1、Designation: D5794 95 (Reapproved 2014)Standard Guide forDetermination of Anions in Cathodic Electrocoat Permeatesby Ion Chromatography1This standard is issued under the fixed designation D5794; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide is used for the determination of nitrate anionin electrocoat bath permeate by use o
3、f chemically suppressedand non-suppressed ion chromatography (IC).1.2 Other anions, with the exception of phosphate, may bedetermined in electrocoat bath permeates by use of this guide.1.3 It is the responsibility of the user of this guide toestablish appropriate safety and health practices and dete
4、rminethe applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent Water3. Significance and Use3.1 It is important to monitor the anion concentrations andanion contaminants in electrocoat baths. Wet chemical methodsare long, tedio
5、us, and of questionable accuracy in the ppmrange. Ion chromatography offers a fast, convenient andaccurate alternative. Since IC analysis of electrocoat bathsamples is difficult, the permeates are often analyzed forcontaminants. This guide addresses some important consider-ations for such analyses.4
6、. Apparatus4.1 A wide variety of ion chromatography columns, eluents,and operating parameters are available from commercialsources. The round robin studies conducted in conjunction withthis guides preparation utilized both suppressed and non-suppressed IC systems, acid and base eluents, strong and w
7、eakbase eluents, and varying gradients and flow rates. All labora-tories utilized a conductivity detector for their analysis.4.2 Any properly maintained commercial IC system capableof separating, detecting, and quantifying anions by conductiv-ity is deemed satisfactory.5. Guidelines for Analysts5.1
8、Utilize commercially available ANION standards orprepare anion standards from reagent grade chemicals andreagent water Type I (see Specification D1193).5.2 Sparge all eluent solutions with helium for at least 15min prior to performing an IC analysis.5.3 When necessary, remove residual traces of orga
9、niccompounds such as resin with properly pretreated precolumns.5.4 Utilize at least three standards for calibration. Standardsshould be in the same approximate concentration ranges as theanions concentration in the sample. Calibration standardsshould bracket the anions concentration in the sample.5.
10、5 Calibrate instrument only after chromatograms baselineis stable.5.6 Use the peak area for the specific anion of interest asdetermined by an electronic integrator.5.7 Use a sample of sufficient size to completely fill the ionchromatographs injection loop.6. Keywords6.1 cathodic electrocoat; ion chr
11、omatography; nitrate; per-meate1This guide is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved July 1, 2014. Publis
12、hed July 2014. Originally approvedin 1995. Last previous edition approved in 2008 as D5794 95 (2008) DOI:10.1520/D5794-95R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information,
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16、g of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO
17、Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 95 (2014)2
