ASTM D5762-2018a Standard Test Method for Nitrogen in Liquid Hydrocarbons Petroleum and Petroleum Products by Boat-Inlet Chemiluminescence.pdf

1、Designation: D5762 18D5762 18aStandard Test Method forNitrogen in Liquid Hydrocarbons, Petroleum and PetroleumProducts by Boat-Inlet Chemiluminescence1This standard is issued under the fixed designation D5762; the number immediately following the designation indicates the year oforiginal adoption or

2、, 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 nitrogen in liquid hydrocarbons,

3、including petroleum process streams andlubricating oils in the concentration range from 40 gg to 10 000 gg nitrogen. For light hydrocarbons containing less than100 gg nitrogen, Test Method D4629 can be more appropriate.1.2 The values stated in SI units are to be regarded as standard. No other units

4、of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicab

5、ility ofregulatory limitations prior to use. Specific warning statements are given in Section 6, 7.1, 8.2, and 8.2.2.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development

6、of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum

7、 and Petroleum ProductsD4629 Test Method forTrace Nitrogen in Liquid Hydrocarbons by Syringe/Inlet Oxidative Combustion and ChemiluminescenceDetectionD6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-ment System Performance3. Sum

8、mary of Test Method3.1 A hydrocarbon sample is placed on a sample boat at room temperature. The sample and boat are advanced into ahigh-temperature combustion tube where the nitrogen is oxidized to nitric oxide (NO) in an oxygen atmosphere. The NO contactsozone and is converted to excited nitrogen d

9、ioxide (NO2). The light emitted as the excited NO2 decays is detected by aphotomultiplier tube, and the resulting signal is a measure of the nitrogen contained in the sample.4. Significance and Use4.1 Many nitrogen compounds can contaminate refinery catalysts. They tend to be the most difficult clas

10、s of compounds tohydrogenate, so the nitrogen content remaining in the product of a hydrotreator is a measure of the effectiveness of thehydrotreating process. In lubricating oils the concentration of nitrogen is a measure of the presence of nitrogen containingadditives. This test method is intended

11、 for use in plant control and in research.5. Apparatus5.1 Boat Inlet System, capable of being sealed to the inlet of the combustion tube and swept with inert gas. The boats arefabricated from platinum or quartz. To aid quantitative liquid injection, it is recommended to add a small piece of quartz w

12、ool or1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved April 1, 2018Oct. 1, 2018. Published April 2018October 2018. Originally ap

13、proved in 1995. Last previous edition approved in 2017 as 20178asD5762 17.18. DOI: 10.1520/D5762-18.10.1520/D5762-18A.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

14、 the standards Document Summary page on the ASTM website.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

15、 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 official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr H

16、arbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1suitable equivalent (see 6.8) to the boat. The boat drive mechanism should be able to fully insert the boat into the furnace tubeinlet section. A drive mechanism that advances and withdraws the sample boat into and out of the

17、furnace at a controlled andrepeatable rate is required.5.2 Chemiluminescence Detector, capable of measuring light emitted from the reaction between nitric oxide and ozone, andcontaining a variable attenuation amplifier, integrator, and readout.NOTE 1Detectors designed to maintain the chemiluminescen

18、ce reaction cell at reduced pressure are acceptable for use and were included in theinstruments used to determine the precision of this test method.5.3 Combustion Tube, fabricated from quartz. The inlet end of the tube shall be large enough to accept the sample boat and tohave side arms for introduc

19、tion of oxygen and inert gas. The construction is such that the carrier gases sweep the inlet zonetransporting all of the volatilized sample into a high-temperature oxidation zone. The oxidation section should be large enough toensure complete oxidation of the sample.5.4 Drier Tube, for the removal

20、of water vapor. The reaction products include water vapor that shall be eliminated prior tomeasurement by the detector. This can be accomplished with a magnesium perchlorate, Mg(ClO4)2, scrubber, a membrane dryingtube permeation drier, or a chilled dehumidifier assembly.5.5 Furnace, Electric, held a

21、t a temperature sufficient to pyrolyze all of the sample and oxidize the nitrogen to NO. Thefollowing furnace designs may be used. All furnace assemblies include a method for gas flow control, such as needle valves, flowrestrictors or mass flow controllers. Furnaces that are operated at temperatures

22、 below 1050 C shall be capable of switching to100 % oxygen carrier gas flow after the boat has been fully extended into the furnace.5.5.1 Single-zone tube furnace with temperature controller capable of maintaining a stable furnace temperature of 1100 C 625 C.5.5.2 Two-zone tube furnace with temperat

23、ure controllers capable of maintaining the temperature of each furnace zoneindependently from 950 C to 1050 C (see 5.5). Or two-zone tube furnace equipped with the ability to change to a pure oxygencarrier gas flow after the boat is fully extended in to the furnace and temperature controllers capabl

24、e of maintaining the temperatureof each furnace zone independently to 950 C.5.6 Microlitre Syringe, of 5 L or 10 L capacity, capable of accurately delivering microlitre quantities.5.7 Ozone Generator, to supply ozone to the detector reaction cell.5.8 Recorder (Optional), for display of chemiluminesc

25、ence detector signal.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society wheresuch s

26、pecifications are available.3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of the determination.6.2 Acridine, C13H9N, molecular weight 179.21, 7.82 % by mass nitrogen. (WarningIrritant.)6.3

27、Oxidation Catalyst: Cupric Oxide Wire, CuO, or Platinum Catalyst, PtAl2O3, as recommended by the instrumentmanufacturer.6.4 Inert GasArgon or Helium only, high-purity grade (that is, chromatographic or zero grade), 99.998 % minimum purity,5 ppm maximum moisture.6.5 Anhydrous Magnesium Perchlorate, M

28、g(ClO4)2, for drying products of combustion (if permeation drier or chilled drier isnot used). (WarningStrong oxidizer, irritant.)6.6 Nitrogen Stock Solution, 500 ng nitrogen/L. See 6.6.1.6.6.1 Calibration standards from commercial sources may be used if they conform to the requirements of the test

29、method.6.6.2 Volumetric PreparationAccurately weigh (to the nearest 0.1 mg) approximately 0.64 g of acridine into a tared 100 mLvolumetric flask. Add xylene to dissolve, then dilute to volume with xylene. Calculate the nitrogen content of the stock solutionto the nearest milligram of nitrogen per li

30、tre. This stock can be further diluted to desired nitrogen concentrations. (WarningRemake standard solutions on a regular basis depending upon frequency of use and age. Typically, standards have a useful life ofapproximately three months.)6.6.3 Gravimetric PreparationAccurately weigh (to the nearest

31、 0.1 mg) approximately 0.74 g of acridine into a taredcontainer. Add xylene to dissolve, then add xylene to an approximate weight of 100 g with xylene. Calculate the nitrogen contentof the stock solution to the nearest milligram of nitrogen per kilogram. Convert the concentration to milligrams of ni

32、trogen per3 Reagent Chemicals, 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 Stat

33、es Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D5762 18a2litre by multiplying by the density of xylene. This stock can be further diluted to desired nitrogen concentrations.(WarningRemake standard solutions on a regular basis depending upon frequency

34、 of use and age. Typically, standards have auseful life of approximately three months.)6.7 Oxygen, high-purity grade (that is, chromatographic or zero grade), 99.75 % minimum purity, 5 ppm maximum moisture,dried over molecular sieves. (WarningVigorously accelerates combustion.)6.8 Quartz Wool (optio

35、nal), or other suitable absorbent material that is stable and capable of withstanding temperatures insidethe furnace (see Note 2).NOTE 2Materials meeting the requirements in 6.8 are recommended to be used in sample boats to provide a more uniform injection of the sampleinto the boat by wicking any r

36、emaining drops of the sample from the tip of the syringe needle prior to introduction of the sample into the furnace. Consultinstrument manufacturer recommendations for further guidance.6.9 Silver Wool, as recommended by the instrument manufacturer.6.10 Xylene. (WarningFlammable, health hazard.)6.11

37、 Calibration Check Sample(s)portions of one or more liquid petroleum or product standards of known nitrogen contentand not used in the generation of the calibration curve. A calibration check sample or samples shall be used to verify the validityof the calibration curve as described in Section 10.6.

38、12 Quality Control (QC) Sample(s)preferably portions of one or more liquid petroleum materials that are stable andrepresentative of the samples of interest. These QC samples can be used to verify that the testing process is in statistical controlas described in Section 10.7. Sampling7.1 Obtain a tes

39、t sample in accordance with Practice D4057 or D4177. (WarningSamples that are collected at temperaturesbelow room temperature can undergo expansion at laboratory temperatures and rupture the container. For such samples, do not fillthe container to the top. Leave sufficient air space above the sample

40、 to allow room for expansion.) (WarningTo minimize lossof volatile components, which can be present in some test samples, do not uncover any longer than necessary. Test samples shouldbe analyzed as soon as possible after taking from bulk supplies to prevent loss of nitrogen or contamination due to e

41、xposure orcontact with sample container.)7.2 If the test sample is not used immediately, then thoroughly mix it in its container prior to taking a test specimen. Some testsamples require heating in order to thoroughly homogenize.8. Preparation of Apparatus8.1 Assemble apparatus in accordance with th

42、e manufacturers instructions.8.2 Adjust the oxygen flow for the ozone generator in accordance with the manufacturers instructions. Adjust the combustiontube gas flows and the pyrolysis temperature to the recommended operating conditions using the following guidelines for eachfurnace type. (WarningOz

43、one is extremely toxic. Make sure that appropriate steps are taken to prevent discharge of ozonewithin the laboratory work area.)8.2.1 For the single-zone furnace without the ability to change to a pure oxygen carrier gas flow after the boat has been fullyextended into the furnace, adjust the combus

44、tion tube gas flows to the following values: pyrolysis oxygen, 360 mLmin 636 mLmin; inlet oxygen, 60 mLmin 6 6 mLmin; and inert carrier inlet, 155 mLmin 6 15 mLmin. Other gas flows may beused if it can be shown that precision and bias are not degraded. Set the furnace temperature to 1100 C 6 25 C. A

45、djust the boatdrive mechanism to obtain a drive rate of 150 mmmin 6 10 mmmin. Refer to the manufacturers instructions for descriptionsof these settings.8.2.2 For the two-zone furnace without the ability to change to a pure oxygen carrier gas flow after the boat has been fullyextended into the furnac

46、e, adjust the combustion tube gas flows to the following values: combustion oxygen, 165 mLmin616 mLmin; inlet inert carrier, 85 mLmin 6 9 mLmin; and boat inert carrier, 50 mLmin 6 5 mLmin. Other gas flows maybe used if it can be shown that precision and bias are not degraded. Set the inlet furnace t

47、emperature to 1050 C 6 25 C, and theoutlet furnace temperature to 925 C 6 25 C. Adjust the boat drive mechanism to obtain a drive rate of 150 mmmin 610 mmmin (boat speed number 4). Refer to the manufacturers instructions for the description of these settings. (WarningHightemperature is employed in t

48、his test method. Use flammable materials with care near the pyrolysis furnace.)8.2.3 For the two-zone furnace with the ability to change to a pure oxygen carrier gas flow after the boat has been fully extendedin to the furnace, adjust the combustion tube gas flows to the following values: main oxyge

49、n, 400 mLmin 6 40 mLmin; inletargon carrier, 0.4 Lmin 6 0.04 Lmin, and inlet oxygen carrier, 0.4 Lmin 6 0.04 Lmin. Other gas flows may be used if it canbe shown that precision and bias are not degraded. Set the inlet furnace temperature to 600 C 6 25 C, and the outlet (catalyst)temperature to 950 C 6 25 C. Set the automatic boat control as follows: 1 Fuc FWD 125 speed 10 time 30, 2 Fuc 285 speed05 time 30, 5 Fuc time 30, 6 Fuc time 90,AFuc time 60. Refer to manufacturers instructions for a description of these s