1、Designation: D5762 12 (Reapproved 2017)Standard Test Method forNitrogen in Petroleum and Petroleum Products by Boat-InletChemiluminescence1This standard is issued under the fixed designation D5762; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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. Scope1.1 This test method covers the determination of nitrogen inliquid hydrocarbons, including petr
3、oleum process streams andlubricating oils in the concentration range from 40 gg to10 000 gg nitrogen. For light hydrocarbons containing lessthan 100 gg nitrogen, Test Method D4629 can be moreappropriate.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement ar
4、e included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations p
5、rior to use. Specific warningstatements are given in Section 6, 7.1, 8.2, and 8.2.2.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Gui
6、des and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4629 Tes
7、t Method for Trace Nitrogen in Liquid PetroleumHydrocarbons by Syringe/Inlet Oxidative Combustion andChemiluminescence DetectionD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance3. Summary of Test Method3.1 A
8、hydrocarbon sample is placed on a sample boat atroom temperature. The sample and boat are advanced into ahigh-temperature combustion tube where the nitrogen is oxi-dized to nitric oxide (NO) in an oxygen atmosphere. The NOcontacts ozone and is converted to excited nitrogen dioxide(NO2). The light em
9、itted as the excited NO2decays is detectedby a photomultiplier tube, and the resulting signal is a measureof the nitrogen contained in the sample.4. Significance and Use4.1 Many nitrogen compounds can contaminate refinerycatalysts. They tend to be the most difficult class of compoundsto hydrogenate,
10、 so the nitrogen content remaining in theproduct of a hydrotreator is a measure of the effectiveness ofthe hydrotreating process. In lubricating oils the concentrationof nitrogen is a measure of the presence of nitrogen containingadditives. This test method is intended for use in plant controland in
11、 research.5. Apparatus5.1 Boat Inlet System, capable of being sealed to the inlet ofthe combustion tube and swept with inert gas. The boats arefabricated from platinum or quartz. To aid quantitative liquidinjection, it is recommended to add a small piece of quartzwool or suitable equivalent (see 6.8
12、) to the boat. The boat drivemechanism should be able to fully insert the boat into thefurnace tube inlet section. A drive mechanism that advancesand withdraws the sample boat into and out of the furnace at acontrolled and repeatable rate is required.5.2 Chemiluminescence Detector, capable of measur
13、inglight emitted from the reaction between nitric oxide and ozone,and containing a variable attenuation amplifier, integrator, andreadout.NOTE 1Detectors designed to maintain the chemiluminescence reac-tion cell at reduced pressure are acceptable for use and were included inthe instruments used to d
14、etermine the precision of this test method.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved July 1, 2017. Published July 2017. Ori
15、ginally approvedin 1995. Last previous edition approved in 2012 as D5762 12. DOI: 10.1520/D5762-12R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards
16、Document Summary page onthe ASTM website.*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 StatesThis international standard was developed in accordance with internationally reco
17、gnized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.3 Combustion Tube, fabricated from quartz. The inlet endof th
18、e tube shall be large enough to accept the sample boat andto have side arms for introduction of oxygen and inert gas. Theconstruction 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 bel
19、arge enough to ensure complete oxidation of the sample.Combustion tubes recommended for the two furnaces in 5.5.1and 5.5.2 are described in 5.3.1 and 5.3.2. Other configurationsare acceptable if precision and bias are not degraded.5.3.1 Quartz combustion tube for use with the single-zonefurnace is i
20、llustrated in Fig. 1. A water-jacket around the inletsection can be used to cool the boat prior to sample injection.5.3.2 Quartz combustion tube for use with the two-zonefurnace is illustrated in Fig. 2. Fig. 3 illustrates a combustiontube for a two-zone furnace that is equipped with the ability tos
21、witch to a pure oxygen carrier gas flow after the boat has beenfully extended into the furnace (consult the instrument manualto determine if the instrument changes to a pure oxygen carriergas flow after the boat is inserted). The outlet end of thepyrolysis tube is constructed to hold a removable qua
22、rtz inserttube. The removable quartz insert tube is packed with anoxidation catalyst as recommended by the instrument manu-facturer.5.4 Drier Tube, for the removal of water vapor. The reactionproducts include water vapor that shall be eliminated prior tomeasurement by the detector. This can be accom
23、plished with amagnesium perchlorate, Mg(ClO4)2, scrubber, a membranedrying tube permeation drier, or a chilled dehumidifier assem-bly.5.5 Furnace, Electric, held at a temperature sufficient topyrolyze all of the sample and oxidize the nitrogen to NO. Thefollowing furnace designs may be used.All furn
24、ace assembliesinclude a method for gas flow control, such as needle valves,flow restrictors or mass flow controllers. Furnaces that areoperated at temperatures below 1050 C shall be capable ofswitching to 100 % oxygen carrier gas flow after the boat hasbeen fully extended into the furnace.5.5.1 Sing
25、le-zone tube furnace with temperature controllercapable of maintaining a stable furnace temperature of 1100 C6 25 C.5.5.2 Two-zone tube furnace with temperature controllerscapable of maintaining the temperature of each furnace zoneindependently from 950 C to 1050 C (see 5.5). Or two-zonetube furnace
26、 equipped with the ability to change to a pureoxygen carrier gas flow after the boat is fully extended in to thefurnace and temperature controllers capable of maintaining thetemperature of each furnace zone independently to 950 C.5.6 Microlitre Syringe, of 5 Lor 10 Lcapacity, capable ofaccurately de
27、livering microlitre quantities.5.7 Ozone Generator, to supply ozone to the detectorreaction cell.5.8 Recorder (Optional), for display of chemiluminescencedetector signal.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it i
28、s intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Societywhere such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use
29、 without lessening theaccuracy of the determination.6.2 Acridine, C13H9N, molecular weight 179.21, 7.82 % bymass nitrogen. (WarningIrritant.)6.3 Oxidation Catalyst: Cupric Oxide Wire, CuO, or Plati-num Catalyst, PtAl2O3, as recommended by the instrumentmanufacturer.6.4 Inert GasArgon or Helium only,
30、 high-purity grade(that is, chromatographic or zero grade), 99.998 % minimumpurity, 5 ppm maximum moisture.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, se
31、e Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Quartz Combustion Tube (Single-Zone Furnace)D5762 12 (2017)26.5 Anhydrous Magnesium Perchlorate, Mg(ClO
32、4)2, fordrying products of combustion (if permeation drier or chilleddrier is not 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 maybe used if they conform to the requirements of the test method.
33、6.6.2 Volumetric PreparationAccurately weigh (to thenearest 0.1 mg) approximately 0.64 g of acridine into a tared100 mLvolumetric flask.Add xylene to dissolve, then dilute tovolume with xylene. Calculate the nitrogen content of the stocksolution to the nearest milligram of nitrogen per litre. Thisst
34、ock can be further diluted to desired nitrogen concentrations.(WarningRemake standard solutions on a regular basisdepending upon frequency of use and age. Typically, standardshave a useful life of approximately three months.)6.6.3 Gravimetric PreparationAccurately weigh (to thenearest 0.1 mg) approx
35、imately 0.74 g of acridine into a taredcontainer. Add xylene to dissolve, then add xylene to anapproximate weight of 100 g with xylene. Calculate the nitro-gen content of the stock solution to the nearest milligram ofnitrogen per kilogram. Convert the concentration to milligramsof nitrogen per litre
36、 by multiplying by the density of xylene.This stock can be further diluted to desired nitrogen concen-trations. (WarningRemake standard solutions on a regularbasis depending upon frequency of use and age. Typically,standards have a useful life of approximately three months.)6.7 Oxygen, high-purity g
37、rade (that is, chromatographic orzero grade), 99.75 % minimum purity, 5 ppm maximummoisture, dried over molecular sieves. (WarningVigorouslyaccelerates combustion.)FIG. 2 Quartz Combustion Tube (Two-Zone Furnace)FIG. 3 Quartz Combustion Tube (for two zone furnace equipped with the ability to switch
38、to pure oxygen carrier gas flow)D5762 12 (2017)36.8 Quartz Wool (optional), or other suitable absorbentmaterial that is stable and capable of withstanding temperaturesinside the furnace (see Note 2).NOTE 2Materials meeting the requirements in 6.8 are recommendedto be used in sample boats to provide
39、a more uniform injection of thesample into the boat by wicking any remainig drops of the sample fromthe tip of the syringe needle prior to introduction of the sample into thefurnace. Consult instrument manufacturer recommendations for furtherguidance.6.9 Silver Wool, as recommended by the instrument
40、 manu-facturer.6.10 Xylene. (WarningFlammable, health hazard.)6.11 Calibration Check Sample(s)portions of one or moreliquid petroleum or product standards of known nitrogencontent and not used in the generation of the calibration curve.A calibration check sample or samples shall be used to verifythe
41、 validity of the calibration curve as described in Section 10.6.12 Quality Control (QC) Sample(s)preferably portionsof one or more liquid petroleum materials that are stable andrepresentative of the samples of interest. These QC samplescan be used to verify that the testing process is in statistical
42、control as described in Section 10.7. Sampling7.1 Obtain a test sample in accordance with Practice D4057or D4177.(WarningSamples that are collected at tempera-tures below room temperature can undergo expansion atlaboratory temperatures and rupture the container. For suchsamples, do not fill the cont
43、ainer to the top. Leave sufficient airspace above the sample to allow room for expansion.)(WarningTo minimize loss of volatile components, whichcan be present in some test samples, do not uncover any longerthan necessary. Test samples should be analyzed as soon aspossible after taking from bulk supp
44、lies to prevent loss ofnitrogen or contamination due to exposure or contact withsample container.)7.2 If the test sample is not used immediately, then thor-oughly mix it in its container prior to taking a test specimen.Some test samples require heating in order to thoroughlyhomogenize.8. Preparation
45、 of Apparatus8.1 Assemble apparatus in accordance with the manufactur-ers instructions.8.2 Adjust the oxygen flow for the ozone generator inaccordance with the manufacturers instructions. Adjust thecombustion tube gas flows and the pyrolysis temperature to therecommended operating conditions using t
46、he following guide-lines for each furnace type. (WarningOzone is extremelytoxic. Make sure that appropriate steps are taken to preventdischarge of ozone within the laboratory work area.)8.2.1 For the single-zone furnace without the ability tochange to a pure oxygen carrier gas flow after the boat ha
47、s beenfully extended into the furnace, adjust the combustion tube gasflows to the following values: pyrolysis oxygen, 360 mLmin6 36 mLmin; inlet oxygen, 60 mLmin 6 6 mLmin; andinert carrier inlet, 155 mLmin 6 15 mLmin. Other gas flowsmay be used if it can be shown that precision and bias are notdegr
48、aded. Set the furnace temperature to 1100 C 6 25 C.Adjust the boat drive mechanism to obtain a drive rate of150 mmmin 6 10 mmmin. Refer to the manufacturersinstructions for descriptions of these settings.8.2.2 For the two-zone furnace without the ability to changeto a pure oxygen carrier gas flow af
49、ter the boat has been fullyextended into the furnace, adjust the combustion tube gas flowsto the following values: combustion oxygen, 165 mLmin616 mLmin; inlet inert carrier, 85 mLmin 6 9 mLmin; andboat inert carrier, 50 mLmin 6 5 mLmin. Other gas flowsmay be used if it can be shown that precision and bias are notdegraded. Set the inlet furnace temperature to 1050 C 625 C, and the outlet furnace temperature to 925 C 6 25 C.Adjust the boat drive mechanism to obtain a drive rate of150 mmmin 6 10 mmmin (boat speed number 4). Re
