1、Designation: D3697 12D3697 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 in
2、dicates 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 dissolved and total recoverable antimony in water by atomic absorptionspectroscopy.21.2 This test method is appli
3、cable in the range from 1 to 15 g/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 reagent water, tap water, salt water, and two untreated wastewaters. Theinformation on precision and bias may not apply to o
4、ther waters.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values statedgivenin each system are mathematical conversions and may not be exact equivalents; therefore, each system shall be used independentlyof the other.parentheses are mathe
5、matical conversion to inch-pound units that are provided for information only and are notconsidered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety
6、 and health practices and determine the applicability of regulatorylimitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standard
7、s, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias of Applicable Test
8、 Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD4691 Practice for Measuring Elements in Water by Flame Atomic Absorption SpectrophotometryD4841 Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic ConstituentsD5673 Test
9、Method for Elements in Water by Inductively Coupled PlasmaMass SpectrometryD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis3. Terminology3.1 Definitions:For definitions of terms used in this test method
10、, refer to Terminology D1129.3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 continuing calibration blank, na solution containing no analytes (of interest) which is used to verify blank response
11、 andfreedom from carryover.1 This test method is under the jurisdiction ofASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.05 on Inorganic Constituents in Water.Current edition approved Sept. 1, 2012June 1, 2017. Published September 2012June 2017. Originally approved
12、in 1978. Last previous edition approved in 20072012 asD3697 07.D3697 12. DOI: 10.1520/D3697-12.10.1520/D3697-17.2 Platte, J. A., and Marcy, V. M., “A New Tool for the Water Chemist,” Industrial Water Engineering, IWEGA, May 1965.3 For referencedASTM standards, visit theASTM website, www.astm.org, or
13、 contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes hav
14、e been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official doc
15、ument.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.2 continuing calibration verification, na solution (or set of solutions) of known concentration used to verify
16、freedom fromexcessive instrumental drift; the concentration is to cover the range of calibration curve.3.2.3 laboratory control sample, na solution with a certified concentration of the antimony.3.2.4 total recoverable antimony, nan arbitrary analytical a descriptive term relating to forms of antimo
17、ny that aredeterminable by the digestion method which is included in the procedure; some organic compounds may not be completelyrecovered.3.2.2 laboratory control sample, na solution with a certified concentration of the antimony.4. Summary of Test Method4.1 Organic antimony-containing compounds are
18、 decomposed by adding sulfuric and nitric acids and repeatedly evaporating thesample to fumes of sulfur trioxide. The antimony so produced, together with inorganic antimony originally present, is subsequentlyreacted with potassium iodide and stannous chloride, and finally with sodium borohydride to
19、form stibine. The stibine is removedfrom solution by aeration and swept by a flow of nitrogen into a hydrogen flame where it is determined by atomic absorption at217.6 nm.5. Significance and Use5.1 Because of the association with lead and arsenic in industry, it is often difficult to assess the toxi
20、city of antimony and itscompounds. In humans, complaints referable to the nervous system have been reported. In assessing human cases, however, thepossibility of lead or arsenic poisoning must always be borne in mind. Locally, antimony compounds are irritating to the skin andmucous membranes.5.2 ICP
21、-MS may also be appropriate but at a higher instrument cost. See Test Method D5673.6. Interference6.1 Since the stibine is freed from the original sample matrix, interferences in the flame are minimized.6.2 Selenium and arsenic, which also form hydrides, do not interfere at concentrations of 100 g/L
22、. Higher concentrations werenot tested.7. Apparatus7.1 Atomic Absorption Spectrophotometer, for use at 217.6 nm with a scale expansion of approximately 3. A general guide forthe use of flame atomic absorption applications is given in Practice D4691.NOTE 1The manufacturers instructions should be foll
23、owed for all instrumental parameters.7.1.1 Antimony Electrodeless Discharge Lamp.7.2 Recorder or Digital ReadoutAny multirange variable speed recorder or digital readout accessory, or both, that iscompatible with the atomic absorption spectrophotometer is suitable.7.3 Stibine Vapor Analyzer, assembl
24、ed as shown in Fig. 1.NOTE 2A static system, such as one using a balloon, has been found to be satisfactory. See McFarren, E. McFarren (1979).F., “New, SimplifiedMethod for Metal Analysis,” Journal4 of American Water Works Assoc., JAWWA, Vol 64, 1972, p. 28.8. Reagents and Materials8.1 Purity of Rea
25、gentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications for the Committee on Analytical Reagents of the American Chemical Society, where4 McFarren, E. F., “New, Simplified Method for Metal Analysis,” Jou
26、rnal of American Water Works Association, JAWWA, Vol 64, 1972, p. 28.FIG. 1 Stibine Vapor AnalyzerD3697 172such specifications are available.5 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of
27、 the determination.8.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water conforming toSpecification D1193, Type I, II, or III water. Type I is preferred and more commonly used. Other reagent water types may be usedprovided it is first ascertaine
28、d that the water is of sufficiently high purity to permit its use without adversely affecting the precisionand bias of the test method. Type II water was specified at the time of round robin testing of these test methods.NOTE 3The user must ensure the type of reagent water chosen is sufficiently fre
29、e of interferences. The water should be analyzed using the test 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 with water. A purchased antimony stock solution of appropriate known purity is al
30、soacceptable.8.4 Antimony Solution, Intermediate (1.00 mL = 10 g Sb)Dilute 50.0 mLof 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 mL withwater. Prepare fresh before each use. use, or as dete
31、rmined by Practice D4841. This standard is used to prepare working standardsat the time of analysis.analysis, or as determined by Practice D4841.8.6 Hydrochloric Acid (sp gr 1.19)Concentrated hydrochloric acid (HCl).8.7 Nitric Acid (sp gr 1.42)Concentrated nitric acid (HNO3).8.8 Nitric Acid (1 + 1)A
32、dd 250 mL of concentrated nitric acid (sp gr 1.42) to 250 mL of water.8.9 Potassium Iodide Solution (15 g/100 mL)Dissolve 15 g 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)Dissolve 4 g o
33、f sodium borohydride (NaBH4) and 2 g of sodium hydroxide(NaOH) in 100 mL water. Prepare weekly.8.11 Stannous Chloride Solution (4.6 g/100 mL of concentrated HCl)Dissolve 5 g of stannous chloride (SnCl2H2O) in 100mL of concentrated HCl (sp gr 1.19). This solution is stable if a few small pieces of mo
34、ssy tin are added to prevent oxidation.8.12 Sulfuric Acid (1 + 1) (1 + 1)Cautiously, and with constant stirring and cooling, add 250 mLof concentrated sulfuric acid(H2SO4, sp gr 1.84) to 250 mL of water.8.13 Hydrogen, commercially available. Set pressure on burner control box to 55 KPa (8 psi) and a
35、djust flowmeter toapproximately 6 L/min.8.14 Nitrogen, commercially available. Set pressure on burner control box to 206.8 KPa (30 psi) and adjust flowmeter formaximum sensitivity by volatilizing standards. A flow of approximately 9 L/min has been found satisfactory. This will varydepending on the b
36、urner used.8.15 Filter PaperPurchase suitable filter paper. Typically the filter papers have a pore size of 0.45-m membrane. Materialsuch as fine-textured, acid-washed, ashless paper, or glass fiber paper are acceptable. The user must first ascertain that the filterpaper is of sufficient purity to u
37、se without adversely affecting the bias and precision of the test method.9. Sampling9.1 Collect the sample in accordance with Practices D3370. The holding time for the samples may be calculated in accordancewith Practice D4841.9.2 Immediately preserve samples with HNO3 (sp gr 1.42) to a pH of 2 or l
38、ess at the time of collection; normally about 2 mL/Lis required. If only dissolved antimony is to be determined, filter the sample through a (No. 325) 0.45-m membrane filter beforeacidification.NOTE 4Alternatively, the pH may be adjusted in the laboratory if the sample is returned within 14 days. wi
39、thin 14 days of collection. However, acidmust be added at least 24 hours before analysis to dissolve any metals that adsorb to the container walls. This could reduce hazards of working with acidsin the field when appropriate.10. Standardization10.1 Clean all glassware before use An effective way to
40、clean all glassware to be used for preparation of standard solutionsor in the digestion step, or both, is by rinsing first with HNO3 (1 + 1) (8.8) and then with water.10.2 Prepare, in 200 to 300-mL wide-mouth glass containers, a blank and sufficient standards that contain from 0.0 to 1.5 gof antimon
41、y by diluting 0.0 to 15.0-mL portions of the antimony standard solution to 100 mL with water.5 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Sta
42、ndards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D3697 17310.3 Proceed as directed in 11.3 to 11.8.10.4 Prepare Read directly in concentration if this capability is prov
43、ided with the instrument or prepare an analytical curve byplotting recorder scale readings versus micrograms of antimony on linear graph paper or calculate a standard curve. Alternatively,read directly in concentration if a concentration readout is provided with the instrument.11. Procedure11.1 Clea
44、n all glassware before use An effective way to clean all glassware to be used for preparation of standard solutions orin the digestion step, or both, is by rinsing first with HNO3 (1 + 1) (8.8)(8.8) and then with water.reagent.11.2 Pipet a volume of well-mixed acidified sample containing less than 1
45、.5 g of antimony (100-mLmax) into a 200 to 300-mLwide-mouth glass container, and dilute to 100 mL with water (see Fig. 1).NOTE 5If only dissolved antimony is to be determined, use a filtered and acidified sample (9.2).11.3 To each container, add 7 mL of H2SO4 (1 + 1) (8.12)(8.12) and 5 mL of concent
46、rated HNO3 (8.7).(8.7). Add a smallboiling chip and carefully heat the samples (between 65C to 95C) on a steam bath or hot plate below boiling in a well-ventilatedhood to evaporate to fumes of SO3. Maintain an excess of HNO3 until all organic matter is destroyed. This prevents darkening ofthe soluti
47、on and possible reduction and loss of antimony. Cool, add 25 mL of water, and again evaporate to fumes of SO3 to expeloxides to nitrogen.NOTE 6Many laboratories have found block digestion systems a useful way to digest samples for trace metals analysis. Systems typically consist ofeither a metal or
48、graphite block with wells to hold digestion tubes. The block temperature controller must be able to maintain uniformity of temperatureacross all positions of the block. The digestion block must be capable of maintaining a consistent temperature between 65C and 95C. For trace metalsanalysis, the dige
49、stion tubes should be constructed of polypropylene and have a volume accuracy of at least 0.5 %. All lots of tubes should come witha certificate of analysis to demonstrate suitability for their intended purpose.11.4 Cool, and adjust the volume of each container to approximately 100 mL with water.11.5 To each container, add successively, with thorough mixing after each addition, 8 mL of concentrated HCl (8.6),(8.6), 1 mLof KI solution (8.9),(8.9), and 0.5 mL of SnCl2 (8.11)(8.11) solution. Allow about 15 min for reaction.11.6 Attach one
