1、Designation: D1613 17Standard Test Method forAcidity in Volatile Solvents and Chemical IntermediatesUsed in Paint, Varnish, Lacquer, and Related Products1This standard is issued under the fixed designation D1613; the number immediately following the designation indicates the year oforiginal adoption
2、 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1.
3、 Scope*1.1 This test method covers the determination of totalacidity as acetic acid, in concentrations below 0.05 %, inorganic compounds and hydrocarbon mixtures used in paint,varnish, and lacquer solvents and diluents. It is known to beapplicable to such mixtures as low molecular weight saturatedan
4、d unsaturated alcohols, ketones, ethers, esters, hydrocarbondiluents, naphtha, and other light distillate petroleum fractions.1.2 For purposes of determining conformance of an ob-served value or a calculated value using this test method torelevant specifications, test result(s) shall be rounded off
5、“tothe nearest unit” in the last right-hand digit used in expressingthe specification limit, in accordance with the rounding-offmethod of Practice E29.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 For specific hazard
6、information and guidance consultsuppliers Safety Data Sheet.1.5 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof whoever uses this standard to consult and establish appro-priate safety and health practices and determine the app
7、lica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D770 Specification for Isopropyl AlcoholD1193 Specification for Reagent WaterD4806 Specification for Denatured Fuel Ethanol for Blend-ing with Gasolines for Use as Automotive Spark-IgnitionEngine FuelD7795
8、Test Method for Acidity in Ethanol and EthanolBlends by TitrationE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE200 Practice for Preparation, Standardization, and Storageof Standard and Reagent Solutions for Chemical Analysis3. Summary of Test Meth
9、od3.1 The specimen is mixed with either an equal volume ofwater or an equal volume of alcohol, and titrated with aqueoussodium hydroxide solution to the phenolphthalein end point.4. Significance and Use4.1 This test method is useful for determining low levels ofacidity, below 0.05 %, in organic comp
10、ounds and hydrocarbonmixtures. The total acidity is calculated as acetic acid ormilligrams of sodium hydroxide per gram of sample.4.2 Acidity may be present as a result of contamination,decomposition during storage or distribution, or manufacture.This test method may be used in assessing compliance
11、with aspecification.5. Apparatus5.1 Buret, 10-mL, graduated in 0.05-mL subdivisions.5.2 Erlenmeyer Flask, 250-mL capacity.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.35
12、 on Solvents, Plasticizers, and Chemical Intermediates.Current edition approved Feb. 1, 2017. Published February 2017. Originallyapproved in 1964. Last previous edition approved in 2012 as D1613 06 (2012).DOI: 10.1520/D1613-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orc
13、ontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes
14、t Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Tr
15、ade Organization Technical Barriers to Trade (TBT) Committee.16. Purity of Reagents6.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical So
16、ciety, where suchspecifications are available.3Other grades may be used pro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.6.2 Unless otherwise indicated, references to water shall beunderstood to mean
17、 reagent water conforming to Type IV ofSpecification D1193.7. Reagents7.1 Alcohols, refined, ethyl or isopropyl.NOTE 1Isopropyl alcohol (99 % grade) conforming to SpecificationD770, or 190 proof ethyl alcohol conforming to formula No. 3A of theU.S. Bureau of Alcohol, Tobacco and Firearms is suitable
18、 for use as thesolvent. The use of methyl alcohol is not recommended.7.2 Phenolphthalein Indicator Solution (10 g/L)Dissolve1 g of phenolphthalein in ethyl or isopropyl alcohol (see Note1) and dilute to 100 mL with the alcohol.7.3 Sodium Hydroxide, Standard Solution (0.05 N)Prepare and standardize a
19、 0.05 N sodium hydroxide (NaOH)solution (Note 2) in accordance with the Preparation andStandardization of Solutions, Precision and Bias, Preparationof 50 % of NaOH Solution and of Standard Solutions, andStandardization sections of Practice E200.NOTE 2Alternatively, KOH solution may be used.8. Proced
20、ure8.1 Measure into a 250-mL Erlenmeyer flask 50 mL ofwater, if the sample is completely water-soluble, or 50 mL ofalcohol, if the sample is not completely water-soluble.8.2 Add 0.5 mL of phenolphthalein indicator solution.Titrate the water or alcohol with 0.05 N NaOH solution to thefirst perceptibl
21、e pink color.8.3 Pipet 50 mL of the sample into the flask. Titrate with the0.05 N NaOH solution to the same first perceptible pink colororiginally obtained.8.3.1 If the sample is fuel ethanol or denatured fuel ethanol,as defined in Specification D4806, purge the sample for 2 minwith 400 mL/mn of nit
22、rogen prior to pipetting (see TestMethod D7795 for additional information on purging thesample).NOTE 3It is well known that carbon dioxide is highly soluble inethanol solutions. Carbon dioxide can be dissolved into the ethanolsolution during production (especially fermentation processes), duringtran
23、sportation or during laboratory analysis. The dissolved carbon dioxideis a known interference for this test method creating incorrect elevatedacidity values. If the dissolved carbon dioxide is not removed from asample, erroneously high results can be experienced which can exceed thespecification lim
24、it. It is recommended that Test Method D7795 be used forthe determination of acidity in fuel ethanol and denatured fuel ethanol;furthermore, as is codified in Specification D4806, Test Method D7795should be considered the referee method:Section 8.4.1 from Specification D4806: “Dissolved carbon dioxi
25、de isa known interference and can cause a false high reading when using TestMethod D1613. In the absence of dissolved CO2, Test Method D1613 isan acceptable method. If a sample is known to have dissolved CO2or ifdissolved CO2can be present, Test Method D7795 is the preferredmethod. In cases of diffe
26、ring results between the two test methods, TestMethod D7795 shall be the referee method.”9. Calculations9.1 Calculate the acidity of the sample as follows:Acidity as acetic acid, weight% 5 VN 30.12!/D (1)or,Acidity as mg KOH per g of sample 5 VN 31.12!/D (2)where:V = NaOH solution required for titra
27、tion of the sample, mL,N = normality of the NaOH solution, andD = density of specimen in g/mL.10. Report10.1 Report the percent of acetic acid to the nearest0.0001 %. Duplicate runs that agree within 0.0005 %, absolute,are acceptable for averaging (95 % confidence level).11. Precision and Bias411.1
28、Precision:11.1.1 The following criteria should be used for judging theacceptability of results at the 95 % confidence level:11.1.1.1 RepeatabilityThe normal range between tworesults, each the mean of duplicate determinations, obtained bythe same analyst on different days, is estimated to be 0.0003 %
29、,absolute. Two such values should be considered suspect if theydiffer by more than 0.0008 %, absolute.11.1.1.2 ReproducibilityThe normal range between tworesults, each the mean of duplicate determinations obtained byanalysts in different laboratories, is estimated to be 0.0005 %,absolute. Two such v
30、alues should be considered suspect if theydiffer by more than 0.0014 %, absolute.NOTE 4The above precision estimates are based on an interlaboratorystudy on two samples each of n-butyl acetate, n-butyl alcohol, and methylethyl ketone containing 0.0058, 0.0112, 0.0007, 0.0046, 0.0026, and0.0067 % ace
31、tic acid, respectively. Each of four laboratories analyzed allsix samples, with two analysts in each laboratory performing duplicatedeterminations using both 99 % isopropyl alcohol and formula 3A ethanolas solvents, and repeating on a second day, for a total of 384 determina-tions.11.2 BiasThe bias
32、of this test method has not beendetermined because there is no available material with anaccepted reference value.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Soci
33、ety, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Re
34、search Report RR:D01-1041. ContactASTM CustomerService at serviceastm.org.D1613 17212. Keywords12.1 acidity; solvents; total acidity as acetic acidSUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue(D161306(2012) that may impact the u
35、se of this standard. (Approved February 1, 2017.)(1) Added D4806 Specification for Denatured Fuel Ethanol forBlending with Gasolines for Use asAutomotive Spark-IgnitionEngine Fuel as a referenced document in Section 2.(2) Added D7795 Standard Test Method for Acidity in Ethanoland Ethanol Blends by T
36、itration as a referenced document inSection 2.(3) Added new section 8.3.1 to give specific direction for usingTest Method D1613 on fuel ethanol or denatured fuel ethanol.(4) Updated Note 3 to give specific directions for the purgeconditions required when using Test Method D1613 on fuelethanol or den
37、atured fuel ethanol.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement
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