1、Designation: D1688 07D1688 12Standard Test Methods forCopper in Water1This standard is issued under the fixed designation D1688; 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 ind
2、icates the year of last reapproval. Asuperscript epsilon () 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. Scope Scope*1.1 These test methods cover the determination of copper in water by atomic
3、absorption spectrophotometry. Three test methodsare included as follows:Test Method ConcentrationRange SectionsAAtomic Absorption,Direct0.05 to 5 mg/L 7-15BAtomic Absorption,Chelation-Extraction50 to 500 g/L 16-24CAtomic Absorption,Graphite Furnace5 to 100 g/L 25-331.2 Either dissolved or total reco
4、verable copper may be determined. Determination of dissolved copper requires filtrationthrough a 0.45-m (No. 325) membrane filter at the time of collection. In-line membrane filtration is preferable.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as the sta
5、ndard. The values givenstatedin parentheses are provided for information only.each system are mathematical conversions and may not be exact equivalents;therefore, each system shall be used independently of the other.1.4 This standard does not purport to address all of the safety concerns, if any, as
6、sociated 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. For specific hazard statements, see Note 34, Note 56, Note 810, and Note 1316.1.5 Three former photo
7、metric test methods were discontinued. Refer to Appendix X1 for historical information.2. Referenced Documents2.1 ASTM Standards:2D858 Test Methods for Manganese in WaterD1066 Practice for Sampling SteamD1068 Test Methods for Iron in WaterD1129 Terminology Relating to WaterD1192 Guide for Equipment
8、for Sampling Water and Steam in Closed Conduits (Withdrawn 2003)3D1193 Specification for Reagent WaterD1687 Test Methods for Chromium in WaterD1691 Test Methods for Zinc in WaterD1886 Test Methods for Nickel in WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods of
9、 Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3557 Test Methods for Cadmium in WaterD3558 Test Methods for Cobalt in WaterD3559 Test Methods for Lead in WaterD3919 Practice for Measuring Trace Elements in Water by Graphite Furnace Atomic Absorption Spectrophotometry1
10、 These test methods are under the jurisdiction of ASTM Committee D19 on Water and are the direct responsibility of Subcommittee D19.05 on Inorganic Constituentsin Water.Current edition approved Aug. 1, 2007Sept. 1, 2012. Published August 2007 September 2012. Originally approved in 1959. Last previou
11、s edition approved in 20022007as D1688 02.D1688 07. DOI: 10.1520/D1688-07.10.1520/D1688-12.2 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 Sum
12、mary 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 have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommend
13、s 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 document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, W
14、est Conshohocken, PA 19428-2959. United States1D4841 Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic ConstituentsD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analys
15、is3. Terminology3.1 Definitions: For definitions of terms used in these test methods, refer to Terminology D1129.4. Significance and Use4.1 Copper is found in naturally occurring minerals principally as a sulfide, oxide, or carbonate. It makes up approximately0.01 % of the earths crust and is obtain
16、ed commercially from such ores as chalcopyrite (CuFeS2). Copper is also found inbiological complexes such as hemocyanin.4.2 Copper enters water supplies through the natural process of dissolution of minerals, through industrial effluents, through itsuse, as copper sulfate, to control biological grow
17、th in some reservoirs and distribution systems, and through corrosion of copperalloy water pipes. Industries whose wastewaters may contain significant concentrations of copper include mining, ammunitionproduction, and most metal plating and finishing operations. It may occur in simple ionic form or
18、in one of many complexes withsuch groups as cyanide, chloride, ammonia, or organic ligands.4.3 Although its salts, particularly copper sulfate, inhibit biological growth such as some algae and bacteria, copper isconsidered essential to human nutrition and is not considered a toxic chemical at concen
19、trations normally found in water supplies.5. Purity of Reagents5.1 Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conformto the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such
20、specifications areavailable. 3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its usewithout lessening the accuracy of the determination.5.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mea
21、n reagent water conforming toSpecification D1193, Type I. Other reagent water types may be used, provided it is first ascertained that the water is of sufficientlyhigh purity to permit its use without lessening the bias and precision of the determination. Type II water was specified at the timeof ro
22、und-robin testing of this test method.6. Sampling6.1 Collect the sample in accordance with Practices D1066, Specification D1192, and Practices D3370, as applicable.6.2 Samples shall be preserved with nitric acid (HNO3, sp gr 1.42) to a pH of 2 or less immediately at the time of collection,normally a
23、bout 2 mL/L. If only dissolved copper is to be determined, the sample shall be filtered through a 0.45-m (No. 325)membrane filter before acidification. The holding time for samples may be calculated in accordance with Practice D4841.NOTE 1Alternatively, the pH may be adjusted in the laboratory if th
24、e sample is returned within 14 days. This could reduce hazards of working withacids in the field when appropriate.TEST METHOD AATOMIC ABSORPTION, DIRECT7. Scope7.1 This test method covers the determination of dissolved and total recoverable copper in most waters and waste waters.7.2 This test method
25、 is applicable in the range from 0.05 to 5 mg/L of copper. The range may be extended to concentrationsgreater than 5 mg/L by dilution of the sample.7.3 Collaborative test data were obtained on reagent water, river water, tap water, ground water, lake water, refinery primarytreated effluent, and two
26、untreated waste waters. The information on precision and bias may not apply to other waters.8. Summary of Test Method8.1 Copper is determined by atomic absorption spectrophotometry. Dissolved copper in the filtered sample is aspirated directlywith no pretreatment.Total recoverable copper in the samp
27、le is aspirated following hydrochloric-nitric acid digestion and filtration.The same digestion procedure may be used to determine total recoverable cadmium (Test Methods D3557), chromium (TestMethods D1687), cobalt (Test Methods D3558), iron (Test Methods D1068), lead (Test Methods D3559), manganese
28、 (TestMethods D858), nickel (Test Methods D1886), and zinc (Test Methods D1691).3 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 Standards for La
29、boratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D1688 1229. Interferences9.1 Sodium, potassium, sulfate, and chloride (8000 mg/Leach), calcium and magnesium (5000 mg/Leach), nitrate
30、 (2000 mg/L),iron (1000 mg/L), and cadmium, lead, nickel, zinc, cobalt, manganese, and chromium (10 mg/L each) do not interfere.9.2 Background correction or a chelation-extraction procedure (see Test Method B) may be necessary to determine low levelsof copper in some waters.NOTE 2Instrument manufact
31、urers instructions for use of the specific correction technique should be followed.10. Apparatus10.1 Atomic Absorption Spectrophotometer , for use at 324.7 nm.NOTE 3The manufacturers instructions should be followed for all instrumental parameters. A wavelength other than 324.7 nm may be used if it h
32、asbeen determined to be equally suitable.10.1.1 Copper Hollow-Cathode LampMultielement hollow-cathode lamps are available and have been found satisfactory.10.2 OxidantSee 11.8.10.3 FuelSee 11.9.10.4 Pressure-Reducing ValvesThe supplies of fuel and oxidant shall be maintained at pressures somewhat hi
33、gher than thecontrolled operating pressure of the instrument by suitable valves.11. Reagents and Materials11.1 Copper Solution, Stock (1.0 mL = 1.0 mg Cu)Dissolve 1.000 g of electrolytic copper contained in a 250-mL beaker ina mixture of 15 mLof HNO3 (sp gr 1.42) and 15 mLof water. Slowly add 4 mLof
34、 H2SO4 (1 + 1) and heat until SO3 fumes evolve.Cool, wash down the beaker with water, and dilute to 1 L with water. A purchased copper stock solution of adequate appropriateknown purity is also acceptable.11.2 Copper Solution, Standard (1.0 mL = 0.1 mg Cu)Dilute 100.0 mL of copper stock solution to
35、1 L with water.11.3 Hydrochloric Acid (sp gr 1.19)Concentrated hydrochloric acid (HCl).NOTE 4If a high reagent blank is obtained, distill the HCl or use a spectrograde acid. CautionWhen HCl is distilled an azeotropic mixture isobtained (approximately 6 N HCl). Therefore, whenever concentrated HCl is
36、 specified for the preparation of a reagent or in the procedure, use doublethe volume specified if distilled HCl is used.11.4 Nitric Acid (sp gr 1.42)Concentrated nitric acid (HNO3).NOTE 5If a high reagent blank is obtained, distill the HNO3 or use a spectrograde acid.11.5 Nitric Acid (1 + 499)Add 1
37、 volume of HNO3 (sp gr 1.42) to 499 volumes of water.11.6 Sulfuric AcidConcentrated sulfuric acid (H2SO4).11.7 Sulfuric Acid (1 + 1)Cautiously, and with constant stirring and cooling, add 1 volume of concentrated sulfuric acid(H2SO4, sp gr 1.84) to 1 volume of water.11.8 Oxidant:11.8.1 Air, which ha
38、s been passed through a suitable filter to remove oil, water, and other foreign substances, is the usualoxidant.11.9 Fuel:11.9.1 AcetyleneStandard, commercially available acetylene is the usual fuel.Acetone, always present in acetylene cylinders,can affect analytical results. The cylinder should be
39、replaced at 50 psig (345 kPa).345 kPa (50 psi).NOTE 6Precaution: “Purified” grade acetylene containing a special proprietary solvent rather than acetone should not be used with poly(vinylchloride) tubing as weakening of the tubing walls can cause a potentially hazardous situation.12. Standardization
40、12.1 Prepare 100 mL each of a blank and at least four standard solutions to bracket the expected copper concentration rangeof the samples to be analyzed by diluting the standard copper solution (11.2) with HNO3 (1 + 499). (1 + 499 (11.5). Prepare thestandards each time the test is to be performed.12
41、.2 When determining total recoverable copper add 0.5 mL of HNO3 (sp gr 1.42) and(11.4)and proceed as directed in13.2-13.4. When determining dissolved copper proceed with 13.5.12.3 Aspirate the blank and standards and record the instrument readings. Aspirate HNO3 (1 + 499) (11.5) between eachstandard
42、.12.4 Prepare an analytical curve by plotting the absorbance versus standard concentration for each standard.Alternatively, readdirectly in concentration from the instrument.D1688 12313. Procedure13.1 Measure 100.0 mL of a well-mixed acidified sample into a 125-mL beaker or flask.NOTE 7If only disso
43、lved copper is to be determined, start with 13.5.13.2 Add 5 mL of HCl (sp gr 1.19) (11.3) to each sample.13.3 Heat the samples on a steam bath or hotplate in a well-ventilated hood until the volume has been reduced to 15 to 20 mL,making certain that the samples do not boil.NOTE 8When analyzing sampl
44、es containing appreciable amounts of suspended matter, the amount of reduction in volume is left to the discretion ofthe analyst.NOTE 9Many laboratories have found block digestion systems a useful way to digest samples for trace metals analysis. Systems typically consist ofeither a metal or graphite
45、 block 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
46、of tubes should come with a certificate of analysis to demonstrate suitability for their intended purpose.13.4 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 with water a
47、nd adjust to volume.13.5 Aspirate each filtered and acidified sample and determine its absorbance or concentration at 324.7 nm. Aspirate HNO3(1 + 499) (11.5) between each sample.14. Calculation14.1 Calculate the concentration of copper in each sample, in milligrams per L, using an analytical curve o
48、r alternatively, readdirectly in concentration (see 12.4).15. Precision and Bias415.1 The collaborative test of this test method was performed by ten laboratories, five of which supplied two operators each.Each of the 15 operators made determinations at three levels on three different days in sample
49、s of reagent water and water of choicefor a total of 270 determinations.15.2 These collaborative test data were obtained on reagent grade water, river water, tap water, ground water, lake water,refinery primary treated effluent, and two untreated waste waters. For other matrices, these data may not apply.15.3 Precision and bias for this test method conform to Practice D2777-77, which was in place at the time of collaborativetesting. Under the allowances made in 1.4 of Practice D2777-06,-08, these precision and bias data do meet existing requir
