ASTM_D_6632_-_01.pdf

Designation:D 6632 01Standard Test Method forTotal Copper in Antifouling Paints1This standard is issued under the fixed designation D 6632;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 indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method is for the analytical determination ofcopper in liquid samples of antifouling coatings.The procedureoutlines in detail equipment,reagents,and necessary steps tosatisfactorily determine the concentration of copper in paint.Conversion to specific copper compounds can be made byappropriate gravimetric factors.1.2 The values stated in SI units are to be regarded asstandard.The inch-pound units given in parenthesis are forinformation only.1.3 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 of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 283 Test Methods for Chemical Analysis of CuprousOxide and Copper Pigments23.Summary of Test Method3.1 Samples of the paint are weighed into beakers andsolvent is allowed to evaporate.Dry ashing is done at 600C todestroy organic materials,followed by acid digestion.Solu-tions are diluted,filtered to remove insolubles and electrolyzedto deposit the copper onto platinum gauze.Recovered copper isdetermined as percentage of sample weight and calculated tooriginal compound.4.Significance and Use4.1 This test method allows the accurate determination ofcopper content in formulated paints as a means of verifyingcomposition(see Test Methods D 283).5.Apparatus5.1 Pyrex Beakers,tall-form,400-mL with spout.5.2 Magnetic Stirrer and TFE-fluorocarbon-coated stirringbar.5.3 D.C.Power Supply to deliver approximately 3 V andapproximately 2 A.5.4 Two Electrode Holders.5.5 Platinum Gauze Electrodes,cathode and anode.5.6 Glass Filter Funnels.5.7 Hot Plate.5.8 Analytical Balance.5.9 Graduated Cylinders.6.Reagents and Materials6.1 Concentrated Nitric Acid(HNO3),reagent-grade.6.2 Perchloric Acid(HClO4),69 to 72%,reagent-grade.6.3 Deionized or Distilled Water.6.4 Alcohol or Acetone.6.5 Ammonium Sulfate.6.6 Filter Paper,Glass Fiber,approximately 1.5 m,ofsuitable diameter to fit funnel.7.Procedure7.1 Thoroughly mix the paint and place a U-shaped stirrerinto the container and while stirring,transfer and accuratelyweight approximately 1 g into each of two tared 400-mLbeakers.7.2 Allow samples to dry overnight,vaporizing solvent.7.3 Place beakers into a muffle furnace and dry ash at 600Covernight to remove acid resistant organic matter.7.4 In a laboratory hood,add 10 mL of concentrated nitricacid to each beaker to dissolve the copper-based ingredient,heating on a hot plate to dissolve sample.Boil for severalminutes with watch glass in place to reflux acid.7.5 Remove from hot plate and add 10 mL of perchloricacid,fume,and reflux on hot plate for 15 min.If insolublesremain,dilute to approximately 100 mL with water and filterthrough a glass fiber filter having approximately 1.5mparticle retention into a 400-mL tall-form beaker.If no in-solubles are present,dilute directly to approximately 200 mLand continue as in 7.7.7.6 Wash filter thoroughly to recover all soluble salts,diluting up to a volume of approximately 200 mL.7.7 Add 1 mL HNO3and 1 g of ammonium sulfate to eachcollected sample,swirl to mix.Add a magnetic stirring bar toeach beaker.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.45 on Marine Solvents.Current edition approved Feb.10,2001.Published April 2001.2Annual Book of ASTM Standards,Vol 06.03.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.7.8 Record tare weight of each clean,dry platinum gauzecylindrical cathode.7.9 Follow the power source manual,set maximum amper-age to 5.00,then adjust voltage to approximately 4 V.7.10 Attach platinum cathode unit to negative electrodeholder.Place anode in center of cathode and attach to positiveelectrode holder.7.11 Immerse electrodes into the beaker containing thefiltrate and washings,allow enough bottom clearance forstirring bar.Place magnetic stirring platform under beaker andadjust stirrer control to achieve moderate mixing.7.12 Dilute with distilled water so that approximately 6.3mm(14in.)of cathode is above solution level.Turn on powersource,adjust voltage to approximately 3 V,if necessary.7.13 Electrolyze for 2 h,copper will then deposit onplatinum gauze cathode.Add water to cover cathode andcontainer,electrolyzing for an additional 15 min.7.14 With power on,swing stirrer platform away whileholding beaker.Slowly lower beak