1、Designation: E2036 15Standard Test Method forNitrogen Trichloride in Liquid Chlorine by High PerformanceLiquid Chromatography (HPLC)1This standard is issued under the fixed designation E2036; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, 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 uses high performance liquid chroma-tography (HPLC) to determine nitrogen trichl
3、oride levels inliquid chlorine at the 0.1 to 600 g/g (ppm) range. Solventsamples from chlorine production facilities containing veryhigh concentrations of nitrogen trichloride may be analyzed bydilution with methanol.1.2 Review the current safety data sheet (SDS) for detailedinformation concerning t
4、oxicity, first aid procedures, and safetyprecautions.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsi
5、bility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardstatements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2E180 Practice for Determining the Precision o
6、f ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdrawn 2009)3E806 Test Method for Carbon Tetrachloride and Chloroformin Liquid Chlorine by Direct Injection (Gas Chromato-graphic Procedure)2.2 Federal Standards:4CFR 173 Title 49 Transportation; Shippers General Re-qu
7、irements for Shipments and Packaging, including Sec-tions:173.304 Charging of Cylinders with Liquefied Com-pressed Gas173.314 Requirements for Compressed Gases in TankCars173.315 Compressed Gases in Cargo Tanks and PortableTank Containers2.3 Other Document:5Chlorine Institute Pamphlet No. 152 Safe H
8、andling of Chlo-rine Containing Nitrogen Trichloride3. Summary of Test Method3.1 Weighed samples of chlorine are delivered into a cooledgraduated centrifuge tube. One mL of cooled HPLC eluent isadded before the chlorine is allowed to evaporate. After thechlorine has evaporated the remaining eluent i
9、s analyzeddirectly on the HPLC for nitrogen trichloride concentration.3.2 In-process solvent samples from chlorine productionfacility may be analyzed by dilution in methanol followed bydirect HPLC analysis of the diluted solution.4. Significance and Use4.1 This test method was developed for the dete
10、rmination ofnitrogen trichloride in samples of carbon tetrachloride liquidtaken from the compressor suction chiller bottoms of chlorineproduction plants and other places in the plants that may collectand concentrate nitrogen trichloride to levels that could ex-plode. The test method was then modifie
11、d to measure the lowerlevels of nitrogen trichloride observed in product liquid chlo-rine. This test method is sensitive enough to measure the levelsof nitrogen trichloride observed in the normal production ofliquid chlorine.4.2 This test method for nitrogen trichloride will require thedilution (100
12、:1) of highly concentrated in-process samples tobring them within the working range of the analysis.1This test method is under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicalsand is the direct responsibility of SubcommitteeE15.02 on Product Standards.Current edition approv
13、ed June 1, 2015. Published June 2015. Originallyapproved in 1999. Last previous edition approved in 2007 as E2036-07. DOI:10.1520/E2036-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
14、 information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from U.S. Government Publishing Office, 732 N. Capitol St., NW,Washington, DC 20401-0001, http:/www.gpo.gov5Available from The
15、Chlorine Institute (CI), 1300 Wilson Blvd., Ste. 525,Arlington, VA 22209, http:/www.chlorineinstitute.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Interferences5.1 This test method is selective for nitrogen trichloride. Atth
16、is time there is no known interference in the materials usedin this test method.5.2 Contact with any metal surfaces should be avoided dueto the corrosive nature of the sample.5.3 Nitrogen trichloride is decomposed by UV light, heat orstrong acid. The presence of metal ions will increase the rate ofd
17、ecomposition. Special care should be taken to avoid exposureof the samples to direct sunlight. Samples and standards shouldbe analyzed immediately upon preparation. Samples not im-mediately analyzed must be stored in dry ice until just beforeanalysis.6. Apparatus6.1 Ahigh performance liquid chromato
18、graph (HPLC) com-posed of the following:6.1.1 HPLC Pump, capable of 1 mL/min flow,6.1.2 HPLC UV Detector, capable of operating at 221 nmwith a 1-cm light path,6.1.3 HPLC Injection Valve, 20 L sample loop, allnonmetal, and6.1.4 HPLC Column, C18 reverse phase, 25 cm by 4.6 mm.6.2 Plastic Syringes. 1,
19、2, 5, 10, 20, and 60 mL.6.3 Nonmetallic Syringe Needles.6.4 Top Loader Balance, capable of 0.01 g resolution and 1kg capacity.6.5 TFE-fluorocarbon Tubing, 1.59 mm outside diameter.6.6 Stainless Steel Sample Cylinder, with a needle valve onone end.6.7 Graduated Centrifuge Tube, 15 mL.6.8 Reducing Tub
20、e Fitting, 6.35 mm to 1.59 mm tubing.7. Reagents7.1 Purity of ReagentsUnless otherwise indicated, it isintended that all reagents shall conform to the specifications ofthe Committee onAnalytical Reagents of theAmerican Chemi-cal Society, where such specifications are available.6Othergrades may be us
21、ed, provided it is first ascertained that thereagent is of sufficiently high purity to permit its use withoutlessening the accuracy of the determination.7.2 Water, HPLC grade.7.3 Methanol, HPLC grade.7.4 Sodium Acetate, reagent grade.7.5 Glacial Acetic Acid, reagent grade.7.6 Dry Ice.7.7 Ammonium Su
22、lfate, reagent grade.7.8 Chlorine, reagent grade.7.9 Helium.8. Hazards8.1 Safety and Health PrecautionsExposure to all solventsused in this test method should be avoided.8.2 Concentrations of nitrogen chloride over 2 % pose therisk of explosion and should be considered dangerous. Neverallow any solu
23、tions containing nitrogen chloride to evaporate,concentrating the nitrogen chloride in the remaining residue.The concentrations of nitrogen trichloride synthesized in thistest method are small and should not pose any significant riskof explosion. All of the solutions prepared in this test methodcan
24、be disposed of by flushing them down any laboratory sinkusing a reasonable amount of water.8.3 Chlorine is a corrosive and toxic material. A well-ventilated fume hood should be used to house all samplehandling and to vent the test equipment when this product isanalyzed in the laboratory.8.4 This ana
25、lysis should only be performed by persons whoare thoroughly familiar with the handling of chlorine, and evenan experienced person should not work alone. The operatormust be provided with adequate eye protection and a respirator.Splashes of liquid chlorine destroy clothing and, if suchclothing is nex
26、t to the skin, will produce irritations and burns.8.5 If liquid samples are to be taken in cylinders, do notallow the sample cylinder to become liquid full. Test MethodE806, 49 CFR 173.314, 173.315, and 173.304 advise that theweight of the chlorine in the cylinder should not be more than125 % of the
27、 weight of the water that the cylinder couldcontain.8.6 When sampling and working with chlorine out-of-doors,people downwind from such an operation should be warned ofthe possible release of chlorine vapors.8.7 In the event chlorine is inhaled, first aid should besummoned immediately and oxygen admi
28、nistered withoutdelay.8.8 Store pressurized samples where involuntary releasewould not cause excessive risk to people or property.8.9 It is recommended that means be available for disposalof excess chlorine in an environmentally safe and acceptablemanner. If chlorine cannot be disposed of in a chlor
29、ineconsuming process, a chlorine absorption system should beprovided. When the analysis and sampling regimen requires aninitial purging of chlorine from a container, the purged chlorineshould be similarly handled. Purging to the atmosphere shouldbe avoided.9. Typical Instrument Parameters9.1 Adjust
30、the chromatograph in accordance with the fol-lowing parameters and allow the instrument to equilibrate untila steady baseline is obtained:9.1.1 ColumnC18 reverse phase ODS (C18) 25 cm by 4.6mm, 10 m,6Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, D
31、C. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.E2036 1529.1.2 Elu
32、ent60 % by volume methanol, 40 % by volume0.1 mol/L (M) acetate buffer, pH 4.5, helium sparged,9.1.3 Flow Rate1 mL/min,9.1.4 Injection Volume20-l sample loop, and9.1.5 Detector WavelengthUV at 221 nm.10. Preparation of Buffer Solution10.1 Sodium Acetate Buffer Stock Solution (1 mol/L (M)Dissolve 136
33、 g sodium acetate (NaOOCCH33H2O) and 60g glacial acetic acid (HOOCCH3) in water and dilute to 1 L.10.2 Sodium Acetate Buffer (0.1 mol/L (M)Transfer 100mL of the stock buffer solution into a 1-L volumetric flask anddilute to volume with water.11. Preparation of Eluent11.1 Add 600 mLmethanol to 400 mL
34、0.1 M sodium acetatebuffer solution and mix well. Before use purge the solutionwith helium for 20 min to remove dissolved oxygen.12. Preparation of the Sample Cylinder12.1 Clamp the sample cylinder in a vertical position withthe needle valve in the downward position. Insert the 6.35 mmend of the red
35、ucing tube fitting into the needle valve and set the6.35 mm nut and ferrule of the fitting. Insert the 1.59 mmfluoropolymer tubing in the reducing tube fitting and tightenthe 1.59 mm nut and ferrule. See Fig. 1. It may be helpful to cuta 6.35 mm circle of fluoropolymer frit material and place it int
36、othe reducing fitting prior to assembly to prevent plugging of the1.59 mm tubing. Cut the length of the 1.59 mm tubing so thatonly 38.10 mm protrudes out of the fitting.13. Standardization of the HPLC13.1 Prepare a 1000-g/g (ppm) stock solution of ammo-nium sulfate in water. Make a series of standar
37、ds of ammoniumsulfate by serial dilution covering the range between 1 and 650g/g (ppm) nitrogen trichloride. Calculate the nitrogen trichlo-ride concentration of each standard from the ammonium sulfateconcentration by multiplying by the ratio of the molecularweights, as follows:2NCl3/NH4!2SO4# 5 2 3
38、120.5/132! 5 1.826 (1)13.2 Withdraw 0.5 mL of an ammonium sulfate standardinto a 1-mL plastic syringe and then pull the plunger back tothe 1-mL mark to fill the remainder of the syringe with air.13.3 Clamp a sample cylinder containing reagent chlorinevertically in a ring stand and attach a 152.4 mm
39、piece of 1.59mm outside diameter fluoropolymer tubing to the valve. Takea second 1-mL plastic syringe and pull the plunger back to the1-mL mark. Insert the 1.59 mm fluoropolymer tubing into thesecond syringe and gently purge chlorine through the syringefilling this second syringe with reagent chlori
40、ne gas. Removethe fluoropolymer tubing from the syringe and attach anonmetal needle to the luer tip.13.4 Holding the first syringe pointed upward, use thesecond syringe equipped with the nonmetal needle to bubblethe reagent chlorine gas through the ammonium sulfate stan-dard solution, converting the
41、 ammonium ions to nitrogentrichloride. Use of a 1-mL syringe should avoid overchlorina-tion. See Fig. 2.13.5 Use the entire 0.5 mL standard to flush the samplevalve and fill the sample loop. Immediately inject this standardinto the HPLC for analysis. The nitrogen trichloride peak willelute between 1
42、1 and 12 min in the chromatogram. See Fig. 3.13.6 Measure and record the peak height of the nitrogentrichloride peak in the analysis of each of the standardsolutions. Plot the peak heights of each standard versus theconcentrations of the nitrogen trichloride in each standardanalyzed.The slope and in
43、tercept of this line will be used in thecalculation of the sample analysis values. See Figs. 4 and 5.NOTE 1Standards over 200 g/g (ppm) require 2 mL of chlorine gasfor complete conversion of the ammonium ions to nitrogen trichloride. Ifthe calibration curve is extended beyond 650 g/g (ppm), more tha
44、n 2 mLof reagent chlorine gas may be needed to obtain complete conversion ofthe ammonium ions in the standards. Although the amount of chlorineused for the chlorination of the standards is extremely small whencompared to that of the sample, it is always a good idea to prepare the firststandard in an
45、y calibration curve without the addition of the ammoniumsulfate to serve as a reagent blank.NOTE 2Two calibrations, one completed in December 1995 and onecompleted in February 1996, were not significantly different. This wouldindicate considerable stability of the UV detector. Considering the easewi
46、th which this test method can be calibrated, a one-point check of thecalibration curve is recommended on a weekly basis to ensure that thesystem is working properly.14. Procedure for Liquid Chlorine14.1 Tare a metal sample cylinder equipped with a needlevalve and cool the cylinder in dry ice making
47、sure that theneedle valve is closed. Sample the liquid chlorine source usingmetal tubing pipe connections. Do not use fluoropolymer orother type of plastic tubing that could transmit UV light.Nitrogen trichloride is very rapidly decomposed in the pres-ence of UV light. Consult The Chlorine Institute
48、 Pamphlet No.152 for additional information.14.2 Re-weigh the sample cylinder to determine the weightof chlorine collected in the cylinder before the cylinder isallowed to warm. If the cylinder is more than 60 % full, drainsome of the liquid chlorine out of the bottom of the cylinderand reweigh unti
49、l the weight of the chlorine is within accept-able limits for that cylinder.NOTE 3For example, a 150-mLcylinder should not contain more than90 mL of chlorine at a density of 1.467 g/mL (that is, 132 g of chlorine).14.3 Attach a 38.10 mm piece of 1.59 mm TFE-fluorocarbon tubing and reducing fitting to the needle valve onthe chlorine cylinder, weigh, and record the sample cylinderweight to the nearest 0.1 g. Clamp the cylinder in a ring standwith the needle valve and fluoropolymer tubing pointed down.FIG. 1 Sample CylinderE2036 15314.4 Cool a 15-mL centrif
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