1、Designation: D5762 12 (Reapproved 2017)D5762 17Standard 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 ofori
2、ginal 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 Scope*1.1 This test method covers the determination of nitrogen i
3、n liquid hydrocarbons, 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 st
4、andard. No other units 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 safety, health, and healthenvironmental
5、practices and determine theapplicability of regulatory 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 Decisio
6、n 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:2D4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice
7、 for Automatic Sampling of Petroleum and Petroleum ProductsD4629 Test Method for Trace Nitrogen in Liquid Petroleum Hydrocarbons by Syringe/Inlet Oxidative Combustion andChemiluminescence DetectionD6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate A
8、nalytical Measure-ment System Performance3. Summary 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 conta
9、ctsozone and is converted to excited nitrogen dioxide (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 cat
10、alysts. They tend to be the most difficult class 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 co
11、ntainingadditives. This test method is intended 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
12、is recommended to add a small piece of quartz wool 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 July 1, 2017Dec. 1, 2017. P
13、ublished July 2017January 2018. Originally approved in 1995. Last previous edition approved in 20122017 asD5762 12.D5762 12 (2017). DOI: 10.1520/D5762-12R17.10.1520/D5762-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For A
14、nnual Book of ASTM Standardsvolume information, refer to 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
15、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 ASTM is to be considered the official document.*A Summary of Changes section appears at the end
16、of this standardCopyright ASTM International, 100 Barr Harbor 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 adv
17、ances and withdraws the sample boat into and out of the 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.
18、NOTE 1Detectors designed to maintain the chemiluminescence 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
19、accept the sample boat and tohave side arms for introduction 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
20、oxidation of the sample. Combustion tubes recommended for the two furnaces in 5.5.1 and 5.5.2 are describedin 5.3.1 and 5.3.2. Other configurations are acceptable if precision and bias are not degraded.5.3.1 Quartz combustion tube for use with the single-zone furnace is illustrated in Fig. 1.Awater-
21、jacket around the inlet sectioncan be used to cool the boat prior to sample injection.5.3.2 Quartz combustion tube for use with the two-zone furnace is illustrated in Fig. 2. Fig. 3 illustrates a combustion tube fora two-zone furnace that is equipped with the ability to switch to a pure oxygen carri
22、er gas flow after the boat has been fullyextended into the furnace (consult the instrument manual to determine if the instrument changes to a pure oxygen carrier gas flowafter the boat is inserted). The outlet end of the pyrolysis tube is constructed to hold a removable quartz insert tube. The remov
23、ablequartz insert tube is packed with an oxidation catalyst as recommended by the instrument manufacturer.5.4 Drier Tube, for the removal 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
24、perchlorate, Mg(ClO4)2, scrubber, a membrane dryingtube permeation drier, or a chilled dehumidifier assembly.5.5 Furnace, Electric, held at 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
25、a method for gas flow control, such as needle valves, flowrestrictors or mass flow controllers. Furnaces that are operated at temperatures 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
26、 with temperature controller capable of maintaining a stable furnace temperature of 1100 C 625 C.5.5.2 Two-zone tube furnace with temperature 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 th
27、e ability to change to a pure oxygencarrier gas flow after the boat is fully extended in to the furnace and temperature controllers capable 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 micr
28、olitre quantities.5.7 Ozone Generator, to supply ozone to the detector reaction cell.5.8 Recorder (Optional), for display of chemiluminescence detector signal.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended
29、 that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society whereFIG. 1 Quartz Combustion Tube (Single-Zone Furnace)D5762 172such specifications are available.3 Other grades may be used, provided it is first ascertained that the reag
30、ent 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 Oxidation Catalyst: Cupric Oxide Wire, CuO, or Platinum Catalyst, PtAl2O3, as recommended by the instr
31、umentmanufacturer.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, Mg(ClO4)2, for drying products of combustion (if permeation drier or chilled drier isnot used). (Warnin
32、gStrong 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 method.3 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washi
33、ngton, 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 NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.FIG. 2 Q
34、uartz Combustion Tube (Two-Zone Furnace)FIG. 3 Quartz Combustion Tube (for two zone furnace equipped with the ability to switch to pure oxygen carrier gas flow)D5762 1736.6.2 Volumetric PreparationAccurately weigh (to the nearest 0.1 mg) approximately 0.64 g of acridine into a tared 100 mLvolumetric
35、 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 litre. This stock can be further diluted to desired nitrogen concentrations. (WarningRemake standard solutions on a regular basis depending
36、upon frequency of use and age. Typically, standards have a useful life ofapproximately three months.)6.6.3 Gravimetric PreparationAccurately weigh (to the nearest 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
37、 with xylene. Calculate the nitrogen contentof the stock solution to the nearest milligram of nitrogen per kilogram. Convert the concentration to milligrams of nitrogen perlitre by multiplying by the density of xylene. This stock can be further diluted to desired nitrogen concentrations.(WarningRema
38、ke standard solutions on a regular basis depending upon frequency 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.
39、(WarningVigorously accelerates combustion.)6.8 Quartz Wool (optional), 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 m
40、ore uniform injection of the sampleinto the boat by wicking any remainigremaining drops of the sample from the tip of the syringe needle prior to introduction of the sample into the furnace.Consult instrument manufacturer recommendations for further guidance.6.9 Silver Wool, as recommended by the in
41、strument manufacturer.6.10 Xylene. (WarningFlammable, health hazard.)6.11 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
42、verify the validityof the calibration curve as described in Section 10.6.12 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
43、statistical controlas described in Section 10.7. Sampling7.1 Obtain a test 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
44、fillthe container to the top. Leave sufficient air space above the sample 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
45、 from bulk supplies to prevent loss of nitrogen or contamination due to exposure 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 homogeniz
46、e.8. Preparation of Apparatus8.1 Assemble apparatus in accordance with the 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 c
47、onditions using the following guidelines for eachfurnace type. (WarningOzone 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
48、after the boat has been fullyextended into the furnace, adjust the combustion 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 a
49、nd bias are not degraded. Set the furnace temperature to 1100 C 6 25 C. Adjust 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 furnace, 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 c
