ASTM_D_890_-_12.pdf

Designation:D89012Standard Test Method forWater in Liquid Pine Chemicals1This standard is issued under the fixed designation D890;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods cover the quantitative determinationof dissolved or occluded water present in any proportion inliquid pine chemicals,such as turpentine,pinene,dipentene,pine oil,tall oil,and tall oil fatty acids.Three methods ofmoisture testing are included.The Karl Fisher titration methodis the preferred method for testing tall oil,Test Methods D803.1.1.1 The Karl Fischer Titration method is based on thereaction between water and a complex reagent2consisting ofiodine,sulfur dioxide,pyridine,and methanol,whereby theiodine is converted to a colorless compound.The appearanceof a persistent iodine color in the reaction mixture indicates thecomplete removal of free water by reaction with the reagent,and the endpoint may be measured colorimetrically.Automatictitrators find this endpoint by the restoration of a currentstrength when the resistance provided by the presence of wateris eliminated.Amperometric automatic titrators find this end-point by detecting the current flow that occurs once water iseliminated.1.1.2 The coulometric titration method determines watercontent by electronic integration of a current sufficient togenerate the precise amount of iodine from the required reagentto react with the water in the sample.1.1.3 The azeotropic method utilizes the relatively lowboiling point of water,as compared with other sampleconstituents,in a toluene or xylene matrix so that water iscollected in a trap and measured.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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:3D803 Test Methods for Testing Tall OilD1364 Test Method for Water in Volatile Solvents(KarlFischer Reagent Titration Method)3.Significance and Use3.1 Many pine chemical products contain water as a resultof the processes used for their production.Typically refinedproducts such as terpenes,pine oil,tall oil fatty acids,anddistilled tall oil contain only traces of water,but crude tall oilmight contain 0.5 to 2.5%of water.Although the Karl Fischerand coulometric methods are most applicable to low levels ofmoisture,these can be and are used at higher levels.Theazeotropic distillation method is generally used at higherlevels.Moisture By Karl Fischer Titration(Preferred method)4.Apparatus4.1 Titration Vessel,preferably closed,with stirringcapabilities,4.2 Buret,capable of being read at 0.1 mL divisions,orautomatic buret,or4.3 Automatic Karl Fischer titrator.4.4 Balance,capable of weighing to the nearest 0.0001 g.5.Reagents5.1 Karl Fischer Reagent,or Other Suitable Reagent,suchas Pyridine-free Adaptations of Karl Fischer Reagent.Re-agents vary in strength(titer).This test method is written1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.34 on Pine Chemicals and Hydrocarbon Resins.Current edition approved Nov.1,2012.Published December 2012.Originallyapproved in 1946.Last previous edition approved in 2008 as D890-98(2008).DOI:10.1520/D0890-12.2This procedure has been adapted from the method of Karl Fischer published inZeitschrift fr Angewandte Chemie,Vol 48,1935,p.395;Chemical Abstracts,Vol29,1935 p.6532;as modified by Smith,Bryant,and Mitchell,Journal,Am.Chemical Soc.,Vol.61,1939,p.2407;and further modified by Axel Johansson,Svensk Papperstidning,Vol 50,No.11B,1947,p.124;see also Publication 19 of theSwedish Wood Research Institute,Wood Chemistry and Paper Technique(Stock-holm)(1947).Karl Fischer reagent is available from various laboratory supplies.Pyridine-free adaptations of the Karl Fischer reagent are available commercially.3For referenced ASTM standards,visit 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 assuming a titer of 5 mg water/mL reagent.Recommendedadditions of water in this test method may need to be adjusteddepending on the titer of the reagent.5.2 MethanolACS grade.6.Standardization of Iodine Reagent6.1 Add methanol to the titration vessel,and titr