ASTM_D_7058_-_19.pdf

Designation:D705819Standard Test Method forDetermination of the Red Dye Concentration and Estimationof Saybolt Color of Aviation Turbine Fuels and KerosineUsing a Portable Visible Spectrophotometer1This standard is issued under the fixed designation D7058;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.Scope*1.1 This test method covers the determination of the red dyeconcentration of aviation turbine fuel and kerosine and theestimation of the Saybolt color of undyed and red dyed(0.180 mg L).The bias for the base fuels was within the standard error of TestMethod D156.13.5 The precision statements in 13.1 were derived from the1997 interlaboratory test program.Participants analyzed sevensets of undyed base fuels and 13 sets of dyed base fuel/colorcombinations in duplicate in the Saybolt color range of 16 to+30 and dye concentration from 0 mg L to 0.374 mg L,sevenlaboratories participated with the automatic apparatus and fivelaboratories participated with the manual Test Method D156apparatus.514.Keywords14.1 aviation turbine fuel;kerosine;red dye concentration;Saybolt color;visible spectrometry5Supporting data,results of the 1997 Interlaboratory Cooperative Test Program,have been filed at ASTM International Headquarters and may be obtained byrequesting Research Report RR:D02-1521.Contact ASTM Customer Service atserviceastm.org.D7058 193 ANNEXES(Mandatory Information)A1.PROCEDURE FOR PREPARATION OF RED DYE/SAYBOLT COLOR STANDARDS,QUALIFICATION SAMPLES,AND QUALITY CONTROL SAMPLESA1.1 ScopeA1.1.1 This annex is a description of the preparation of dyeconcentration and color standard samples used for calibrationand qualification.It also describes the preparation of possiblestandard samples that can be used for periodic checks.A1.2 ApparatusA1.2.1 Spectrophotometer,equipped to measure the absor-bance of solutions in the spectral region from 380 nm to780 nm with an effective spectral slit width of 10 nm 6 2 nmor 5 nm 6 1 nm.Wavelength measurements shall be repeatableand known to be accurate to 0.1 nm.The photometric linearityis to be 60.5%of full scale and a photometric reproducibilityof 60.2%.A1.2.2 Sample Cells,constructed of optical glass or quartzhaving a path length of 1 cm 6 0.001 cm for use with thespectrophotometer described in A1.2.1.A1.2.3 Filter Spectrophotometer,see 7.1.A1.2.4 Sample Cell,see 7.2.For use with the spectropho-tometer described in A1.2.3.A1.2.5 Balance,with a readability of 0.1 mg,or better.A1.2.6 Pipettes,0.5 mL,1 mL,and 2 mL capacity,Class A.A1.2.7 Volumetric Flasks,100 mL,200 mL,and 250 mLcapacity,Class A.A1.2.8 Beaker,50 mL capacity.A1.3 ReagentsA1.3.1 Purity of ReagentsReagent grade chemicals shallbe used in all tests.Unless other wise indicated,it is intendedthat all reagents conform to the specifications of the Committeeon Analytical Reagents of the American Chemical Societywhere such specifications are available.6Other grades may beused,provided it is first asserted that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.A1.3.2 Dyes:A1.3.2.1 3-Methyl-1-(phenyl azo)-pyrazol-5-ol(Yellow5GS-EX),with CAS Registry No.4314-14-1.A1.3.2.2 1-(phenyl azo)-2-naphthalenol(Orange EX),withCAS Registry No.842-07-9.A1.3.2.3 1,4 bis(butylamino)-9,10-anthracenedione(BlueSB),with CAS Registry No.17354-14-2.A1.3.2.4 1-2,5-dimethyl-4(2-methylphenyl)azophenylazo-2-naphthol(Solvent Red 26),with CAS Registry no.4477-79-6.A1.3.3 1,1-bis(3,4-dimethylphenyl)ethane,(90%min pu-rity).A1.3.4 Dodecane,anhydrous(99%min purity).A1.3.5 Xylenes,A.C.S.reagent grade.A1.4 Preparation Procedure for the Saybolt StandardSamplesA1.4.1 Measure 0.2500 g 6 0.0005 g of Yellow 5GS-EXinto a 50 mL beaker and dissolve the dye in 20 mL of1,1-bis(3,4-dimethylphenyl)ethane.Quantitatively transfer theYellow 5GS-EX solution to a 250 mL volumetric flask,diluteto the mark with 1,1-bis(3,4-dimethylphenyl)ethane and mixwell.This solution is called the Yellow 5GS-EX dye solution.A1.4.2 Repeat the above procedure for the Orange EX andBlue SB dyes.These solutions are called Orange EX dyesolution and Blue SB dye solution,respectively.A1.4.3 Pipet 2 mL of the Yellow 5GS-EX solution into a200 mL volumetric flask,dilute to the mark with dodecane andmix well.Using separate flasks repeat this procedure with theOrange EX dye solution and the Blue SB dye solution.A1.4.4 At the wavelengths indicated in TableA1.1,measurethe absorbance of these solutions using the spectrophotometerand cells described in A1.2.1 and A1.2.2,respectively.Usedodecane as the reference material.If the measured absor-bances are not within the indicated ranges,adjust the solutioneither by adding more of the solid dye if the measuredabsorbances are less than the indicated absorbance