ASTM_D_5442_-_93_2013.pdf

Designation:D544293(Reapproved 2013)Standard Test Method forAnalysis of Petroleum Waxes by Gas Chromatography1This standard is issued under the fixed designation D5442;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 This test method covers the quantitative determinationof the carbon number distribution of petroleum waxes in therange from n-C17through n-C44by gas chromatography usinginternal standardization.In addition,the content of normal andnon-normal hydrocarbons for each carbon number is alsodetermined.Material with a carbon number above n-C44isdetermined by its difference from 100 mass%and reported asC45+.1.2 This test method is applicable to petroleum derivedwaxes,including blends of waxes.This test method is notapplicable to oxygenated waxes,such as synthetic polyethyl-ene glycols(for example,Carbowax2),or natural products suchas beeswax or carnauba.1.3 This test method is not directly applicable to waxes withoil content greater than 10%as determined by Test MethodD721.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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 consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3D721 Test Method for Oil Content of Petroleum WaxesD4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD4626 Practice for Calculation of Gas ChromatographicResponse FactorsE260 Practice for Packed Column Gas ChromatographyE355 Practice for Gas Chromatography Terms and Relation-ships3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 carbon numbera number corresponding to the num-ber of carbon atoms in a hydrocarbon.3.1.2 cool on-column injectiona sample introduction tech-nique in gas chromatography where the sample is injectedinside the front portion of a partition column at a temperatureat or below the boiling point of the most volatile component inthe sample.3.1.3 low volume connectora metal or glass union de-signed to connect two lengths of capillary tubing.Usuallydesigned so that the tubing ends are joined with a minimum ofeither dead volume or overlap between them.3.1.4 non(normal paraffn)hydrocarbon(NON)all otherhydrocarbon types excluding those hydrocarbons with carbonatoms in a single length.Includes aromatics,naphthenes,andbranched hydrocarbon types.3.1.5 normal paraffna saturated hydrocarbon which hasall carbon atoms bonded in a single length,without branchingor hydrocarbon rings.3.1.6 wall coated open tube(WCOT)a term used tospecify capillary columns in which the stationary phase iscoated on the interior surface of the glass or fused silica tube.Stationary phase may be cross-linked or bonded after coating.4.Summary of Test Method4.1 Weighed quantities of the petroleum wax and an internalstandard are completely dissolved in an appropriate solvent andintroduced into a gas chromatographic column that separatesthe hydrocarbon components by increasing carbon number.The column temperature is linearly increased at a reproduciblerate until the sample is completely eluted from the column.4.2 The eluted components are detected by a flame ioniza-tion detector and recorded on a strip chart or computer system.The individual carbon numbers are identified by comparing theretention times obtained from a qualitative standard with the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0H on Chromatographic Distribution Methods.Current edition approved May 1,2013.Published August 2013.Originallyapproved in 1993.Last previous edition approved in 2008 as D5442 93(2008).DOI:10.1520/D5442-93R13.2Carbowax is a registered trademark of Union Carbide Corp.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 retention times of the wax sample.The percent of eachhydrocarbon number through C44is calculated via internalstandard calculations after applying response factors.4.3 For samples with final boiling points greater than 538Ccomplete elution of all components may not be achieved underthe specified conditions.For this reason,the C45+material isdetermined by summing the concentrations of each individualcarbon