1、Designation: D6258 09 (Reapproved 2014)D6258 17Standard Test Method forDetermination of Solvent Red 164 Dye Concentration inDiesel Fuels1This standard is issued under the fixed designation D6258; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、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. Scope Scope*1.1 This test method covers the procedure for determining the concentration of dye Solvent
3、 Red 164 in commercially availablediesel and burner fuels using visible spectroscopy.NOTE 1This test method is suitable for all No. 1 and No. 2 grades in Specifications D396 and D975 and for grades DMA and DMB in SpecificationD2069.1.2 The concentration ranges specified for the calibration standards
4、 are established in response to the Internal Revenue Servicedyeing requirements which state that tax-exempt diesel fuel satisfies the dyeing requirement only if it contains the dye Solvent Red164 (and no other dye) at a concentration spectrally equivalent to 3.9 lb of the solid dye standard Solvent
5、Red 26 per thousandbbl (11.1 mg/L) of diesel fuel.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the respons
6、ibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the D
7、ecision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D396 Specification for Fuel OilsD975 Specification for Diesel Fuel OilsD2069 S
8、pecification for Marine Fuels (Withdrawn 2003)3D3699 Specification for KerosineD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsE131 Terminology Relating to Molecular SpectroscopyE169 Practices for General Techniques of Ultraviolet-Visible Quantitative AnalysisE275 Practice for
9、Describing and Measuring Performance of Ultraviolet and Visible SpectrophotometersE288 Specification for Laboratory Glass Volumetric FlasksE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE969 Specification for Glass Volumetric (Transfer) Pipets2.2 Fed
10、eral Regulation:26 CFR 48.4082-1(b) Federal Excise Tax Regulation3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, refer to Terminology E131.1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and
11、is the direct responsibility of SubcommitteeD02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved May 1, 2014May 1, 2017. Published July 2014May 2017. Originally approved in 1998. Last previous edition approved in 20092014 asD6258 09.D6258 09 (2014). DOI: 10.1520
12、/D6258-09R14.10.1520/D6258-17.2 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 standards Document Summary page on the ASTM website.3 The last approved version of
13、this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes a
14、ccurately, 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 official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Har
15、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 The absorbance of each sample is recorded over a specified wavelength range, and the scan is analyzed using derivativeanalysis software to determine the dye concentration.4.2 Derivative analysis meth
16、odology is employed to minimize interferences caused by variations in the color and compositionof the fuel samples regularly tested using this test method.4.2.1 Naturally occurring diesel test fuels range in color from water white to nearly black, and many of the samples tested usingthis test method
17、 have also had used oils and other products blended with them. These variations in color and composition havea significant effect upon absorbance characteristics of the samples in the region of the visible spectrum where azo dyes absorb.Standard operating procedures to correct for these background v
18、ariations would involve running a neat (undyed) sample andsubtracting out the background absorbance. In most situations involved with the application of this test method, however, neatmaterial is not available, so no background corrections can be made.4.2.2 The second derivative of the absorbance of
19、 these dyes in the visible region is a function of the fine structure of the dyesabsorbance peak (versus its height or area) and is relatively unaffected by changes in background absorbance. Further, the specificsections (maxima and minima) of the second derivative spectra employed for this analysis
20、 are a function of the fine structure ofthe top of the absorbance curve which has been found to be unique to the azo dyes.5. Significance and Use5.1 This test method was developed to provide for the enforcement of 26 CFR 48.4082-1(b), which mandates that all tax-exemptdiesel fuels be dyed with an am
21、ount of Solvent Red 164 at a concentration that is spectrally equivalent to 3.9 3.9 lblb/10103 bbl(11.1 mg/L) of Solvent Red 26. It is employed to verify that the correct amount of Solvent Red 164 is being added to tax-exemptproduct at terminals or refineries prior to sale, and to detect the presenc
22、e of Solvent Red 164 in taxed product intended for on-roaduse.5.1.1 Solvent Red 26 is the azo dye shown in Fig. 1. It is the standard against which the concentration of Solvent Red 164 ismeasured because it is available in a certified pure form. Solvent Red 164 is identical in structure to Solvent R
23、ed 26 except thatit has hydrocarbon (alkyl) chains incorporated to increase its solubility in diesel and burner fuels. The exact composition of SolventRed 164 will vary from manufacturer to manufacturer and lot to lot depending upon the extent of alkylation that occurs duringproduction; however, its
24、 visible spectrum is virtually identical to the spectrum of Solvent Red 26. Solvent Red 164 is employedin the field (instead of Solvent Red 26) to dye tax-exempt diesel and burner fuels because of its higher solubility and relativelylow cost.6. Apparatus6.1 Spectrophotometer, equipped with automated
25、 scanning, background correction, and electronic data storage capabilities, andthe ability to automatically record absorbance or transmittance of solutions in the spectral region from 400 to 800 nanometers (nm)400 nanometers (nm) to 800 nm with a spectral slit width of 1.0 nm 1.0 nm or less (Note 2)
26、. Wavelength measurements shall berepeatable and known to be accurate to within 60.2 nm or less at deuterium peak 656.1 nm. In the absorbance range from 0.01to 1.0, absorbance measurements shall have a photometric accuracy of 60.005 or less and a photometric repeatability of 60.002or less.FIG. 1 Str
27、ucture of Solvent Red 26D6258 172NOTE 2Instruments having different specifications, for example, minimum slit width 22 nm to 4 nm, no data storage, diode array spectrophotometers,and so forth, may be used if they provide demonstrably equivalent results. Equivalence can be demonstrated by successful
28、(within reproducibility limits)participation in inter- or intra-laboratory studies using this test method.6.1.1 For applicable general techniques and methods of testing spectrophotometers to be used in this test method, refer toPractices E169 and E275.6.2 Sample Cells (Cuvettes), one or more fused s
29、ilica or glass cells having sample path length of 1.0 cm.6.3 Analytical Balance, 0.1 mg sensitivity, 60.05 mg precision.6.4 Volumetric Pipettes, 1, 2, 3, 4, and 5 mL, Class A, according to Specification E969.6.5 Volumetric Flasks, 100 mL and 250 mL, Class A, borosilicate glass, according to Specific
30、ation E288.7. Reagents7.1 Purity of ReagentsReagent grade Reagent-grade chemicals shall be used in all tests. Unless otherwise indicated, it isintended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American ChemicalSociety where such specificati
31、ons are available.4 Other grades may be used, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening the accuracy of the determination.7.2 Solvent Red 26 (Dye Standard)Dye, Color Index Solvent Red 26, 1-2,5-dimethyl-4-(2-methylphenyl) azop
32、henylazo-2-naphthol, Chemical Abstract Services Registry No. 4477-79-6, dry powder with certified purity, and maximum absorbance at512512 nm 6 20 nm.7.3 Kerosine1-K, water-white, conforming to Specification D3699, and having a maximum absorbance against air of 0.08absorbance units over the wavelengt
33、h range 450450 nm to 750 nm (1.0 cm cell, 120 nm/min scan rate, slit width 1.0 nm).(WarningFlammable; harmful if swallowed, inhaled, or brought into contact with skin or eyes.)7.4 Xylene(WarningExtremely flammable; harmful if swallowed, inhaled, or brought into contact with skin or eyes.)8. Sampling
34、8.1 Use the principles of Practice D4057 in acquisition of test sample(s).8.2 Precautions must be taken to shield the samples from sunlight prior to analysis.NOTE 3Studies have shown that exposure to direct sunlight will show a decrease in dye concentration over time.9. Calibration and Standardizati
35、on9.1 Preparation of Stock Standard:9.1.1 Solvent Red 26Weigh approximately 0.0750 g of the dye standard to the nearest 0.1 mg on an analytical balance,quantitatively transfer the dye to a 250 mL volumetric flask, and dilute to mark with xylene. Mix the prepared solution thoroughly.9.1.2 Determine t
36、he exact concentration of dye in the stock standard using the following equation:C 5M! P! 1000!0.250 (1)where:C = concentration of active dye ingredient in the stock standard, mg/L,M = mass of certified dye standard used in preparing the stock standard, g, andP = purity of certified dye standard use
37、d in preparing the stock standard, purity %/100, for example, for a 99.0 % Solvent Red26 material, P = 0.99.P = purity of certified dye standard used in preparing the stock standard, purity %/100, for example, for a 99.0 % Solvent Red26 material, P = 0.99.9.1.3 Store the stock standard in tightly ca
38、pped/sealed brown glass bottles and store in a dark place when not in use to preventdeterioration.9.2 Preparation of Working Calibration Standards:9.2.1 Pipet the volumes of the stock standard specified below into separate 100 mL volumetric flasks and dilute to volume withkerosine.4 Reagent Chemical
39、s, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
40、Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D6258 173Volume of Stock Approximate ConcentrationStandard/100 mL of Working Standards0.0 mL 0 mg/L1.0 mL 3 mg/L2.0 mL 6 mg/L3.0 mL 9 mg/L4.0 mL 12 mg/L5.0 mL 15 mg/L9.2.2 Determine the exact concentration of dye in each working st
41、andard using the following equation:Cs5V!Cm!100 (2)where:Cs = concentration of each working standard, mg/L,V = volume of stock standard, mL, andCm = concentration of active dye in stock standard, mg/L.9.2.3 Store the working calibration standards in tightly capped/sealed brown glass bottles and stor
42、e in a dark place when notin use to prevent deterioration.9.3 Using a clean 1.0 cm sample cell, scan each of the working standards against air (empty reference sample compartment)from 450 nm to 750 nm, recording the absorbance for each using a scan rate of 120 nm/min, maximum data recording interval
43、of 0.11 nm, and a maximum slit width of 1.0 nm.NOTE 4Other instrument conditions may be used if they can be demonstrated to give equivalent results to this test method (see Note 2).9.4 Using derivative analysis software, calculate and plot the second derivative spectra for each standard over this wa
44、velengthrange using an instrument noise level dampening setting of sufficient level to provide a smooth second derivative curve.9.5 Measure the amplitude difference for the maximum and minimum listed below:Solvent Red 26: 538 nm 20 nm (peak max, Fig. 2)561 nm 20 nm (peak min, Fig. 2)NOTE 5Specific a
45、mplitude units employed will vary, depending on instrumentation or software used, or both.10. Procedure10.1 Using a clean 1.0 cm sample cell, scan the sample against air (empty reference sample compartment) from 450 nm to750 nm using the same instrument settings employed for the working standards an
46、d record the absorbance.10.2 Using derivative analysis software and the same noise level dampening settings used in 9.4, calculate and plot the secondderivative spectrum of the sample.10.3 Measure the amplitude difference between the derivative maximum and minimum specified in 9.5 (see Note 5).FIG.
47、2 Second Derivative Scans of Solvent Red 26 Dye in KerosineD6258 17410.3.1 The wavelengths of the derivative minima and maxima for the dye in actual diesel fuel samples normally vary from thoseobserved for the working standards due to variations in the composition of the Solvent Red 164 dye used and
48、 sample matrix effects.On instruments that automatically record amplitudes at preset wavelengths, adjustments must be made to compensate for this shiftto ensure that actual minimum and maximum amplitudes are used in determining amplitude differences.11. Calculation11.1 Prepare a calibration curve, p
49、lotting the amplitude difference for each working calibration standard on the y axis versusthe dye concentration on the x axis.11.2 Determine the concentration of dye in the sample by comparing the amplitude difference measured in 10.3 for the sampleagainst the calibration curve.11.2.1 Computer systems/software having appropriate multipoint calibration program capabilities may be used instead of amanual interpolation from calibration curves.11.3 Report the dye concentration results for the sample in mg/L to one decimal place, for example, 11.1 mg
