1、Designation:D445815Standard Test Method forChloride Ions in Brackish Water,Seawater,and Brines1This standard is issued under the fixed designation D4458;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A numb
2、er in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method2is applicable to the measurement ofchloride in highly mineralized waters such as oil field brines,seawater,and brackish water
3、.The test method is based uponthe titration of chloride with silver nitrate,using a visualindicator.1.2 Samples containing from 10 to 150 mg of chloride canbe analyzed by this test method.These levels are achieved bydilution as described in the test method.1.3 The values stated in SI units are to be
4、 regarded asstandard.No other units of measurement are included in thisstandard.1.4 It is the users responsibility to assure the validity of themethod for untested types of water.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsib
5、ility 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.2.Referenced Documents2.1 ASTM Standards:3D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determ
6、ination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water Analysis3.Terminology3.1 De
7、finitionsFor definitions of terms used in this testmethod,refer to Terminology D1129.4.Summary of Test Method4.1 This test method is based upon the Mohr procedure fordetermining chloride ion with silver nitrate.The chloride reactswith the silver ion before any silver chromate forms,due to thelower s
8、olubility of silver chloride.The potassium chromateindicator reacts with excess silver ion to form a red silverchromate precipitate.The end point is the appearance of thefirst permanent orange color.4.2 This test method is suitable for analyzing solutions witha pH between 6.0 and 8.5.5.Significance
9、and Use5.1 Chloride is present in virtually all oil field brines,seawaters,and many waste waters.Identification of the originof the water and selection of its disposal method may be basedupon the chloride content.The chloride content is also used toestimate the resistivity of formation waters and to
10、 differentiatebetween subsurface formations.6.Interferences6.1 Sulfide,bromide,iodide,thiocyanate,cyanide,phosphate,sulfite,carbonate,hydroxide,and iron interfere inthis test method.Sulfide,sulfite,and thiosulfate can be re-moved with a peroxide treatment,but usually no attempt ismade to remove brom
11、ide and iodide because they are usuallypresent in insignificant quantities compared to chloride.Ifnecessary,the pH can be raised and the hydroxides of severalmetals,including iron,can be filtered off.Iron,barium,lead,and bismuth precipitate with the chromate indicator.7.Apparatus7.1 Laboratory Glass
12、ware.7.2 Buret,25-mL capacity.7.3 Hotplate.7.4 Magnetic Stirrer and TFE-fluorocarbon-Coated StirringBars.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of D19.05 on Inorganic Constituents in Water.Current edition approved Feb.1,2015.Publish
13、ed March 2015.Originallyapproved in 1985.Last previous edition approved in 2009 as D4458 09.DOI:10.1520/D4458-15.2Hillebrand,W.F.,Lundell,G.E.F.,Bright,H.A.,and Hoffman,J.I.,AppliedInorganic Analysis,2nd Ed.,732,John Wiley&Sons,Inc.,New York,NY,1953.3For referenced ASTM standards,visit the ASTM webs
14、ite,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 Barr Harbor Drive,
15、PO Box C700,West Conshohocken,PA 19428-2959.United States1 8.Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specification of the Committeeon Analytical Reagents of the Ameri
16、can Chemical Society,where such specifications are available.4Other 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 reagent 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 p
