1、Designation: D3697 07D3697 12Standard 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 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
3、 applicable 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 appl
4、y to other waters.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem are mathematical conversions and may not be exact equivalents; therefore, each system shall be used independently of theother.1.5 This standard do
5、es 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 and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Stand
6、ards:3D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD4691 Practice for Measuring Elements in Water by Flame Atom
7、ic Absorption SpectrophotometryD4841 Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic ConstituentsD5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis3. Terminology3.1 Definitions:For definitions of terms use
8、d in this test method, refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 total recoverable antimonyantimony, nan arbitrary analytical term relating to forms of antimony that are determinableby the digestion method which is included in the procedure. Someprocedure; s
9、ome 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 decomposed by adding sulfuric and nitric acids and repeatedly evaporatingthe sample
10、to fumes of sulfur trioxide. The antimony so produced, together with inorganic antimony originally present, is1 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
11、 Aug. 1, 2007Sept. 1, 2012. Published August 2007September 2012. Originally approved in 1978. Last previous edition approved in 20022007as D3697 02.D3697 07. DOI: 10.1520/D3697-07.10.1520/D3697-12.2 Platte, J. A., and Marcy, V. M., “A New Tool for the Water Chemist,” Industrial Water Engineering, IW
12、EGA, May 1965.3 For referencedASTM standards, visit theASTM website, www.astm.org, or 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 in
13、tended only to provide the user of an ASTM standard an indication of what changes have 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 cur
14、rent versionof the standard as published by ASTM is to be considered the official document.*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 States1subsequently reacted with pota
15、ssium iodide and stannous chloride, and finally with sodium borohydride to form stibine.The stibineis removed from solution by aeration and swept by a flow of nitrogen into a hydrogen flame where it is determined by atomicabsorption at 217.6 nm.5. Significance and Use5.1 Because of the association w
16、ith lead and arsenic in industry, it is often difficult to assess the toxicity 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,
17、 antimony compounds are irritating to the skin andmucous membranes.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. Higher concent
18、rations 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 followed for all in
19、strumental parameters.7.1.1 Antimony Electrodeless Discharge Lamp.7.2 Recorder or Digital Readout Any multirange variable speed recorder or digital readout accessory, or both, that iscompatible with the atomic absorption spectrophotometer is suitable.7.3 Stibine Vapor Analyzer, assembled as shown in
20、 Fig. 1.NOTE 2A static system, such as one using a balloon, has been found to be satisfactory. See McFarren, E. F., “New, Simplified Method for MetalAnalysis,” Journal of American Water Works Assoc., JAWWA, Vol 64, 1972, p. 28.8. Reagents and Materials8.1 Purity of Reagents Reagent grade chemicals s
21、hall 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, wheresuch specifications are available.4 Other grades may be used, provided it is first ascertained th
22、at the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of the determination.8.2 Purity of Water Unless otherwise indicated, references to water shall be understood to mean reagent water conformingto Specification D1193, Type I, II, or III water. Type I is prefe
23、rred and more commonly used. Other reagent water types may beused provided it is first ascertained that the water is of sufficiently high purity to permit its use without adversely affecting theprecision and bias of the test method. Type II water was specified at the time of round robin testing of t
24、hese test methods.NOTE 3The user must ensure the type of reagent water chosen is sufficiently free 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 dil
25、ute to 1000 mL with water. A purchased antimony stock solution of adequate appropriate known purity isalso acceptable.8.4 Antimony Solution, Intermediate (1.00 mL = 10 g Sb)Dilute 50.0 mLof antimony stock solution to 500.0 mLwith water.4 Reagent Chemicals, American Chemical Society Specifications, A
26、merican Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc.
27、 (USPC), Rockville, MD.FIG. 1 Stibine Vapor AnalyzerD3697 1228.5 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. This standard is used to prepare working standards at the time of analysis.8.6 Hydroc
28、hloric 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)Add 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
29、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 of 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 concentrate
30、d 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 mossy tin are added to prevent oxidation.8.12 Sulfuric Acid (1 + 1) Cautiously, and with constant stirring and cooling, add 250 mLof concentrated sulfuric ac
31、id (H2SO4,sp gr 1.84) to 250 mL of water.8.13 Hydrogen, commercially available. Set pressure on burner control box to 8 psig (55 KPa)55 KPa (8 psi) and adjustflowmeter to approximately 6 L/min.8.14 Nitrogen, commercially available. Set pressure on burner control box to 30 psig (206.8 KPa)206.8 KPa (
32、30 psi) and adjustflowmeter for maximum sensitivity by volatilizing standards. A flow of approximately 9 L/min has been found satisfactory. Thiswill vary depending on the burner used.9. Sampling9.1 Collect the sample in accordance with Practices D3370. The holding time for the samples may be calcula
33、ted in accordancewith 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 2 mL/Lis required. If only dissolved antimony is to be determined, filter the sample through a (No. 325) 0.45-m membrane filter beforeacidificat
34、ion.NOTE 4Alternatively, the pH may be adjusted in the laboratory if the sample is returned within 14 days. This could reduce hazards of working withacids in the field when appropriate.10. Standardization10.1 Clean all glassware before use by rinsing first with HNO3 (1 + 1) (8.8) and then with water
35、.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 antimony by diluting 0.0 to 15.0-mL portions of the antimony standard solution to 100 mL with water.10.3 Proceed as directed in 11.3 to 11.8.10.4 Prepare an analytical curve
36、 by plotting recorder scale readings versus micrograms of antimony on linear graph paper orcalculate a standard curve. Alternatively, read directly in concentration if a concentration readout is provided with the instrument.11. Procedure11.1 Clean all glassware before use by rinsing first with HNO3
37、(1 + 1) (8.8) and then with water.11.2 Pipet a volume of well-mixed acidified sample containing less than 1.5 g of antimony (100-mL max) into a 200 to300-mL wide-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 a
38、nd acidified sample (9.2).11.3 To each container, add 7 mL of H2SO4 (1 + 1) (8.12) and 5 mL of concentrated HNO3. (8.7). Add a small boiling chipand carefully evaporate to fumes of SO3. Maintain an excess of HNO3 until all organic matter is destroyed.This prevents darkeningof the solution and possib
39、le reduction and loss of antimony. Cool, add 25 mL of water, and again evaporate to fumes of SO3 toexpel oxides 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 graphite bloc
40、k with wells to hold digestion tubes. The block temperature controller must be able to maintain uniformity of temperatureacross all positions of the block. For trace metals analysis, the digestion tubes should be constructed of polypropylene and have a volume accuracy ofat least 0.5%. All lots of tu
41、bes should come with a 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, HCl
42、 (8.6), 1mL of KI solution, solution (8.9), and 0.5 mL of SnCl2 (8.11) solution. Allow about 15 min for reaction.D3697 12311.6 Attach one container at a time to the rubber stopper containing the gas dispersion tube.11.7 Fill the medicine dropper or syringe with 1 mL of NaBH4 (8.10) solution and inse
43、rt into the hole in the rubber stopper.11.8 Add the NaBH4 solution (8.10) to the sample solution. After the recorder reading (scale reading) has reached a maximumand has returned to the baseline, remove the container. Rinse the gas dispersion tube in water before proceeding to the next sample.Treat
44、each succeeding sample, blank, and standard in a like manner.12. Calculation12.1 Determine the weight or concentration of antimony in each sample by referring to 10.4. If the weight is determined fromthe analytical curve, calculate the concentration of antimony in the sample in micrograms per litre,
45、 as follows:Antimony,g/L510003W/Vwhere:1000 = 1000 mL / LiterV = volume of sample, mL, andW = weight of antimony in sample, g.13. Precision and Bias13.1 The single operator and overall precision of this test method for four laboratories, which included a total of six operatorsanalyzing each sample o
46、n three different days, within its designated range varies with the quantity being tested.13.2 Recoveries of known amounts of antimony (from antimony potassium tartrate) in a series of prepared standard for thesame laboratories and operators are given in Table 1.13.3 The precision and bias data were
47、 obtained on reagent water, tap water, salt water, and two untreated wastewaters. Theinformation on precision and bias may not apply to other waters.13.4 Precision and bias for this test method conforms to Practice D2777-77, which was in place at the time of collaborativetesting. Under the allowance
48、s made in 1.4 of D2777-06,-08, these precision and bias data do meet existing requirements forinterlaboratory studies of Committee D19 test methods.14. Quality Control (QC)14.1 The following quality control information is recommended for the determination of antimony in water.14.2 The instrument sha
49、ll be calibrated using a minimum of four calibration standards and a calibration blank. The calibrationcorrelation coefficient shall be equal to or greater than 0.990. In addition to the initial calibration blank, a calibration blank shouldbe analyzed at the end of the batch run to ensure contamination was not a problem during the batch analysis.14.3 An instrument check standard shall be analyzed at a minimum frequency of 10 % throughout the batch analysis. The valueof the instrument check standard shall fall between 80 % and 120 % of the tru
