ASTM_D_1541_-_97.pdf

Designation:D 1541 97Standard Test Method forTotal Iodine Value of Drying Oils and Their Derivatives1This standard is issued under the fixed designation D 1541;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 method2covers the determination of totaliodine value.1.2 This test method is applicable to oils,fatty acids,andbodied oils.While this test method is applicable to all oils andfatty acids and bodied oils,it is particularly useful for thosedrying oils or derivatives that have conjugated unsaturation.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of whoever uses this standard to consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazard statements are given in Sections 6 and 7.2.Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water3D 1959 Test Method for Iodine Value of Drying Oils andFatty Acids43.Terminology3.1 Definitions:3.1.1 total iodine valuea measure of the total unsaturationpresent in fats and oils(Note 1),expressed as the number ofcentigrams of iodine equivalent to the unsaturation present in 1g of sample(weight percent of absorbed iodine).NOTE1When the total iodine value is determined on oils havingconjugated systems,the result is a measure of the total unsaturation.Thisis in contrast to the iodine value method described in Test Method D 1959which determines only part of the total unsaturation of conjugatedsystems.4.Significance and Use4.1 This test method measures the total amount of unsatura-tion including conjugated unsaturation by addition of brominein a catalyzed bromine solution to the double bonds.Theamount of bromine absorbed is determined by back titration ofthe excess bromine,and then compared to a blank determina-tion.This test method is preferred over Test Method D 1959 forproducts containing conjugated unsaturation.5.Apparatus5.1 Iodine Flasks,glass-stoppered,of 250-mL capacity.NOTE2The test may be run either in a photographic-type darkroomunder red safelight illumination5or in a darkened laboratory in which thelight intensity is adjusted to 0.5 footcandle(5.4 1x)or less.The darkroomwith red safelights permits the use of clear flasks.If the test shall be runin a darkened laboratory,low-actinic(amber)flasks,or clear flasksprotected from light by covering as described below,must be used.Alternative modes of using clear flasks in a darkened laboratory aredescribed as follows.The type of covering is left to the discretion of theanalyst:(1)Place the clear iodine flask in a suitable metal can so that the neckof the flask is level with the can rim.Over the top of the can,place a pieceof heavy cardboard,with a hole precut in the center to just fit over the neckof the flask;the top of the flask should just protrude out of the hole in thecardboard cover.Then run the analysis as usual in a darkened laboratory.(2)Wrap heavy aluminum foil around the iodine flasks so as to coverall but the top rim.The foil can be then removed at the latter stage oftitration.Run the analysis in a darkened laboratory.(3)Place the flask in an opaque bag that has a drawstring neck.The rimof the iodine flask should just protrude from the bag to allow addition ofreagent.5.2 Graduates,5,25,and 50-mL capacity.5.3 Volumetric Pipets,10,20,and 50-mL capacity.NOTE3The bulb of the 50-mL pipet should be covered with alumi-num foil.5.4 Buret,50-mL capacity graduated in 0.1-mL divisions.5.5 Weighing Device for SampleA small,wide-mouthvial,fitted with a cork stopper and medicine dropper,may beused to weigh the sample by difference.Alternatively,thesample may be weighed directly into a 1-mL microbeaker,andcarefully dropped into the iodine flask.5.6 Photoelectric Light MeterAny suitable meter for mea-suring room illumination in footcandles.If a darkroom and redsafelight illumination are to be used,a meter is not required.1This test method is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings and Materialsand is the direct responsibility of SubcommitteeD01.32on Drying Oils.Current edition approved Aug.10,1997.Published October 1997.Originallypublished as D 1541 58 T.Last previous edition D 1541 86(1995)e1.2This procedure is essentially identical with that of Planck,R.W.,Pack,F.C.,and Goldblatt,L.A.,as published in the Journal,Am.Oil Chemists Soc.,Vol 30,1953,p.417,using the Rosenmund-Kuhnhenn reagent.Previously Benham,G.H.,and Klee,L.J.,published data on the use of this reagent for determiningunsaturation in the Journal,Am.Oil Chemists Soc.,Vol 27,1950,pp.127130.3Annual Book of ASTM Standards,Vol 11.01.4Annual Book of ASTM Standards,Vol 06.03.5The sole sourc