ASTM D1246-2016 Standard Test Method for Bromide Ion in Water《测量水中溴离子的标准试验方法》.pdf

《ASTM D1246-2016 Standard Test Method for Bromide Ion in Water《测量水中溴离子的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM D1246-2016 Standard Test Method for Bromide Ion in Water《测量水中溴离子的标准试验方法》.pdf（5页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: D1246 16Standard Test Method forBromide Ion in Water1This standard is issued under the fixed designation D1246; 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 indicat

2、es 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 U.S. Department of Defense.1. Scope*1.1 This test method is applicable to the measurement ofbromide ion in water, gro

3、und water, and drinking water.1.2 Samples containing 0.5 mg/L to 1000 mg/L of bromidemay be analyzed by this test method. The concentration rangemay be extended by the dilution of an appropriate aliquot.1.3 The precision and bias statements were determined onnatural and ground waters. It is the resp

4、onsibility of the analystto assure the validity of this test method for untested matrices.1.4 A titrimetric and two colorimetric test methods foriodide and bromide were discontinued. Refer to Appendix X1for historical information.1.5 The values stated in SI units are to be regarded asstandard. No ot

5、her units of measurement are included in thisstandard.1.6 This standard does not purport to 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

6、of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1066 Practice for Sampling SteamD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 P

7、ractices for Sampling Water from Closed ConduitsD4127 Terminology Used with Ion-Selective ElectrodesD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water Analysis3. Terminology3.1 Definitions:3.1.1 For definitions of

8、terms used in this standard, refer toTerminologies D1129 and D4127.4. Summary of Test Method4.1 Bromide ion is measured potentiometrically using abromide ion-selective electrode in conjunction with a single-junction, sleeve-type reference electrode. Potentials are read ona pH meter having an expande

9、d millivolt scale capable of beingread to the nearest 0.1 mV, or a selective ion meter having adirect concentration scale for bromide. For less precise work, apH meter having a millivolt scale capable of being read to thenearest 1.0 mV is adequate, however, no supporting data areavailable.4.2 The el

10、ectrodes are calibrated in known bromide solu-tions and the concentrations of unknowns are determined insolutions with the same background. In most cases, addition ofan ionic strength adjustor to both standards and samples issufficient to maintain constant background ionic strength. Forsamples above

11、 0.1 M in ionic strength, prepare standardsolutions similar to the sample composition.5. Significance and Use5.1 By analysis for bromide in water, wastewater, andbrackish waters, it is possible to evaluate the origin of thewater, its potential as a source of bromide, and its conditionwith regard to

12、pollution.6. Interferences6.1 Strongly reducing solutions and solutions containingions which form insoluble silver salts may coat the electrodemembrane. These may be removed by polishing the membranesurface. Sulfide ion and cyanide ion both poison the electrode,and should be removed (see Section 11)

13、.6.2 Halide ions form complexes with some metals. Sincethe electrode responds only to free bromide ions, the presenceof any complexing agents lowers the measured concentrations.Concentrations of free metal ions causing a 10 % error of a1This test method is under the jurisdiction of ASTM Committee D1

14、9 on Waterand is the direct responsibility of Subcommittee D19.05 on Inorganic Constituentsin Water.Current edition approved June 15, 2016. Published June 2016. Originallyapproved in 1952. Last previous edition approved in 2010 as D1246 10. DOI:10.1520/D1246-16.2For referenced ASTM standards, visit

15、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 Changes section appears at the end of this standardCopyright ASTM International, 100

16、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1bromide concentration of 8.1 mg/L are bismuth+3, 80 mg/L;cadmium+2, 100 mg/L; lead+2, 1600 mg/L; tin+2, 2400 mg/L;and thallium+3, 4 mg/L.6.3 Chloride ion and hydroxide ion do not interfere whenpresent in the concentratio

17、ns of up to 400 and 30 000 times thebromide concentration, respectively. There will be no interfer-ence from ammonia when present in concentrations twice thatof bromide, nor from thiosulfate 20 times as concentrated asbromide. Iodide is an interference at a concentration ratio aslow as 2 104. Mercur

18、y should be absent from samples.7. Apparatus7.1 pH Meter, capable of reading to 0.1 mV, or a selective-ion meter.7.2 Bromide Ion-Selective Electrode.7.3 Sleeve-Type Single-Junction Reference Electrode, filledwith manufacturers filling solution.7.4 Mixer, magnetic, with a TFE fluorocarbon-coated stir

19、-ring bar.7.5 Laboratory Glassware.8. Reagents8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such

20、specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, referenceto water shall be understood to mean rea

21、gent water conformingto Specification D1193, Type I. Other reagent 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 r

22、ound robin testing of thistest method.8.3 Ionic Strength Adjustor (42.5 g/100 mL NaNO3)In a100-mL volumetric flask, dissolve 42.5 g of sodium nitrate(NaNO3) in water and dilute to volume.8.4 Nickel Sulfate Solution, 1 MIn a 100 mL volumetricflask dissolve 26.3 g of nickel sulfate hexahydrate (NiSO46

23、H2O) in water and dilute to volume.8.5 Sodium Bromide Standard Solution, 1000 mg/LIna1L volumetric flask dissolve 1.288 g dried sodium bromide inwater and dilute to volume. Alternatively, certified bromidestock solutions of appropriate known purity are commerciallyavailable through chemical supply v

24、endors and may be used.8.6 Sodium Bromide Standard Solutions, (100, 10, and 1mg/L)Dilute 1 volume of the 1000 mg/L bromide standardwith 9 volumes of water to prepare the 100 mg/L standard. Byfurther 1+9 serial dilutions, prepare the 10 and 1 mg/Lstandards.9. Sampling9.1 Collect the samples in accord

25、ance with Practice D1066and Practices D3370, as applicable.10. Calibration and Standardization10.1 To 100 mL of the 1, 10, 100, and 1000 mg/L NaBrstandards add 2 mL of the ionic strength adjustor (ISA). If anysamples require treatment for interferences, prepare standardswith the same background.10.2

26、 Connect and fill electrodes in accordance with manu-facturers instructions.10.3 Transfer the 1 mg/L standard-ISAmixture to a 150 mLbeaker and stir gently using the magnetic mixer. Immerse theelectrodes in the solution and wait 2 min for the potential tostabilize. Record the value.10.4 Rinse electro

27、des thoroughly and repeat for the 10, 100,and 1000 mg/L standard-ISA mixtures. Wait 2 min and recordthe potential.10.5 Follow manufacturer instructions for calibratingselective-ion meters with a direct reading of concentrationcapabilities. For pH meters, generate a calibration curve bycreating a cal

28、ibration curve on semilogrithmic graph paper orby creating a plot of mV potential versus log(10) concentra-tion. Note that volume corrections are incorporated into thecalibration, so that samples analyzed according to Section 11 ofthis test method can be read directly.11. Procedure11.1 To any sample

29、 containing sulfide or cyanide ion, add0.1 mL nickel sulfate solution to 100 mL sample.NOTE 1This concentration of nickel sulfate will react with 58 mg/Lsulfide and 117 mg/L cyanide.11.2 Transfer 100 mL sample to a 150 mL beaker and add 2mL ionic strength adjustor. Stir thoroughly for 1 min using th

30、emagnetic mixer.11.3 Immerse the electrodes in the sample-ISA mixture andwait 2 min for the potential to stabilize. Record the value.11.4 Read bromide concentration of the sample, in mg/L,directly from the meter. Note that volume corrections areincorporated into the calibration.12. Precision and Bia

31、s412.1 PrecisionThe overall and single-operator precisionof this test method may be expressed as follows:3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see

32、Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research R

33、eport RR:D19-1078. ContactASTM CustomerService at serviceastm.org.D1246 16212.1.1 For Reagent Water:ST5 0.077X11.10, coefficient of correlation 5 1.0SO5 0.067X10.79, coefficient of correlation 5 1.012.1.2 For Water Matrices:ST5 0.064X10.84, coefficient of correlation 5 1.0SO5 0.049X10.09, coefficien

34、t of correlation 5 1.0where:ST= overall precision, mg/L,SO= single-operator precision, mg/L, andX = concentration of bromide determined.12.2 The selected water matrices included natural waters,ground waters, and tap water. These data on precision and biasmay not apply to waters of other matrices.12.

35、3 BiasRecoveries of known amounts of bromide fromreagent water and selected water matrices were as shown inTable 1.12.4 This information is derived from round-robin testing,in which five laboratories, including eight operators, partici-pated. Of the eight sets of data ranked, as described in Practic

36、eD2777, none was rejected. One operator submitted reagentwater data only. One outlier data point within each set was alsorejected. Four sample levels were run on three days and blankswere obtained for the water used.12.5 This section on precision and bias conforms to PracticeD2777 77, which was in p

37、lace at the time of collaborativetesting. Under the allowances made in 1.4 of PracticeD2777 13, these precision and bias data do meet existingrequirements for interlaboratory studies of Committee D19 testmethods.13. Quality Control13.1 In order to be certain that analytical values obtainedusing thes

38、e test methods are valid and accurate within theconfidence limits of the test, the following QC procedures mustbe followed when analyzing bromide.13.2 Calibration and Calibration Verification:13.2.1 Analyze at least three working standards containingconcentrations of bromide that bracket the expecte

39、d sampleconcentration prior to analysis of samples to calibrate theinstrument.13.2.2 Verify instrument calibration after standardization byanalyzing a standard at the concentration of one of thecalibration standards. Alternately, the concentration of a mid-range standard should fall within 6 15 % of

40、 the knownconcentration.13.2.3 If calibration cannot be verified, recalibrate theinstrument.13.3 Initial Demonstration of Laboratory Capability:13.3.1 If a laboratory has not performed the test before, or ifthere has been a major change in the measurement system, forexample, new analyst, new instrum

41、ent, and so forth, a precisionand bias study must be performed to demonstrate laboratorycapability.13.3.2 Analyze seven replicates of a standard solutionprepared from an Independent Reference Material containing amid-range concentration of bromide. The matrix and chemistryof the solution should be e

42、quivalent to the solution used in thecollaborative study. Each replicate must be taken through thecomplete analytical test method including any sample preser-vation and pretreatment steps.13.3.3 Calculate the mean and standard deviation of theseven values and compare to the acceptable ranges of bias

43、 inTable 1. This study should be repeated until the recoveries arewithin the limits given in Table 1. If a concentration other thanthe recommended concentration is used, refer to PracticeD5847 for information on applying the F test and t test inevaluating the acceptability of the mean and standard d

44、evia-tion.13.4 Laboratory Control Sample (LCS):13.4.1 To ensure that the test method is in control, prepareand analyze a LCS containing a mid-range concentration ofbromide with each batch (laboratory-defined or 20 samples).The laboratory control samples for a large batch should coverthe analytical r

45、ange when possible. It is recommended, but notrequired to use a second source, if possible and practical for theLCS. The LCS must be taken through all of the steps of theanalytical method including sample preservation and pretreat-ment. The result obtained for the LCS shall fall within 615 %of the k

46、nown concentration.13.4.2 If the result is not within these limits, analysis ofsamples is halted until the problem is corrected, and either allthe samples in the batch must be reanalyzed, or the results mustbe qualified with an indication that they do not fall within theperformance criteria of the t

47、est method.13.5 Method Blank:13.5.1 Analyze a reagent water test blank with eachlaboratory-defined batch. The concentration of bromide foundin the blank should be less than 0.5 times the lowest calibrationstandard. If the concentration of bromide is found above thislevel, analysis of samples is halt

48、ed until the contamination iseliminated, and a blank shows no contamination at or abovethis level, or the results must be qualified with an indicationthat they do not fall within the performance criteria of the testmethod.13.6 Matrix Spike (MS):13.6.1 To check for interferences in the specific matri

49、xbeing tested, perform a MS on at least one sample from eachTABLE 1 Recoveries of Known Amounts of Bromide fromReagent Water and Selected Water MatricesAmountadded,mg/LAmountfound,mg/LBias,%StatisticallySignificant(95 % Con-fidenceLevel)Reagent 0.65 0.77 + 18.5 yesWater 1.00 1.19 + 19.0 no92.7 96.4 + 3.99 no864 854 1.16 noWater 0.65 0.80 + 23.1 yes1.00 1.21 + 21.5 yes92.7 95.6 + 3.2 no864 836 3.3 yesD1246 163laboratory-defined batch by spiking an aliquot of the samplewith a known concentration of bromide and taking it throughthe analytical method.13.6.2 Th