ASTM D1691-2002(2007)e1 Standard Test Methods for Zinc in Water《水中锌含量的标准试验方法》.pdf

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1、Designation: D 1691 02 (Reapproved 2007)e1Standard Test Methods forZinc in Water1This standard is issued under the fixed designation D 1691; 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 par

2、entheses 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.e1NOTEPractice D 2777 98 was editorially changed throughout to D 2777 06 in Au

3、gust 2007.1. Scope1.1 These test methods cover the determination of zinc inwater. Two test methods are given as follows:Test Method ConcentrationRangeSectionsAAtomic Absorption, Direct 0.05 to 2 mg/L 8-16BAtomic Absorption,Chelation-Extraction20 to 200 g/L 17-251.2 Either dissolved or total recovera

4、ble zinc may be deter-mined.1.3 These test methods have been used successfully withreagent grade water. See the specific test method for applica-bility to other matrices. It is the users responsibility to assurethe validity of these test methods in other matrices.1.4 This standard does not purport t

5、o address all of thesafety concerns, if any, associated with its use. It is theresponsibility 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. For specific hazardstatements, see Section 6 and N

6、ote 5, Note 8, and Note 13.1.5 Two former colorimetric test methods were discontin-ued. Refer to Appendix X1 for historical information.2. Referenced Documents2.1 ASTM Standards:2D 858 Test Methods for Manganese in WaterD 1066 Practice for Sampling SteamD 1068 Test Methods for Iron in WaterD 1129 Te

7、rminology Relating to WaterD 1192 Guide for Equipment for Sampling Water andSteam in Closed Conduits3D 1193 Specification for Reagent WaterD 1687 Test Methods for Chromium in WaterD 1688 Test Methods for Copper in WaterD 1886 Test Methods for Nickel in WaterD 2777 Practice for Determination of Preci

8、sion and Bias ofApplicable Test Methods of Committee D19 on WaterD 3370 Practices for Sampling Water from Closed ConduitsD 3557 Test Methods for Cadmium in WaterD 3558 Test Methods for Cobalt in WaterD 3559 Test Methods for Lead in WaterD 4841 Practice for Estimation of Holding Time for WaterSamples

9、 Containing Organic and Inorganic ConstituentsD 5810 Guide for Spiking into Aqueous SamplesD 5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water Analysis3. Terminology3.1 Definitions: For definitions of terms used in these testmethods, refer to Terminology D 1

10、129.3.2 Definitions of Terms Specific to This Standard:3.2.1 total recoverable zincan arbitrary analytical termrelating to the recoverable form of zinc that is determinable bythe digestion method which is included in the Procedure.4. Significance and Use4.1 Zinc is an essential and beneficial elemen

11、t in bodygrowth. Concentrations above 5 mg/L can cause a bitterastringent taste and opalescence in alkaline waters. The zincconcentration of U.S. drinking waters varies between 0.06 and7.0 mg/L with a mean of 1.33 mg/L. Zinc most commonlyenters the domestic water supply from deterioration of galva-n

12、ized iron and dezincification of brass. Zinc in water also mayresult from industrial water pollution.45. Purity of Reagents5.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the Committee on Analyt

13、ical1These test methods are under the jurisdiction of ASTM Committee D19 onWater and are the direct responsibility of Subcommittee D19.05 on InorganicConstituents in Water.Current edition approved Aug. 1, 2007. Published August 2007. Originallyapproved in 1959. Last previous edition approved in 2002

14、 as D 1691 02.2For 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.3Withdrawn.4“Standard Methods for the Examinati

15、on of Water and Wastewater,” 16thedition, 1985, APHA, AWWA-WPCF.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Reagents of the American Chemical Society, where suchspecifications are available.5Other grades may be used, pro-vided it

16、 is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.5.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D 1193, Type I. Other reage

17、nt water types maybe used, provided it is first ascertained that the water is ofsufficiently high purity to permit its use without adverselyaffecting the bias and precision of the test method. Type IIwater was specified at the time of round-robin testing of thistest method.6. Hazards6.1 Although zin

18、c is nontoxic to man, these test methodsrequire the use of certain other toxic and hazardous reagentsand materials. Each should be used with care and exertingproper precautions.7. Sampling7.1 Collect the sample in accordance with Practice D 1066,Specification D 1192, and Practices D 3370, as applica

19、ble.7.2 Samples shall be preserved with nitric acid (HNO3) (spgr 1.42) to a pH of 2 or less immediately at the time ofcollection, normally about 2 mL/L of HNO3. If only dissolvedzinc is to be determined, the sample, shall be filtered througha 0.45-m membrane filter before acidification. The holdingt

20、ime for samples may be calculated in accordance with PracticeD 4841.TEST METHOD AATOMIC ABSORPTION, DIRECT8. Scope8.1 This test method covers the determination of dissolvedand total recoverable zinc in most waters and wastewaters.8.2 This test method is applicable in the range from 0.05 to2.0 mg/L o

21、f zinc. The range may be extended to concentrationsgreater than 2.0 mg/L by dilution of the sample.8.3 This test method has been used successfully withreagent grade water, river water, wastewater, ground water, tapwater, lake water, refinery effluent. The information on preci-sion and bias may not a

22、pply to other waters.9. Summary of Test Method9.1 Zinc is determined by atomic absorption spectropho-tometry. Dissolved zinc is determined by aspirating a portionof the filtered and preserved sample directly with no pretreat-ment. Total recoverable zinc is determined by aspirating thesample followin

23、g hydrochloric-nitric acid digestion and filtra-tion. The same digestion procedure is used to determine totalrecoverable cadmium (Test Methods D 3557), chromium, (TestMethods D 1687), cobalt (Test Methods D 3558), copper (TestMethods D 1688), iron (Test Methods D 1068), lead (TestMethods D 3559), ma

24、nganese (Test Methods D 858), andnickel (Test Methods D 1886).10. Interferences10.1 Sodium, potassium, sulfate, and chloride (9000 mg/Leach), calcium and magnesium (4000 mg/Leach), nitrate (2000mg/L), and cadmium, lead, copper, nickel, cobalt, and chro-mium (10 mg/L each) do not interfere.10.2 Backg

25、round correction or a chelation-extraction proce-dure (see Test Method B) may be necessary to determine lowlevels of zinc in some waters.NOTE 1Instrument manufacturers instructions for use of the specificcorrection technique should be followed.11. Apparatus11.1 Atomic Absorption Spectrophotometer, f

26、or use at 213.9nm.NOTE 2The manufacturers instructions should be followed for allinstrumental parameters. Wavelengths other than 213.9 nm may be used ifthey have been determined to be equally suitable.11.1.1 Zinc Light SourceHollow-cathode lamps or elec-trodeless discharge lamps have been found sati

27、sfactory.11.2 OxidantSee 12.6.11.3 FuelSee 12.7.11.4 Pressure-Reducing ValvesThe supplies of fuel andoxidant shall be maintained at pressures somewhat higher thanthe controlled operating pressure of the instrument by suitablevalves.12. Reagents and Materials12.1 Hydrochloric Acid (sp gr 1.19)Concent

28、rated hydro-chloric acid (HCl).NOTE 3If the reagent blank concentration is greater than the methoddetection limit, distill the HCl or use a spectrograde acid. WarningWhen HCl is distilled an azeotropic mixture is obtained (approximately 6N HCl). Therefore, whenever concentrated HCl is specified in t

29、hepreparation of a reagent or in the procedure, use double the amountspecified if a distilled acid is used.12.2 Nitric Acid (sp gr 1.42)Concentrated nitric acid(HNO3).NOTE 4If the reagent blank concentration is greater than the methoddetection limit, distill the HNO3or use a trace metal grade acid.1

30、2.3 Nitric Acid (1 +499)Add 1 volume of HNO3(sp gr1.42) to 499 volumes of water.12.4 Zinc Solution, Stock (1 mL = 1.0 mg Zn)Dissolve1.245 g of zinc oxide (ZnO) in a mixture of 10 mL of HNO3(spgr 1.42) and 10 mL of water. Dilute to 1 L with water. Apurchased stock solution of appropriate purity is al

31、so accept-able.12.5 Zinc Solution, Standard (1 mL = 0.1 mg Zn)Dilute100.0 mL of the zinc stock solution and 1 mL of HNO3(sp gr1.42) to 1 L with water.12.6 Oxidant:12.6.1 Air, which has been passed through a suitable filter toremove oil, water, and other foreign substances, is the usualoxidant.5Reage

32、nt 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 Pharmacopeiaand

33、National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D 1691 02 (2007)e1212.7 Fuel:12.7.1 AcetyleneStandard, commercially available acety-lene is the usual fuel. Acetone, always present in acetylenecylinders, can affect analytical results. The cylinder should bereplaced at 50

34、psig (345 kPa).NOTE 5Warning: “Purified” grade acetylene containing a specialproprietary solvent rather than acetone should not be used with poly(vinylchloride) tubing as weakening of the tubing walls can cause a potentiallyhazardous situation.13. Standardization13.1 Prepare 100 mL each of a blank a

35、nd at least fourstandard solutions to bracket the expected zinc concentrationrange of the samples to be analyzed by diluting the standardzinc solution (12.5) with HNO3(1 +499). Prepare the standardseach time the test is to be performed and select so as to givezero, middle, and maximum points for an

36、analytical curve.13.2 When determining total recoverable zinc, add 0.5 mLof HNO3(sp gr 1.42) to each blank and standard solution andproceed as directed in 14.2-14.4. After the digestion of theblank and standard solutions has been completed in 14.4, returnto 13.3 to complete the standardization for t

37、otal recoverabledeterminations. To determine dissolved zinc, proceed with13.3.13.3 Aspirate the blank and standards, and record theabsorbance of each at 213.9 nm. Aspirate HNO3(1 +499)between each standard.13.4 Prepare an analytical curve by plotting the absorbanceversus concentration for each stand

38、ard. Alternatively, readdirectly in concentration from the instrument.14. Procedure14.1 Measure 100.0 mL of a well-mixed acidified sampleinto a 125-mL beaker or flask.NOTE 6If only dissolved zinc is to be determined, start with 14.5.14.2 Add 5 mL of HCl (sp gr 1.19) to each sample.14.3 Heat the samp

39、les on a steam bath or hotplate in awell-ventilated hood until the volume has been reduced to 15to 20 mL, making certain that the samples do not boil.NOTE 7For samples with appreciable amounts of suspended matter ordissolved solids, the amount of reduction in the volume is left to thediscretion of t

40、he analyst.14.4 Cool and filter the samples through a suitable filter,such as fine-textured, acid-washed, ashless paper, into 100-mLvolumetric flasks. Wash the filter paper two or three times withwater and adjust to volume.14.5 Aspirate each filtered and acidified sample and stan-dard and determine

41、its absorbance or concentration at 213.9nm. Atomize HNO3(1 +499) between each sample and stan-dard.15. Calculation15.1 Calculate the concentration of zinc in each sample, inmilligrams per litre, using the analytical curve prepared in 13.4or read directly in concentration.16. Precision and Bias616.1

42、The overall precision and bias of this test method,within its designated range, is shown in Table 1.16.2 These collaborative test data were obtained fromeleven laboratories on reagent grade, river, lake, ground andeffluent waters. For other waters these data may not apply.16.3 Precision and bias for

43、 this test method conform toPractice D 2777 77, which was in place at the time ofcollaborative testing. Under the allowances made in 1.4 ofPractice D 2777 06, these precision and bias data do meetexisting requirements for interlaboratory studies of CommitteeD19 test methods.TEST METHOD BATOMIC ABSOR

44、PTION,CHELATIONEXTRACTION17. Scope17.1 This test method covers the determination of dissolvedand total recoverable zinc in most waters and brines.17.2 This test method is applicable in the range from 20 to200 g/L of zinc.17.3 This test method has been used successfully withreagent grade water, river

45、 water, wastewater, ground water, tapwater, lake water, refinery effluent. The information on preci-sion and bias may not apply to other waters.18. Summary of Test Method18.1 Zinc is determined by atomic absorption spectropho-tometry. The element, either dissolved or total recoverable, ischelated wi

46、th pyrrolidine dithiocarbamic acid and extractedwith chloroform. The extract is evaporated to dryness, treatedwith hot nitric acid to destroy organic matter, dissolved inhydrochloric acid, and diluted to a specified volume with water.The resulting solution is then aspirated into the air-acetylenefla

47、me of the spectrophotometer. The digestion procedure sum-marized in 9.1 is used when determining total recoverable zinc.The same chelation-extraction procedure is used to determinetotal recoverable cadmium (Test Methods D 3557), cobalt (TestMethods D 3558), copper (Test Methods D 1688), iron (TestMe

48、thods D 1068), lead (Test Methods D 3559), and nickel(Test Methods D 1886).6Supporting data are available fromASTM International Headquarters, 100 BarrHarbor Dr., West Conshohocken, PA 19428-2959. Request RR: D19-1039.TABLE 1 Determination of Precision and Bias for Zinc by AtomicAbsorption, DirectAm

49、ountAdded,mg/LAmountFound,mg/LST,mg/LSO,mg/L%,BiasStatisticallySignificant,95 % LevelReagent Water0.16 0.172 0.052 0.038 + 7.5 No0.80 0.798 0.068 0.034 0.2 No1.50 1.459 0.107 0.041 2.7 YesWater of Choice0.16 0.172 0.041 0.033 + 7.5 Yes0.80 0.796 0.081 0.047 0.5 No1.50 1.446 0.098 0.060 3.6 YesD 1691 02 (2007)e1319. Interferences19.1 See Section 10.20. Apparatus20.1 Apparatus described in Section 11 are required.21. Reagents and Materials21.1 Bromphenol Blue Indicator Solution (1 g/L)Dissolve 0.1 g of bromphenol blue in 100 mL of 50 % eth