ASTM D7183-2018a Standard Test Method for Determination of Total Sulfur in Aromatic Hydrocarbons and Related Chemicals by Ultraviolet Fluorescence.pdf

1、Designation: D7183 18D7183 18aStandard Test Method forDetermination of Total Sulfur in Aromatic Hydrocarbons andRelated Chemicals by Ultraviolet Fluorescence1This standard is issued under the fixed designation D7183; the number immediately following the designation indicates the year oforiginal adop

2、tion 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 sulfur in aromatic hydroca

3、rbons, their derivatives, and related chemicals.1.2 This test method is applicable to samples with sulfur concentrations to 10 mg/kg.The limit of detection (LOD) is 0.03 mg/kgS and the limit of quantitation (LOQ) is 0.1 mg/kg S. With careful analytical technique, this method can be used to successfu

4、llyanalyze concentrations below the current scope (see Appendix X1).NOTE 1LOD and LOQ were calculated using data in ASTM Research Report RR:D16-1060.1.3 The following applies for the purposes of determining the conformance of the test results using this test method to applicablespecifications, resul

5、ts shall be rounded off in accordance with the rounding-off method of Practice E29.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associate

6、d with its use. It is the responsibilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use. For specific hazard statements, see Section 9.1.6 This international standard was developed

7、 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 Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.

8、1 ASTM Standards:2D1555 Test Method for Calculation of Volume and Weight of Industrial Aromatic Hydrocarbons and CyclohexaneD3437 Practice for Sampling and Handling Liquid Cyclic ProductsD6809 Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related MaterialsE

9、29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method2.2 Other DocumentsOSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.1200 33. Terminology3.1 oxidati

10、ve pyrolysis, na process in which a sample is combusted in an oxygen-rich atmosphere at high temperature to breakdown the components of the sample into elemental oxides.3.2 ultraviolet fluorescence, nradiation in the region of the electromagnetic spectrum including wavelength from 100 to3900A that e

11、xcites SO2 to (SO2*).4. Summary of Test Method4.1 A specimen is either directly injected or placed in a sample boat. The boat is then inserted into a high temperaturecombustion tube where the sulfur is oxidized to sulfur dioxide (SO2) in an oxygen-rich atmosphere. Water produced during the1 This tes

12、t method is under the jurisdiction of ASTM Committee D16 on Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsibility ofSubcommittee D16.04 on Instrumental Analysis.Current edition approved June 1, 2018Nov. 1, 2018. Published June 2018November 2018. Originally approved i

13、n 2007. Last previous edition approved in 20162018 asD7183 16. DOI: 10.1520/D7183-18.10.1520/D7183-18a.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

14、Document Summary page on the 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 sta

15、ndard an indication of what 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 AS

16、TM is to be considered the 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 States1sample combustion is removed and the sample combustion gases are next expose

17、d to ultraviolet (UV) light. The SO2 absorbs theenergy from the UV light and is converted to excited sulfur dioxide (SO2*). As it returns to a stable state, light is emitted anddetected by a photomultiplier tube and the resulting signal is a measure of the sulfur contained in the specimen.5. Signifi

18、cance and Use5.1 Some process catalysts used in petroleum and chemical refining can be poisoned when trace amounts of sulfur-bearingmaterials are contained in the feedstocks. This test method can be used to determine sulfur in process feeds, sulfur in finishedproducts, and can also be used for purpo

19、ses of regulatory control.6. Interferences6.1 Halogens present in the specimen in concentrations greater than 10% and nitrogen concentrations of 1500 mg/kg or greatercan interfere.6.2 Moisture produced during the combustion step can interfere if not removed prior to the gas entering the detector cel

20、l.7. Apparatus7.1 Combustion FurnaceAn electric furnace capable of maintaining a temperature sufficient to volatilize and combust all thesample and oxidize sulfur to SO2. The actual temperature should be recommended by specific instrument manufacturer.7.2 Quartz Combustion TubeCapable of withstandin

21、g 900 to 1200C. The tube should be recommended by the instrumentmanufacturer.7.3 Microlitre SyringeCapable of delivering from 5 to 250 L of sample. Check with the instrument manufacturer forrecommendations for specific sample requirements.7.4 Constant Rate Injector SystemIf the sample is to be intro

22、duced into the pyrolysis furnace via syringe, use a constant rateinjector or a liquid introduction module.7.5 Liquid Auto-SamplerCapable of injecting 5 to 250 L of sample.7.6 Automatic Boat Drive SystemIf the instrument is equipped with an inlet system, a device for driving the boat into thefurnace

23、at a controlled and repeatable rate is required.7.7 Flow ControlThe instrument must be equipped with a means of flow control capable of maintaining a constant supply ofoxygen and carrier gas or air.7.8 Drier TubeThe instrument must be equipped with a mechanism for removal of water vapor.8. Reagents8

24、1 Purity of ReagentsReagent grade chemicals shall be used in all tests. It is intended that all reagents shall conform to thespecifications of the Committee on Analytical Reagents of the American Chemical Society,4 where such specifications areavailable, unless otherwise indicated. Other grades may

25、 be used, provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy of the determination.8.2 Inert Gas or AirEither argon (Ar), helium (He) or air may be used. The purity should be no less than 99.99%.8.3 Oxygen Gas (as required)

26、The purity should be no less than 99.99%.8.4 SolventThe solvent chosen should be capable of dissolving the sulfur compound. The solvent of choice should have aboiling point similar to the sample being analyzed. Suggested possibilities include, but not limited to methanol, iso-octane, andp-xylene (se

27、e Note 2 and Note 3).NOTE 2A quick screening can be conducted by injecting the solvent and sample once or twice and comparing relative area counts.NOTE 3All solvents should have known sulfur content or known to be less than what will interfere with results.8.5 DibenzothiopheneFW184.26, 17.399% (m/m)

28、 Sulfur (see Note 4).NOTE 4A correction for chemical impurity is required. Normally 98%.8.6 Quartz WoolIf needed.8.7 Sulfur Stock Solution, approximately 870 to 1044 g S/mlThis standard may be purchased if desired. Prepare a stocksolution by accurately weighing approximately 0.5 to 0.6 g of dibenzot

29、hiophene to the nearest 0.1 mg into a tared 100 mLvolumetric flask. Record the weight. Dilute to volume with the selected solvent. Use Eq 1 to determine the concentration of stock4 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions

30、 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, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D7183 18a2solution. This stock sol

31、ution can be further diluted to desired sulfur concentrations (see Note 5 and Note 6). Alternate volumes ofsolutions may be prepared so long as the preparation meets the concentration specified.g S/ml solvent5g of DBT!3.174!3Purity of DBT!3106!100 ml of Solvent (1)where:DBT = dibenzothiopheneS in DB

32、T = 17.3994%NOTE 5Working standards should be remixed on a regular basis depending upon frequency of use and age. Typically, stock solutions have a usefullife of about 3 months.NOTE 6Check all new calibration standards against the previous standard.8.8 Oxidation Reagent (as required)Tungsten trioxid

33、e, (WO3), granular (typical particle size 2.0 mm), high purity, 99.75%minimum.9. Hazards9.1 Consult the current version OSHA regulations, suppliers Data Sheets, and local regulations for all materials used in thistest method.9.2 High temperature is employed in this test method. Extra care must be ex

34、ercised when using flammable materials near thefurnace.9.3 WarningExposure to excessive quantities of ultraviolet light is injurious to health. The operator must avoid exposing anypart of their person, especially their eyes, not only to direct UV light but also to secondary or scattered radiation th

35、at is present.10. Sampling10.1 Consult guidelines for taking samples from bulk containers in accordance with Practice D3437.11. Preparation of Apparatus11.1 Set-up the instrument in accordance with manufacturers instructions.11.2 Adjust gas flows and pyrolysis temperature(s) to the operating conditi

36、ons recommended by the manufacturer.11.3 The actual operation of injecting a sample will vary depending upon the instrument manufacturer and the type of inletsystem used.11.4 An autosampler or a constant rate injector must be used when using an instrument equipped with a vertical furnace.11.5 Prebak

37、e the sample boats to be used for the determination when using a horizontal furnace.12. Calibration and Standardization12.1 Using the sulfur standard stock solution (see 8.7), make a series of calibrations standards covering the range of expectedsulfur concentration.NOTE 7When looking for levels of

38、sulfur below 1 mg/kg make a calibration curve using an autosampler or constant rate injector and standards, madefrom the sulfur stock solution, to cover the expected range of samples. Follow manufacturers recommendations for constructing the curve.NOTE 8When looking for concentrations from 1 mg S/kg

39、 to 10 mg S/kg, follow manufacturers recommendations for constructing the curve.12.2 The sample size can be determined either volumetrically, by syringe or by mass.12.3 Volumetric measurement can be utilized by filling the syringe with standard, carefully eliminating all bubbles, and pushingthe plun

40、ger to a calibrated mark on the syringe, and recording the volume of liquid in the syringe.After injecting the standard, readthe volume remaining in the syringe. The difference between the two volume readings is the volume of standard injected. This testmethod requires the known or measured density,

41、 to the third decimal place.12.4 Alternatively, the syringe may be weighed before and after the injection to determine the weight of the sample injected.This technique provides greater precision than the volume delivery method, provided a balance with a precision of 60.0001 g isused.12.5 Follow the

42、instrument manufacturers recommendation for introducing samples into the instrument.12.6 If there are any problems with the calibration standards follow the instrument manufacturers recommendations to correct.12.7 Construct a linear regression curve (g S versus Area) using as many points as recommen

43、ded by the instrumentmanufacturer.12.8 The linear regression curve should have a minimum of 0.99 correlation coefficient. If it does not, examine each point onthe curve to determine which point or points are out. Correct the problem and run new Standards.D7183 18a313. Procedure13.1 Obtain a test spe

44、cimen using the procedure described in Section 10. The sulfur concentration in the test specimen must beless than the concentration of the highest standard and greater than the concentration of the lowest standard used in the calibration.13.2 Follow the instrument manufacturers recommendations for s

45、ample size.13.3 Follow the instrument manufacturers recommendations for introducing samples into the instrument.13.4 Determine the sulfur concentration, by the average of three determinations, calculated by the instrument software. Makesure replicates are repeatable.14. Calculation14.1 All calculati

46、ons are performed by the software, and results are displayed and printed out in ppm (mg/kg) as appropriate.The density is input during sample data entry and is used by the instrument to convert from wt./vol. to wt./wt.14.2 Use Test Method D1555 for measurements utilizing volume and known density in

47、milligrams per kilograms as follows:Sulfur,mg/kg5M 2B!V 3D (2)14.3 Measurement utilizing weight of sample:sulfur,mg/kg5M 2B!w (3)where:M = measured sulfur value, gB = blank measured sulfur value, gV = sample injection volume, mLD = density of sample g/mLw = weight of sample, g15. Report15.1 Report t

48、he sulfur results as (mg/kg ) (mg/kg) of the sample to the nearest 0.01 mg/kg for samples less than 1 mg/kg. Reportto the nearest 0.1 for samples greater than 1 mg/kg.15.1.1 Results below 0.3 mg/kg should be reported as 0.03 mg/kg.16. Precision and Bias516.1 An ILS was conducted which included eleve

49、n laboratories analyzing ten samples two times. Practice E691 was followedfor the design and analysis of the data; the details are given in ASTM Research Report RR:D16-1060.16.1.1 Repeatability Limit (r)Results should not be suspect unless they differ by more than shown in Table 1. Results differingby less than (r) have a 95% probability of being correct.16.1.2 Reproducibility Limit (R)Results submitted by two laboratories should not be considered suspect unless they differ bymore than shown in Table 1. Results differing by les