.1 Solid SamplesWeigh 100.0 g of sample and washinto a 1000-mL volumetric flask with water.Add 10 mL of HCl(1 + 3) and swirl to dissolve the sample. Cool to roomtemperature, make to volume

27、 with water, and mix. Pipet a20-mL aliquot into a 500-mL volumetric flask, dilute tovolume, and mix. Proceed as in 13.3.13.2 Liquid SamplesWeigh 100.0 g of sample and washinto a 1000-mL volumetric flask with water.Add 10 mL of HCl(1 + 3) and mix. Cool to room temperature, make up to volumewith water

28、, and mix. Pipet an aliquot containing about2gofCaCl2into a 500-mL volumetric flask, dilute to volume, andmix. Appropriate aliquot volumes are indicated in the tablebelow. Interpolate if necessary.Expected CaCl2Concentration, %AliquotSize, mL10 20020 10030 7540 5050 4013.3 Pipet a 100-mL aliquot of

29、the solution prepared in 13.1or 13.2 into a 500-mL Erlenmeyer flask and dilute to about 200mL with water. Add in order 10 mL of hydroxylaminehydrochloride solution and3gofsugar. Swirl to dissolve. Add40 mL of NaOH solution (12.8) and swirl to mix. Add 0.1 g ofKCN, and swirl to dissolve and mix. Add

30、about 0.2 g ofcalcium indicator.13.4 Titrate with 0.1 M EDTA solution until the indicatorchanges from green to purple.NOTE 1If a-hydroxynaphthol blue indicator is used, 0.4 g should beadded and the solution titrated to a blue end point.14. Calculation14.1 Calculate the calcium chloride concentration

31、 as fol-lows:Calcium chloride, % 5 A 3 B!/C8 3 100 2 D (2)5Available from Mallinckrodt Inc., Paris, KY.6Available from the G. Frederick Smith Co., Columbus, OH.E449082where:A = millilitres of EDTA solution required for titration ofthe sample,B = calcium chloride equivalent of the EDTA solution,g/mL,

32、C8 = mass of sample in the aliquot used, andD = percent calcium hydroxide expressed as calcium chlo-ride (see 31.1.1).15. Report15.1 Report the percentage of CaCl2to the nearest 0.1 %.Duplicate determinations that agree within 0.3 % absolute areacceptable for averaging (95 % confidence level).16. Pr

33、ecision and Bias16.1 The following criteria should be used for judging theacceptability of results (see Note 2).16.1.1 Repeatability (Single Analyst)The standard devia-tion of results (each the average of duplicates), obtained by thesame analyst on different days, has been estimated to be0.139 % abs

34、olute at 28 degrees of freedom. Two such valuesshould be considered suspect (95 % confidence level) if theydiffer by more than 0.4 %.16.1.2 Reproducibility (Multilaboratory)The standard de-viation of results (each the average of duplicates), obtained byanalysts in different laboratories, has been es

35、timated to be0.229 % absolute at 6 degrees of freedom. Two such valuesshould be considered suspect (95 % confidence level) if theydiffer by more then 0.8 % absolute.NOTE 2The precision statements are based on an interlaboratorystudy performed in 1970 on two samples of solid calcium chloride. Eightla

36、boratories participated in the study analyzing each sample in duplicateon each of two days. Practice E 180 was used in developing theseprecision statements.716.2 The bias of the test method has not been determined.MAGNESIUM CHLORIDE, POTASSIUMCHLORIDE, AND SODIUM CHLORIDE17. Scope17.1 This test meth

37、od covers the determination of magne-sium chloride, potassium chloride, and sodium chloride in theranges normally encountered in calcium chloride.18. Summary of Test Method18.1 A solution of the sample is aspirated into the air-acetylene flame of an atomic absorption spectrometer. Theabsorption of a

38、 resonance line from the spectrum of each cationis measured and compared with the response of the instrumentto calibration solutions of the same elements. Recommendedlines are: magnesium (2852 ), potassium (7664 ), andsodium (5889 ).19. Concentration Range19.1 The concentration range for each cation

39、 must beselected to correspond with the optimum range of the instru-ment employed. Higher or lower concentration ranges may berequired for different instruments or different source lamps.20. Interferences20.1 Elements normally present in calcium chloride do notinterfere with these determinations.21.

40、 Apparatus21.1 Atomic Absorption Spectrophotometer, capable of iso-lating the resonance line chosen for each cation sufficiently toavoid interference from other elements in the samples beinganalyzed.22. Reagents22.1 Calcium Chloride SolutionRefer to 12.1.22.2 Hydrochloric Acid (1 + 3)Refer to 12.3.2

41、2.3 Magnesium Chloride, Standard Solution (1mL = 0.050 mg MgCl2)Dissolve 0.128 g of 99.9 % magne-sium metal in 50 mL of HCl (1 + 3) in a covered 250-mLbeaker. Heat gently, if necessary, to complete solution. Cooland transfer to a 1-L volumetric flask. Dilute to volume withwater and mix. Pipet 10.0 m

42、L of this solution into a 100-mLvolumetric flask. Dilute to volume with water and mix.22.4 Potassium Chloride, Standard Solution (1 mL = 0.300mg KCl)Dissolve 0.300 g of potassium chloride (KCl) inwater and dilute to 1 L in a volumetric flask.22.5 Sodium Chloride, Standard Solution (1 mL = 0.100mg Na

43、Cl)Dissolve 1.000 g of sodium chloride (NaCl) inwater and dilute to 1 L in a volumetric flask. Pipet 10.0 mL ofthis solution into a 100-mL volumetric flask. Dilute to volumewith water and mix.23. Procedure23.1 Pipet a 10.0-mLaliquot of the solution prepared in 13.1or 13.2 into a 100-mL volumetric fl

44、ask. Dilute to volume withwater and mix.23.2 To five 100-mL volumetric flasks add 2, 4, 6, 8, and 10mL of each standard solution respectively and 5 mL of CaCl2solution. Dilute to volume with water and mix.23.3 Prepare a zero calibration solution by adding 5 mL ofCaCl2solution to a 100-mL volumetric

45、flask and dilute tovolume with water.23.4 Instrument Settings:23.4.1 Set the instrument parameters to values recom-mended by the manufacturer.23.4.2 Select the proper wavelength for the element to bedetermined and, if appropriate, adjust for maximum response.23.4.3 Optimize fuel, air, and burner adj

46、ustments whileaspirating a calibration solution.23.4.4 When the instrument has operated long enough toattain stability adjust the readout to 100 % transmittance(percent T) or 0 absorbance (percent A) with water. Aspirateand record the readings of the standard samples with a briefwater aspiration aft

47、er each. Repeat the process with sample,standards, sample and again standards, adjusting the zerobetween runs if necessary.7Supporting data are available from ASTM Headquarters, as RR:E15-1015.E44908324. Calculation24.1 Correct the average of the calibration solution readingsby subtracting the avera

48、ge zero calibration solution reading(expressed in absorbance units).24.2 Prepare a calibration curve by plotting the correctedabsorbance values for the calibration solutions versus themicrograms of compound in 100 mL of solution.24.3 Read the micrograms of compound in the samplesolutions from the ca

49、libration curve. Calculate the percentagecompound as follows:Compound, % 5 A/B 3 104(3)where:A = micrograms of compound in 100 mL of sample solu-tion,B = grams of sample in 100 mL of sample solution,percent KCl as percent NaCl = percent KCl 3 0.7839, andpercent alkali chlorides as NaCl = percent NaCl + percentKCl as NaCl.25. Report25.1 Report the percentage of MgCl2to the nearest 0.01 %.Duplicate determinations that agree within 0.01 % absolute areacceptable for averaging (95 % confidence level). See Note 3.25.2 Report the percentage of KCl to the nearest