ASTM D1385-2007 Standard Test Method for Hydrazine in Water《水中联氨的标准试验方法》.pdf

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1、Designation: D 1385 07An American National StandardStandard Test Method forHydrazine in Water1This standard is issued under the fixed designation D 1385; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A

2、number in parentheses 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. Scope1.1 This test method covers2the colorimetric determinatio

3、nof hydrazine in boiler feed waters, condensates, natural, andwell waters that have been treated with hydrazine (N2H4). Thistest method is usable in the range from 5.0 to 200 g/L (ppb)hydrazine. The range is for photometric measurements made at458 nm in 50 mm cell. Higher concentrations of hydrazine

4、 canalso be determined by taking a more diluted sample.1.2 It is the users responsibility to ensure the validity of thistest method for untested types of waters.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the us

5、er of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specificprecautionary statements, see 5.3, Note 1, and Footnote 8.2. Referenced Documents2.1 ASTM Standards:3D 1066 Practice for Sampling SteamD 1129

6、 Terminology Relating to WaterD 1193 Specification for Reagent WaterD 3370 Practices for Sampling Water from Closed ConduitsD 5810 Guide for Spiking into Aqueous SamplesD 5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisE60 Practice for Analysis of

7、Metals, Ores, and RelatedMaterials by Molecular Absorption SpectrometryE 275 Practice for Describing and Measuring Performanceof Ultraviolet, Visible, and Near-Infrared Spectrophotom-eters3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D 1129.4. Su

8、mmary of Test Method4.1 When a solution of p-dimethylaminobenzaldehyde inmethyl alcohol and hydrochloric acid is added to hydrazine indiluted hydrochloric acid solution, a characteristic yellow colorof p-dimethylaminobenzalazine is formed. The yellow colorformed is proportional to the hydrazine pres

9、ent and is in goodagreement with Beers law in the range from 5.0 to 200 g/L(ppb) hydrazine.5. Significance and Use5.1 Hydrazine is a man-made chemical and is not found innatural waters. The determination of hydrazine is usually madeon boiler feedwaters, process waters, and other waters thathave been

10、 treated with hydrazine (N2H4) for the purpose ofmaintaining residuals to prevent corrosion by dissolved oxy-gen. This reducing chemical reacts with dissolved oxygen toform nitrogen and water. However, under certain conditions itcan also decompose to form ammonia and nitrogen. Hydrazineis used exten

11、sively as a preboiler treatment chemical forhigh-pressure boilers to scavenge small amounts of dissolvedoxygen that are not removed by mechanical aeration. It has theadvantage over sulfite treatment in that it does not produce anydissolved solids in the boiler water. Hydrazine is often deter-mined i

12、n concentrations below 0.1 mg/L. However, in layupsolutions for the protection of idle boilers, hydrazine may bepresent in concentrations as high as 200 mg/L.5.2 Additionally, hydrazine provides protection where re-ducing conditions are required, particularly in mixed metal-lurgy systems for the pro

13、tection of the copper alloys.5.3 Hydrazine is a suspected carcinogen and a thresholdlimit value in the atmosphere of 1.0 mg/L has been set byOSHA. When in an aqueous solution, hydrazine will oxidize tonitrogen and water in the presence of air over a relatively shortperiod of time.1This test method i

14、s under the jurisdiction of ASTM Committee D19 on Waterand is the responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits, Analysis of Water for Power Generation and Process Use,On-Line Water Analysis, and Surveillance of Water.Current edition approved June 15, 2007. Publish

15、ed July 2007. Originallyapproved in 1967. Last previous edition approved in 2001 as D 1385 01.2For further information on this test method, the following references may be ofinterest: Watt, G. W., and Chrisp, J. D., “Spectrophotometric Method for theDetermination of Hydrazine,” Analytical Chemistry,

16、 Vol 24, No. 12, 1952, pp.20062008, and Wood, P. R., “Determination of Maleic Hydrazide Residues in Plantand Animal Tissue,” Analytical Chemistry, Vol 25, No. 12, 1953, pp. 18791883.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.o

17、rg. 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.6. Interferences6.1 The substances normally present in industria

18、l water donot interfere with the test; however, the hydrazine content maybe diminished by oxidizing agents, such as chlorine, bromine,and iodine, collected with the sample or absorbed by it prior totesting.6.2 Colors in the prescribed wavelengths also interfere, asdo other dark colors or turbidities

19、 that cannot be overcome.6.3 Aromatic amines, such as aniline, will also interfere.7. Apparatus7.1 PhotometerA spectrophotometer suitable for mea-surements at 458 nm and capable of holding cells with a lightpath of 50 mm should be used. Filter photometers andphotometric practices prescribed in this

20、test method shallconform to Practice E60, and spectrophotometers to PracticeE 275.7.2 Certain photoelectric filter photometers are capable ofmeasurement at 425 nm, but not at 458 nm. Measurements maybe made at 425 nm with a reduction in sensitivity of approxi-mately 50 % of that possible at 458 nm.7

21、.3 Instruments that read out in direct concentration can alsobe used. Manufacturers instructions should be followed.8. Reagents8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of t

22、he Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent issufficiently high in purity to permit its use without lesseningthe accuracy of the determinations.8.2 Purity of

23、WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto the requirements in Specification D 1193, Type III.8.3 Hydrazine Solution, Stock (1.0 mL = 100 g N2H4)Dissolve 0.328 g of hydrazine dihydrochloride (HClNH2NH2HCl) in 100 mL of water and 10 mL o

24、f HCl (sp gr 1.19).Dilute with water to 1 L in a volumetric flask and mix(Warning, see Note 1).8.4 Hydrazine Solution, Standard (1.0 mL = 0.500 gN2H4)Dilute 5.0 mL of hydrazine stock solution to 1 L withwater and mix. Prepare as needed.NOTE 1Warning: Hydrazine is a suspected carcinogen and should be

25、handled with care.58.5 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).8.6 p-Dimethylaminobenzaldehyde SolutionDissolve 4.0g of p-dimethylaminobenzaldehyde (CH3)2NC6H4CHO in200 mL of methyl alcohol (CH3OH) and 20 mL of HCl (sp gr1.19). Store in a dark bottle out of direct sunligh

26、t.9. Sampling9.1 Collect the sample in accordance with Practices D 3370or Practice D 1066, whichever is applicable (Warning, seeNote 1).9.2 Acidify and dilute the sample as soon as taken by adding1 mL of concentrated HCl (sp gr 1.19) to a 100-mL volumetricflask and then pipetting 50 mL of the sample

27、 into the flask anddiluting to 100 mL. Prepare a blank with water at the sametime.9.3 A smaller sample aliquot should be taken if the hydra-zine concentration is greater than 200 g/L.10. Calibration10.1 Prepare a series of standard hydrazine solutions bypipetting 0.0, 5.0, 10.0, 25.0, 50.0, 100.0, a

28、nd 200.0 mL ofhydrazine standard solution (1.0 mL = 0.500 g N2H4) into500-mL volumetric flasks. Add 5 mL of HCl (sp gr 1.19) toeach flask and dilute with water to 500 mL and mix well. Thiswill give standard solutions containing 0, 5.0, 10.0, 25.0, 50.0,100, and 200 g/L (ppb) of hydrazine.10.2 Pipet

29、50.0-mL portions of the hydrazine standardsolutions into clean, dry 100-mL beakers or flasks and proceedas directed in 11.2. Plot absorbance on the ordinate andmicrograms per litre of hydrazine on the abscissa of lineargraph paper.10.3 A separate calibration curve must be made for eachphotometer and

30、 a recalibration must be made if it is necessaryto change the cell, lamp, or filter, or if any other alterations ofinstrument or reagents are made. Check the curve for eachseries of tests by running two or more solutions of knownhydrazine concentrations.11. Procedure11.1 Pipet 50.0 mL of the blank,

31、standard solutions, andacidified diluted sample solutions into clean, dry 100-mLbeakers or flasks.11.2 Add 10.0 mL of p-dimethylaminobenzaldehyde solu-tion with a pipet to each beaker or flask and mix well.11.3 After a minimum of 10 min, but no longer than 100min, measure the color absorbance of eac

32、h solution at 458 nmin a 50 mm cell with a spectrophotometer, using the blank asreference solution for the initial instrument setting at zeroabsorbance. The instrument may be calibrated with the stan-dard solutions to read directly in concentration if such capa-bilities are available.11.4 Determine

33、the micrograms per litre of hydrazine byreferring the absorbance obtained for the sample to thecalibration curve or reading hydrazine concentration directly.12. Calculation12.1 Calculate the concentration of hydrazine in micro-grams per litre (parts per billion) in the sample by applying thefollowin

34、g equation for the hydrazine determined in 11.4:4Reagent 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

35、, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.5MacEwen, J. D., Vernot, E. H., Haun, C. C., and Kinkead, E. B., “ChronicInhalation Toxicity of Hydrazine: Onconogenic Effects,” in cooperation with theUniversity of Cal

36、ifornia (Irvine) and the Airforce Aero Medical Research Labora-tory.D 1385 072hydrazine N2H4!, g/L ppb!5A B/Cwhere:A = hydrazine indicated by the calibration curve or readdirectly from the instrument, g/L,B = volume of the flask, g/L, in which the sample wasdiluted in Section 9.2, mL, andC = volume

37、of the sample in Section 9.2, mL.13. Precision and Bias613.1 The precision of this test method was tested by seven(7) laboratories in reagent water, condensate, well water, andnatural water. Three laboratories reported data from twooperators. Although multiple injections were reportedly made,the rep

38、ort sheets that were provided allowed only for reportingsingle values. Thus, no single operator precision can becalculated.13.1.1 The overall precision of this test method, within itsdesignated range for both reagent water and selected naturalwater matrices, varies with the quantity tested, as shown

39、 in Fig.1.13.1.2 Recovery and bias data for this test method are listedin Table 1.13.2 These data may not apply to waters of other matrices;therefore, it is the responsibility of the analyst to ensure thevalidity of the test method in a particular matrix.14. Quality Control14.1 In order to be certai

40、n that analytical values obtainedusing this test method are valid and accurate within theconfidence limits of the test, the following QC procedures mustbe followed when running the test.14.2 Calibration and Calibration Verification14.2.1 When beginning use of this method, an initial cali-bration ver

41、ification standard (CVS) should be used to verify thecalibration standards and acceptable instrument performance.This verification should be performed on each analysis day.The CVS is a solution of the method analyte of knownconcentration (mid-calibration range) used to fortify reagentwater. If the d

42、etermined CVS concentrations are not within615 % of the known value, the analyst should reanalyze theCVS. If the value still falls outside acceptable limits, a newcalibration curve is required that must be confirmed by asuccessful CVS before continuing with ongoing analyses.14.2.2 One CVS should the

43、n be run with each sample batch(maximum of 20 samples) to verify the previously establishedcalibration curves. If the determined analyte concentrations falloutside acceptable limits (615 %) that analyte is judged out ofcontrol, and the source of the problem should be identifiedbefore continuing with

44、 ongoing analyses.14.3 Initial Demonstration of Laboratory Capability14.3.1 The laboratory using this test should perform aninitial demonstration of laboratory capability. Analyze seven6Supporting data are available from ASTM Headquarters. Request RR: D19-1119.FIG. 1 Precision for HydrazineTABLE 1 R

45、ecovery and BiasAmountAdded,g/LAmountFound,g/L% BiasStatisticallySignificant,%(95%ConfidenceLevel)Reagent Water Type II6.041 5.891 2.5 No51.57 51.54 0.1 No177.8 178.1 0.2 No112.9 113.2 0.3 NoSelected Water Matrices6.041 5.935 1.7 No51.57 50.77 1.6 No177.8 176.2 0.9 Yes112.9 111.2 1.5 NoD 1385 073rep

46、licates of an initial demonstration of performance (IDP)solution. The IDP solution contains method analytes of knownconcentration, prepared from a different source to the calibra-tion standards, used to fortify reagent water. Ideally, the IPDsolution should be prepared by an independent source fromr

47、eference materials. The level 2 spiking solution used for theprecision and bias study is a suitable IDP solution. The meanand standard deviation of the seven values should then becalculated and compared according to Practice D 5847.14.4 Laboratory Control Sample14.4.1 One laboratory control sample (

48、LCS) should be runwith each sample batch (maximum of 20 samples). The LCS isa solution of method analytes of known concentration added toa matrix that sufficiently challenges the test method. A syn-thetic “water” matrix of relevance to the user (for example,drinking water or wastewater) spiked with

49、the method analyteat the level of the IDP solution would be an example of anappropriate LCS. The analyte recoveries for the LCS shouldfall within the control limits of x 6 3S.14.5 A reagent blank should be run when generating theinitial calibration curves. A blank should also be run with eachsample batch (maximum of 20 samples) to check for sample orsystem contamination.14.6 Matrix Spike14.6.1 One matrix spike (MS) should be run with eachsample batch (maximum of 20 samples) to test methodrecovery. The MS should be prepared in accordance with