1、Designation: D848 14D848 18Standard 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 revis
2、ion. 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. Scope*Scope1.1 This test method covers the determin
3、ation of the acid wash color of benzene, toluene, xylenes, refined solvent naphthas, andsimilar industrial aromatic hydrocarbons.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address
4、 all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use. For specific hazard statements,
5、see Sections 8 and 12.1.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization
6、Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD3437 Practice for Sampling and Handling Liquid Cyclic ProductsD4790 Terminology of Aromatic Hydrocarbons and Related ChemicalsD6809 Guide for Quality Control and Quality Assur
7、ance Procedures for Aromatic Hydrocarbons and Related Materials2.2 Other Document:3OSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.12003. Terminology3.1 See Terminology D4790 for definitions of terms used in this test method.4. Summary of Test Method4.1 A mixture of the aromatic hydrocarbon a
8、nd sulfuric acid is vigorously shaken and the color of the acid layer is comparedwith that of color standards prepared from CoCl2 and FeCl3.5. Significance and Use5.1 This test method is suitable for setting specifications on the materials referenced in 1.1. It may also be used as an internalquality
9、 control tool and in development or research work.5.2 The color developed in the acid layer gives an indication of impurities which if sulfonated would cause the material to bediscolored.1 This test method is under the jurisdiction of ASTM Committee D16 on Aromatic Hydrocarbons Aromatic, Industrial,
10、 Specialty and Related Chemicals and is the directresponsibility of Subcommittee D16.01 on Benzene, Toluene, Xylenes, Cyclohexane and Their Derivatives.Current edition approved Feb. 1, 2014June 1, 2018. Published February 2014June 2018. Originally approved in 1945. Last previous edition approved in
11、20092014 asD848 09.D848 14. DOI: 10.1520/D0848-14.10.1520/D0848-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standardsstandards Document Summary page on th
12、e ASTM website.3 Available 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.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what
13、 changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the
14、official document.*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 States16. Apparatus6.1 Containers for Color StandardsClear and unblemished, clean, French square, flint-glass,
15、 flat-bottom, glass-stoppered,30-mL capacity bottles holding 31 to 33 mL when filled to the neck. The bottles shall be labeled with the reference number of thecolor standard they contain (see 11.2).6.2 Test ContainersContainers exactly like those described in 6.1 except that each French square bottl
16、e shall be marked byetching to show when the bottle contains the volume of 7 and 28 mL, respectively. Colored crayons and similar markers shall notbe used for marking the bottles.7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is in
17、tended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, wheresuch specifications are available.4 Other grades may be used provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use wi
18、thout lessening the accuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean distilled water, Type I or IIas described in Specification D1193.7.3 Cobalt Chloride (CoCl2 6H2O).7.4 Ferric Chloride (FeCl3 6H2O).7.5 Hydrochloric Acid (1
19、 + 39)Mix 25 mL of hydrochloric 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. Hazards8.1 Consult current OSHA regulations, suppliers Material su
20、ppliers Safety Data Sheets, and local regulations for all materialsused in 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 Practice D3437.10. Cleaning of Containers10.1 Clean
21、new containers (Section 6) with a cleaning solution that will not impact the results, such as a chromic acid substitute,rinse with tap water followed by distilled water, and dry in an oven set at a minimum of 105C for at least 1 h. Likewise, cleanall other glassware used in this test method.11. Prep
22、aration of Reference Color StandardsNOTE 1Purchase of solutions or reference color standards, or both, is allowed. The user of this standard assumes the responsibility of ensuring anypurchased solutions or standards are prepared with materials that meet the requirements expressed in the Reagents sec
23、tion of this standard. Likewise, theuser of this standard assumes the responsibility of ensuring any purchased solutions or standards are prepared as expressed in this section.11.1 Stock SolutionsPrepare the following basic reagent solutions for use in preparing the reference color standards:11.1.1
24、Solution ADissolve 59.50 g of CoCl26H2O in HCl (1 + 39) and make up to 1 Lin 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 volumes of Solution A with 3612 volumes
25、 of Solution B and dilute with 90 volumes of water.11.1.4 Solution DMix 312 volumes of Solution A with 3612 volumes of Solution B.11.1.5 Solution EPrepare an aqueous solution of K2CrO4 saturated at 21C.11.1.6 Solution FPrepare an aqueous solution of K2Cr2O7 saturated at 21C and dilute with an equal
26、volume of water.11.2 Prepare reference color standard solutions having the following compositions and numbered as specified below. It is notrequired to make each color standard. Only those reference color standards that bracket the samples being evaluated must beutilized.4 Reagent Chemicals, America
27、n Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary,
28、 U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D848 182No. 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 v
29、olumes of water.No. 6Solution D.No. 75 volumes of Solution E plus 2 volumes of water.No. 8Solution E.No. 97 volumes of Solution E plus 12 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 So
30、lution E plus 1 volume of Solution F.No. 132 volumes of Solution E plus 5 volumes of Solution F.No. 14Solution F.11.3 Rinse the No. 0 container (6.1) and its glass stopper three times with water, fill with water, and stopper. Rinse the No. 1container and its stopper three times with reference color
31、standard solution No. 1 (11.2), fill with this solution, and stopper. In thisway, prepare the set of containers of color standards from 0 through 14 having the compositions shown for the corresponding colorsolution standards in 11.2. When filling the French square bottles, leave 6 mm of vapor space
32、below the neck of the bottle. Sealeach container with paraffin to prevent loss by evaporation or seepage.NOTE 2It is recommended color standards be prepared annually from fresh solutions.12. Procedure12.1 Fill a clean, dry test container to the 7-mL mark with the acid of the strength specified in Ta
33、ble 1 for the type of sampleto be tested . Add sufficient sample to bring the total volume to the 28-mL mark (Note 3). Insert the stopper, hold a finger overthe stopper, and give vigorous shakes with a stroke of 13 to 25 cm, shaking for a total of 150 cycles over a period of 40 to 50 s,that is at a
34、rate of 3 to 3.75 cycles/s. (Use of an automatic shaker is allowed given it can be shown to produce comparable resultsto the manual technique.) (WarningConcentrated sulfuric acid will cause severe burns on contact with the skin.As a precautionthe test container should be wrapped in a towel or enclos
35、ed in a plastic bag during the shaking period. The test should be performedusing appropriate personal protective equipment.)NOTE 3If the room temperature is above 29C, maintain the acid, sample, and reference color standards at a temperature between 25 and 29Cthrough the test, and insulate the test
36、container in some convenient way, such as wrapping with a cloth, during the shaking period.12.2 Allow the container to stand, protected from direct sunlight, for the period of time shown in Table 1. Without further delay,invert the container gently once or twice to obtain a uniform color in the acid
37、 layer, and compare the color of the acid layer withthat of the standards (11.3). Make the comparison against a white background or against daylight, using transmitted light (Note4). When testing samples in Group 1 (Table 1), observe the color of the oil layer as well as that of the acid layer. Stan
38、dards usedshall include standards one number above and one number below the sample, except for the samples reading 0 or 14.NOTE 4Agreement of results may be improved by using a color comparator of a suitable type for observing the color of the acid layer in comparisonwith the reference standard colo
39、r solution.12.3 Designate the color of the acid layer by the number of the nearest matching standard, following the number with a plusor minus sign if the sample is darker or lighter, respectively, than the standard. Disregard any difference in hue and determine onlywhether the color of the acid lay
40、er is darker or lighter than the color of the reference standard to which the sample most nearlycorresponds. If the hue of the acid color is different from the hue of the reference color standard, record the color number followedTABLE 1 Acid Strengths and Standing TimesSampleSulfuricAcidStrength,%St
41、andingTime,minGroup 1 Benzene, all ASTM gradesToluene, all ASTM gradesXylene, nitration gradeXylene, 5Xylene, 10Any other more highly refinedproducts96 15Group 2 Xylene, industrial gradeRefined solvent naphtha96 5Group 3 Hi-flash solventHeavy solvent naphtha78 5D848 183by (X). Thus “No. 4 (X)” means
42、 that the acid wash test color is slightly lighter than No. 4 color standard and that the hue ofthe No. 4 color standard is not the same as the hue of the acid layer.12.4 Dispose of the acid and hydrocarbon properly before cleaning the container. Clean the test container by flushing thoroughlywith w
43、ater (tap grade or better) until traces of acid have been removed. The test container must be completely dry before beingplaced back into use.NOTE 5Suitable solvents, that will not impact the results, may be used after the water rinse step to assist in drying the container.13. Interpretation of Resu
44、lts13.1 Report Group 1 samples (Table 1) as passing the test only when the oil layer shows no change in color and when the acidlayer is not darker than the specified color standard. A cloudiness or haze in the oil layer should not be interpreted as a changein color.13.2 When testing samples of Group
45、s 2 or 3, disregard the color of the oil layer and report the sample as passing the test whenthe acid layer is not darker than the specified color standard.14. Precision and Bias14.1 Precision data have not been established for all types of samples on which this test method is used. Limited cooperat
46、ivetests were conducted in 1961, principally to establish equality with the previously used shaking procedure. Precision estimatestaken from these data are as follows:Repeatability ReproducibilityAverage Acid Wash ColorDegreesofFreedom95 %Repeat-abilityDegreesofFreedom95 %Repro-ducibilityBenzene 1.4
47、6.111120.751.859102.344.47Xylene 4.710.212120.401.1410101.393.5215. Quality Guidelines15.1 Laboratories shall have a quality control system in place.15.1.1 Confirm the performance of the test instrument or test method by analyzing a quality control sample following theguidelines of standard statisti
48、cal quality control practices.15.1.2 Aquality control sample is a stable material isolated from the production process and representative of the sample beinganalyzed.15.1.3 When QA/QC protocols are already established in the testing facility, these protocols are acceptable when they confirmthe valid
49、ity of test results.15.1.4 When there are no QA/QC protocols established in the testing facility, use the guidelines described in Guide D6809 orsimilar statistical quality control practices.16. Keywords16.1 acid wash color; aromatic hydrocarbonsSUMMARY OF CHANGESCommittee D16 has identified the location of selected 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.D848 184ASTM International takes no positio
