ASTM D3697-17 Standard Test Method for Antimony in Water.pdf

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1、Designation: D3697 17Standard Test Method forAntimony in Water1This standard is issued under the fixed designation D3697; 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 parentheses indicates

2、the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of dissolvedand total recoverable antimony in water by atomic absorptionspectroscopy.21.2 This test method is applicable in

3、the range from 1 to 15g/L of antimony. The range may be extended by less scaleexpansion or by dilution of the sample.1.3 The precision and bias data were obtained on reagentwater, tap water, salt water, and two untreated wastewaters.The information on precision and bias may not apply to otherwaters.

4、1.4 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversion to inch-pound units that are provided for informa-tion only and are not considered standard.1.5 This standard does not purport to address all of thesafety concerns, if any, ass

5、ociated 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.1.6 This international standard was developed in accor-dance with internationally recognized princi

6、ples on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3D1129 Terminology Relating to Wat

7、erD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD4691 Practice for Measuring Elements in Water by FlameAtomic Absorption SpectrophotometryD4841 Prac

8、tice for Estimation of Holding Time for WaterSamples Containing Organic and Inorganic ConstituentsD5673 Test Method for Elements in Water by InductivelyCoupled PlasmaMass SpectrometryD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specificationsfor Standard Tes

9、t Methods for Water Analysis3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer toTerminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 continuing calibration blank, na solution contain-ing no analytes (of interest) which is used to verify b

10、lankresponse and freedom from carryover.3.2.2 continuing calibration verification, na solution (orset of solutions) of known concentration used to verify freedomfrom excessive instrumental drift; the concentration is to coverthe range of calibration curve.3.2.3 laboratory control sample, na solution

11、 with a certi-fied concentration of the antimony.3.2.4 total recoverable antimony, na descriptive termrelating to forms of antimony that are determinable by thedigestion method which is included in the procedure; someorganic compounds may not be completely recovered.4. Summary of Test Method4.1 Orga

12、nic antimony-containing compounds are decom-posed by adding sulfuric and nitric acids and repeatedlyevaporating the sample to fumes of sulfur trioxide. Theantimony so produced, together with inorganic antimonyoriginally present, is subsequently reacted with potassiumiodide and stannous chloride, and

13、 finally with sodium borohy-dride to form stibine. The stibine is removed from solution byaeration and swept by a flow of nitrogen into a hydrogen flamewhere it is determined by atomic absorption at 217.6 nm.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct

14、responsibility of Subcommittee D19.05 on Inorganic Constituentsin Water.Current edition approved June 1, 2017. Published June 2017. Originallyapproved in 1978. Last previous edition approved in 2012 as D3697 12. DOI:10.1520/D3697-17.2Platte, J. A., and Marcy, V. M., “A New Tool for the Water Chemist

15、,” IndustrialWater Engineering, IWEGA, May 1965.3For 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.*A Summary of

16、 Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in th

17、e Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15. Significance and Use5.1 Because of the association with lead and arsenic inindustry, it is often difficult to asse

18、ss the toxicity of antimonyand its compounds. In humans, complaints referable to thenervous system have been reported. In assessing human cases,however, the possibility of lead or arsenic poisoning mustalways be borne in mind. Locally, antimony compounds areirritating to the skin and mucous membrane

19、s.5.2 ICP-MS may also be appropriate but at a higher instru-ment cost. See Test Method D5673.6. Interference6.1 Since the stibine is freed from the original samplematrix, interferences in the flame are minimized.6.2 Selenium and arsenic, which also form hydrides, do notinterfere at concentrations of

20、 100 g/L. Higher concentrationswere not tested.7. Apparatus7.1 Atomic Absorption Spectrophotometer, for use at 217.6nm with a scale expansion of approximately 3. A general guidefor the use of flame atomic absorption applications is given inPractice D4691.NOTE 1The manufacturers instructions should b

21、e followed for allinstrumental parameters.7.1.1 Antimony Electrodeless Discharge Lamp.7.2 Recorder or Digital ReadoutAny multirange variablespeed recorder or digital readout accessory, or both, that iscompatible with the atomic absorption spectrophotometer issuitable.7.3 Stibine Vapor Analyzer, asse

22、mbled as shown in Fig. 1.NOTE 2A static system, such as one using a balloon, has been foundto be satisfactory. See McFarren (1979).48. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conf

23、orm to the specifications for the Com-mittee on Analytical Reagents of the American ChemicalSociety, where such specifications are available.5Other gradesmay be used, provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe accuracy of th

24、e determination.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D1193, Type I, II, or III water. Type I ispreferred and more commonly used. Other reagent water typesmay be used provided it is first ascertained tha

25、t the water is ofsufficiently high purity to permit its use without adverselyaffecting the precision and bias of the test method. Type IIwater was specified at the time of round robin testing of thesetest methods.NOTE 3The user must ensure the type of reagent water chosen issufficiently free of inte

26、rferences. The water should be analyzed using thetest method.8.3 Antimony Solution, Stock (1.00 mL = 100 g Sb)Dissolve 274.3 mg of antimony potassium tartrate,KSbOC4H4O61/2H2O, in water and dilute to 1000 mL withwater. A purchased antimony stock solution of appropriateknown purity is also acceptable

27、.8.4 Antimony Solution, Intermediate (1.00 mL = 10 gSb)Dilute 50.0 mL of antimony stock solution to 500.0 mLwith water.8.5 Antimony Solution, Standard (1.0 mL = 0.10 g Sb)Dilute 5.0 mL of antimony intermediate solution to 500.0 mLwith water. Prepare fresh before each use, or as determined byPractice

28、 D4841. This standard is used to prepare workingstandards at the time of analysis, or as determined by PracticeD4841.8.6 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).8.7 Nitric Acid (sp gr 1.42)Concentrated nitric acid(HNO3).8.8 Nitric Acid (1+1)Add 250 mL of concentrated nitr

29、icacid (sp gr 1.42) to 250 mL of water.8.9 Potassium Iodide Solution (15 g/100 mL)Dissolve 15g of potassium iodide (KI) in 100 mL of water. This solution isstable when stored in an amber bottle or in the dark.8.10 Sodium Borohydride Solution (4 g/100 mL)Dissolve4 g of sodium borohydride (NaBH4)and2g

30、ofsodiumhydroxide (NaOH) in 100 mL water. Prepare weekly.8.11 Stannous Chloride Solution (4.6 g/100 mL of concen-trated HCl)Dissolve5gofstannous chloride (SnCl2H2O) in100 mL of concentrated HCl (sp gr 1.19). This solution isstable if a few small pieces of mossy tin are added to preventoxidation.4McF

31、arren, E. F., “New, Simplified Method for Metal Analysis,” Journal ofAmerican Water Works Association, JAWWA, Vol 64, 1972, p. 28.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the Americ

32、an Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Stibine Vapor AnalyzerD3697 1728.12 Sulfuric Acid (1 + 1)Cautiously, and with co

33、nstantstirring and cooling, add 250 mL of concentrated sulfuric acid(H2SO4, sp gr 1.84) to 250 mL of water.8.13 Hydrogen, commercially available. Set pressure onburner control box to 55 KPa (8 psi) and adjust flowmeter toapproximately 6 L/min.8.14 Nitrogen, commercially available. Set pressure onbur

34、ner control box to 206.8 KPa (30 psi) and adjust flowmeterfor maximum sensitivity by volatilizing standards. A flow ofapproximately 9 L/min has been found satisfactory. This willvary depending on the burner used.8.15 Filter PaperPurchase suitable filter paper. Typicallythe filter papers have a pore

35、size of 0.45-m membrane.Material such as fine-textured, acid-washed, ashless paper, orglass fiber paper are acceptable. The user must first ascertainthat the filter paper is of sufficient purity to use withoutadversely affecting the bias and precision of the test method.9. Sampling9.1 Collect the sa

36、mple in accordance with Practices D3370.The holding time for the samples may be calculated inaccordance with Practice D4841.9.2 Immediately preserve samples with HNO3(sp gr 1.42)to a pH of 2 or less at the time of collection; normally about 2mL/L is required. If only dissolved antimony is to bedeter

37、mined, filter the sample through a (No. 325) 0.45-mmembrane filter before acidification.NOTE 4Alternatively, the pH may be adjusted in the laboratory within14 days of collection. However, acid must be added at least 24 hoursbefore analysis to dissolve any metals that adsorb to the container walls.Th

38、is could reduce hazards of working with acids in the field whenappropriate.10. Standardization10.1 An effective way to clean all glassware to be used forpreparation of standard solutions or in the digestion step, orboth, is by rinsing first with HNO3(1 + 1) (8.8) and then withwater.10.2 Prepare, in

39、200 to 300-mL wide-mouth glasscontainers, a blank and sufficient standards that contain from0.0 to 1.5 g of antimony by diluting 0.0 to 15.0-mL portionsof the antimony standard solution to 100 mL with water.10.3 Proceed as directed in 11.3 to 11.8.10.4 Read directly in concentration if this capabili

40、ty isprovided with the instrument or prepare an analytical curve byplotting recorder scale readings versus micrograms of anti-mony on linear graph paper or calculate a standard curve.11. Procedure11.1 An effective way to clean all glassware to be used forpreparation of standard solutions or in the d

41、igestion step, orboth, is by rinsing first with HNO3(1+1)(8.8) and then withreagent.11.2 Pipet a volume of well-mixed acidified sample contain-ing less than 1.5 g of antimony (100-mL max) into a 200 to300-mL wide-mouth glass container, and dilute to 100 mL withwater (see Fig. 1).NOTE 5If only dissol

42、ved antimony is to be determined, use a filteredand acidified sample (9.2).11.3 To each container, add 7 mL of H2SO4(1+1)(8.12)and 5 mLof concentrated HNO3(8.7).Add a small boiling chipand carefully heat the samples (between 65C to 95C) on asteam bath or hot plate below boiling in a well-ventilated

43、hoodto evaporate to fumes of SO3. Maintain an excess of HNO3until all organic matter is destroyed. This prevents darkening ofthe solution and possible reduction and loss of antimony. Cool,add 25 mL of water, and again evaporate to fumes of SO3toexpel oxides to nitrogen.NOTE 6Many laboratories have f

44、ound block digestion systems auseful way to digest samples for trace metals analysis. Systems typicallyconsist of either a metal or graphite block with wells to hold digestiontubes. The block temperature controller must be able to maintain unifor-mity of temperature across all positions of the block

45、. The digestion blockmust be capable of maintaining a consistent temperature between 65Cand 95C. For trace metals analysis, the digestion tubes should beconstructed of polypropylene and have a volume accuracy of at least 0.5%. All lots of tubes should come with a certificate of analysis todemonstrat

46、e suitability for their intended purpose.11.4 Cool, and adjust the volume of each container toapproximately 100 mL with water.11.5 To each container, add successively, with thoroughmixing after each addition, 8 mL of concentrated HCl (8.6), 1mL of KI solution (8.9), and 0.5 mL of SnCl2(8.11) solutio

47、n.Allow about 15 min for reaction.11.6 Attach one container at a time to the rubber stoppercontaining the gas dispersion tube.11.7 Fill the medicine dropper or syringe with 1 mL ofNaBH4(8.10) solution and insert into the hole in the rubberstopper.11.8 Add the NaBH4solution (8.10) to the sample solut

48、ion.After the recorder reading (scale reading) has reached amaximum and has returned to the baseline, remove thecontainer. Rinse the gas dispersion tube in water beforeproceeding to the next sample. Treat each succeeding sample,blank, and standard in a like manner.12. Calculation12.1 If instrument r

49、eadout is not in concentration, determinethe weight or concentration of antimony in each sample byreferring to 10.4. If the weight is determined from theanalytical curve, calculate the concentration of antimony in thesample in micrograms per litre, as follows:Antimony, g/L 5 1000 3W/V (1)where:1000 = 1000 mL / L,V = volume of sample, mL, andW = weight of antimony in sample, g.13. Precision and Bias13.1 The single operator and overall precision of this testmethod for four laboratories, which included a total of sixoperators analyzi