1、Designation: D848 14Standard Test Method forAcid Wash Color of Industrial Aromatic Hydrocarbons1This standard is issued under the fixed designation D848; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、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. Scope*1.1 This test method covers the determination of the
3、 acidwash color of benzene, toluene, xylenes, refined solventnaphthas, and similar industrial aromatic hydrocarbons.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 thesafe
4、ty 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. For specific hazardstatements, see Sections 8 and 12.1.2. Referenced Docum
5、ents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD3437 Practice for Sampling and Handling Liquid CyclicProductsD4790 Terminology of Aromatic Hydrocarbons and RelatedChemicalsD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terials2.
6、2 Other Document:3OSHA Regulations, 29 CFR paragraphs 1910.1000 and1910.12003. Terminology3.1 See Terminology D4790 for definitions of terms used inthis test method.4. Summary of Test Method4.1 Amixture of the aromatic hydrocarbon and sulfuric acidis vigorously shaken and the color of the acid layer
7、 is comparedwith that of color standards prepared from CoCl2and FeCl3.5. Significance and Use5.1 This test method is suitable for setting specifications onthe materials referenced in 1.1. It may also be used as aninternal quality control tool and in development or researchwork.5.2 The color develope
8、d in the acid layer gives an indicationof impurities which if sulfonated would cause the material tobe discolored.6. Apparatus6.1 Containers for Color StandardsClear andunblemished, clean, French square, flint-glass, flat-bottom,glass-stoppered, 30-mL capacity bottles holding 31 to 33 mLwhen filled
9、to the neck.4The bottles shall be labeled with thereference number of the color standard they contain (see 11.2).6.2 Test ContainersContainers exactly like those de-scribed in 6.1 except that each French square bottle shall bemarked by etching to show when the bottle contains thevolume of 7 and 28 m
10、L, respectively. Colored crayons andsimilar markers shall not be used for marking the bottles.7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analy
11、tical Reagents of the American Chemical Society,1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.01 on Benzene, Toluene, Xylenes, Cyclohexane and TheirDerivatives.Current edition approv
12、ed Feb. 1, 2014. Published February 2014. Originallyapproved in 1945. Last previous edition approved in 2009 as D848 09. DOI:10.1520/D0848-14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vol
13、ume information, refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.4The sole source of supply of the apparatus known to the
14、 committee at this timeis Ramin USA Corporation, 39019 FM 149 Rd., Magnolia, TX 77354. If you areaware of alternative suppliers, please provide this information to ASTM Interna-tional Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee,1w
15、hich you may attend.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1where such specifications are available.5Other grades may beused provided it is first ascertained tha
16、t the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean distilled water, Type I orII as described in Specification D1193.7.3 Cobalt Chloride (CoCl26H
17、2O).7.4 Ferric Chloride (FeCl36H2O).7.5 Hydrochloric Acid (1 + 39)Mix 25 mL of hydrochlo-ric acid (31 weight % HCl) with 975 mL of water.7.6 Potassium Chromate (K2CrO4).7.7 Potassium Dichromate (K2Cr2O7).7.8 Sulfuric Acid (96 6 0.5 weight % H2SO4).7.9 Sulfuric Acid (78 6 0.5 weight % H2SO4).8. Hazar
18、ds8.1 Consult current OSHA regulations, suppliers MaterialSafety Data Sheets, and local regulations for all materials usedin this test method.8.2 When handling strong acids or acid cleaning solutions,wear proper personnel protective equipment.9. Sampling9.1 Sample the material in accordance with Pra
19、ctice D3437.10. Cleaning of Containers10.1 Clean new containers (Section 6) with a cleaningsolution that will not impact the results, such as a chromic acidsubstitute, rinse with tap water followed by distilled water, anddry in an oven set at a minimum of 105C for at least 1 h.Likewise, clean all ot
20、her glassware used in this test method.11. Preparation of Reference Color StandardsNOTE 1Purchase of solutions or reference color standards, or both, isallowed. The user of this standard assumes the responsibility of ensuringany purchased solutions or standards are prepared with materials that meett
21、he requirements expressed in the Reagents section of this standard.Likewise, the user of this standard assumes the responsibility of ensuringany purchased solutions or standards are prepared as expressed in thissection.11.1 Stock SolutionsPrepare the following basic reagentsolutions for use in prepa
22、ring the reference color standards:11.1.1 Solution ADissolve 59.50 g of CoCl26H2O in HCl(1 + 39) and make up to 1 L in a volumetric flask with HCl(1 + 39).11.1.2 Solution BDissolve 45.054 g of FeCl36H2O in HCl(1 + 39) and make up to 1 L in a volumetric flask with HCl(1 + 39).11.1.3 Solution CMix 312
23、 volumes of Solution A with3612 volumes of Solution B and dilute with 90 volumes ofwater.11.1.4 Solution DMix 312 volumes of Solution A with3612 volumes of Solution B.11.1.5 Solution EPrepare an aqueous solution of K2CrO4saturated at 21C.11.1.6 Solution FPrepare an aqueous solution of K2Cr2O7saturat
24、ed at 21C and dilute with an equal volume of water.11.2 Prepare reference color standard solutions having thefollowing compositions and numbered as specified below. It isnot required to make each color standard. Only those referencecolor standards that bracket the samples being evaluated mustbe util
25、ized.No. 0Distilled water.No. 11 volume of Solution C plus 1 volume of water.No. 2512 volumes of Solution C plus 2 volumes of water.No. 3Solution C.No. 41 volume of Solution D plus 1 volume of water.No. 5512 volumes of Solution D plus 2 volumes of water.No. 6Solution D.No. 75 volumes of Solution E p
26、lus 2 volumes of water.No. 8Solution E.No. 97 volumes of Solution E plus12 volume of Solution F.No. 10612 volumes of Solution E plus 1 volume of Solution F.No. 11512 volumes of Solution E plus 2 volumes of Solution F.No. 121 volume of Solution E plus 1 volume of Solution F.No. 132 volumes of Solutio
27、n E plus 5 volumes of Solution F.No. 14Solution F.11.3 Rinse the No. 0 container (6.1) and its glass stopperthree times with water, fill with water, and stopper. Rinse theNo. 1 container and its stopper three times with reference colorstandard solution No. 1 (11.2), fill with this solution, andstopp
28、er. In this way, prepare the set of containers of colorstandards from 0 through 14 having the compositions shownfor the corresponding color solution standards in 11.2. Whenfilling the French square bottles, leave 6 mm of vapor spacebelow the neck of the bottle. Seal each container with paraffinto pr
29、event loss by evaporation or seepage.NOTE 2It is recommended color standards be prepared annually fromfresh solutions.12. Procedure12.1 Fill a clean, dry test container to the 7-mL mark withthe acid of the strength specified in Table 1 for the type of5Reagent Chemicals, American Chemical Society Spe
30、cifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Conv
31、ention, Inc. (USPC), Rockville,MD.TABLE 1 Acid Strengths and Standing TimesSampleSulfuricAcidStrength,%StandingTime,minGroup 1 Benzene, all ASTM gradesToluene, all ASTM gradesXylene, nitration gradeXylene, 5Xylene, 10Any other more highly refinedproducts96 15Group 2 Xylene, industrial gradeRefined s
32、olvent naphtha96 5Group 3 Hi-flash solventHeavy solvent naphtha78 5D848 142sample to be tested . Add sufficient sample to bring the totalvolume to the 28-mL mark (Note 3). Insert the stopper, hold afinger over the stopper, and give vigorous shakes with a strokeof 13 to 25 cm, shaking for a total of
33、150 cycles over a periodof 40 to 50 s, that is at a rate of 3 to 3.75 cycles/s. (Use of anautomatic shaker is allowed given it can be shown to producecomparable results to the manual technique.) (WarningConcentrated sulfuric acid will cause severe burns on contactwith the skin. As a precaution the t
34、est container should bewrapped in a towel or enclosed in a plastic bag during theshaking period. The test should be performed using appropriatepersonal protective equipment.)NOTE 3If the room temperature is above 29C, maintain the acid,sample, and reference color standards at a temperature between 2
35、5 and29C through the test, and insulate the test container in some convenientway, such as wrapping with a cloth, during the shaking period.12.2 Allow the container to stand, protected from directsunlight, for the period of time shown in Table 1. Withoutfurther delay, invert the container gently once
36、 or twice toobtain a uniform color in the acid layer, and compare the colorof the acid layer with that of the standards (11.3). Make thecomparison against a white background or against daylight,using transmitted light (Note 4). When testing samples inGroup 1 (Table 1), observe the color of the oil l
37、ayer as well asthat of the acid layer. Standards used shall include standardsone number above and one number below the sample, exceptfor the samples reading 0 or 14.NOTE 4Agreement of results may be improved by using a colorcomparator of a suitable type for observing the color of the acid layer inco
38、mparison with the reference standard color solution.12.3 Designate the color of the acid layer by the number ofthe nearest matching standard, following the number with aplus or minus sign if the sample is darker or lighter,respectively, than the standard. Disregard any difference in hueand determine
39、 only whether the color of the acid layer is darkeror lighter than the color of the reference standard to which thesample most nearly corresponds. If the hue of the acid color isdifferent from the hue of the reference color standard, recordthe color number followed by (X). Thus “No. 4 (X)” meansthat
40、 the acid wash test color is slightly lighter than No. 4 colorstandard and that the hue of the No. 4 color standard is not thesame as the hue of the acid layer.12.4 Dispose of the acid and hydrocarbon properly beforecleaning the container. Clean the test container by flushingthoroughly with water (t
41、ap grade or better) until traces of acidhave been removed. The test container must be completely drybefore being placed back into use.NOTE 5Suitable solvents, that will not impact the results, may be usedafter the water rinse step to assist in drying the container.13. Interpretation of Results13.1 R
42、eport Group 1 samples (Table 1) as passing the testonly when the oil layer shows no change in color and when theacid layer is not darker than the specified color standard. Acloudiness or haze in the oil layer should not be interpreted asa change in color.13.2 When testing samples of Groups 2 or 3, d
43、isregard thecolor of the oil layer and report the sample as passing the testwhen the acid layer is not darker than the specified colorstandard.14. Precision and Bias14.1 Precision data have not been established for all types ofsamples on which this test method is used. Limited cooperativetests were
44、conducted in 1961, principally to establish equalitywith the previously used shaking procedure. Precision esti-mates taken from these data are as follows:Repeatability ReproducibilityAverage AcidWash ColorDegreesofFreedom95 %Repeat-abilityDegreesofFreedom95 %Repro-ducibilityBenzene 1.46.111120.751.8
45、59102.344.47Xylene 4.710.212120.401.1410101.393.5215. Quality Guidelines15.1 Laboratories shall have a quality control system inplace.15.1.1 Confirm the performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of standard statistical quality cont
46、rol practices.15.1.2 A quality control sample is a stable material isolatedfrom the production process and representative of the samplebeing analyzed.15.1.3 When QA/QC protocols are already established inthe testing facility, these protocols are acceptable when theyconfirm the validity of test resul
47、ts.15.1.4 When there are no QA/QC protocols established inthe testing facility, use the guidelines described in GuideD6809 or similar statistical quality control practices.16. Keywords16.1 acid wash color; aromatic hydrocarbonsD848 143SUMMARY OF CHANGESCommittee D16 has identified the location of se
48、lected changes to this standard since the last issue (D848 09)that may impact the use of this standard. (Approved February 1, 2014.)(1) Revised Sections 11.3 and 15.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this
49、 standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Y
