1、Designation: E1746 08E1746 17Standard Test Method forSampling and Analysis of Liquid Chlorine for GaseousImpurities1This standard is issued under the fixed designation E1746; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 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 sampling and analysis of liquid chlorine for the determination of oxygen (200 to 400 g/g)
3、, nitrogen(400 to 800 g/g), and carbon dioxide (800 to 1000 ppm) content at levels normally seen in liquid chlorine. Hydrogen and carbonmonoxide concentrations in liquid chlorine are typically at or below the detection limit of this test method.NOTE 1The minimum detection limit of hydrogen using a 1
4、 cm3 gas sample and argon carrier gas is 100 to 200 g/g.2 The detection limit for theother components is significantly lower.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 Review the current Material Safety Data Sheet
5、s (MSDS)(SDS) for detailed information concerning toxicity, first aidprocedures, and safety precautions.1.4 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 and
6、health practices and determine the applicability of regulatorylimitations prior to use. Specific hazards statements are given in Section 7.2. Referenced Documents2.1 Code of Federal Regulations:349 CFR 173, Code of Federal Regulations Title 49, Transportation: Shippers General Requirements for Shipm
7、ents andPackaging, including the following sections:173.304 Charging of Cylinders with Liquefied Compressed Gas173.314 Requirements for Compressed Gases in Tank Cars173.315 Compressed Gases in Cargo Tanks and Portable Tank Containers2.2 Other Document:Chlorine Institute Pamphlet No. 771 Sampling Liq
8、uid ChlorineChlorine Basics43. Summary of Test Method3.1 A sample of liquid chlorine is trapped in a sampling tube and vaporized into a steel bomb. The vaporized chlorine in thesteel bomb is introduced into a gas chromatograph by a gas sampling loop (1 cm3) using a ten-port gas sampling and switchin
9、gvalve. The separations are made on a PorapakPorapak5 Q column and on a 5A molecular sieve column whose lengths are suchthat the peaks do not overlap.3.2 Any component that co-elutes with the components of interest may interfere with this analysis.4. Significance and Use4.1 It is very difficult to e
10、xclude sample contamination by ambient air during the process of sampling. The levels of atmosphericcontamination caused by poor sampling methods are often equal to or larger than the levels of the gaseous impurities present in1 This test method is under the jurisdiction of ASTM Committee D16 on Aro
11、matic Hydrocarbons and Related Chemicals and is the direct responsibility of SubcommitteeD16.16 on Industrial and Specialty Product Standards.Current edition approved Dec. 15, 2008March 1, 2017. Published January 2009March 2017. Originally approved in 1995. Last previous edition approved in 20012008
12、as E1746 95 (2001)08. 1. DOI: 10.1520/E1746-08.10.1520/E1746-17.2 Thompson, B., Fundamentals of Gas Chromatography, Varian Instruments Division, Sunnyvale, CA, p. 73.3 Available from Standardization Documents Order Desk, Bldg. 4 Section D, DLA Document Services, Building 4/D, 700 Robbins Ave., Phila
13、delphia, PA 19111-5094,Attn: NPODS.http:/quicksearch.dla.mil.4 Available from The Chlorine Institute, Inc., 2001 L Street NW, Washington, DC 20036-4919.1300 Wilson Blvd., Suite 525, Arlington, VA 22209.5 Porapak is a trademark of Waters Associates, Inc.This document is not an ASTM standard and is in
14、tended 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 accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the cur
15、rent 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 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1the chlorine. This results in
16、markedly elevated levels of detected impurities. As specifications become tighter, it becomes moreimportant to measure the gaseous impurity levels in liquid chlorine correctly.4.2 Additional problems are experienced in the sampling of liquefied gases for the gaseous impurities. The gaseous impuritie
17、sreach an equilibrium between the liquid phase and vapor phase in a sample bomb. The quantity of gases measured in any particularsample containing both liquid and vapor will be a function of the amount of vapor space in the sample bomb. This test methodavoids the presence of liquid in the sample bom
18、b.5. Apparatus5.1 Gas ChromatographShimadzu GC-8AITequipped as shown in Fig. 1, or equivalent, equipped with a thermal conductivitydetector.5.2 Recorder, 1 mV, 0.5 s full-scale response.5.3 Valve Sequencer and Actuator, for switching valve control.5.4 Switching Valves.5.4.1 Ten-Port Switching and Sa
19、mpling Valve (stainless steel is acceptable).5.4.2 Four-Port Switching Valve (stainless steel is acceptable).FIG. 1 Chlorine Impurity Analysis System Flow DiagramE1746 1725.5 Chromatographic Columns, 3.2-mm outside diameter, 316 stainless, as follows:5.5.1 2 m of 80/100 mesh PorapakPorapak N,65.5.2
20、0.8 m of 80/100 mesh ShimaliteShimalite Q,75.5.3 1 m of 80/100 mesh ShimaliteShimalite Q,75.5.4 0.8 m of 80/100 mesh ShimaliteShimalite Q,75.5.5 3 m of 45/60 mesh molecular sieve 5A,5.5.6 2 m of 80/100 mesh PorapakPorapak Q,65.5.7 2 m of 80/100 mesh PorapakPorapak N,6 and5.5.8 1 m of 45/60 mesh mole
21、cular sieve 5A.5.6 Tantalum Tubing, 1.6-mm outside diameter, 0.57-mm inside diameter.NOTE 2Nickel tubing may be substituted for tantalum.5.7 MonelMonel Sampling Tube, 9.5 by 140-mm long (volume 5.4 cm3).85.8 Electronic Integrator, or computer integration package.5.9 TFE-Fluorocarbon Lined Flex Tubin
22、g, 6.35 mm.5.10 TFE-Fluorocarbon Tubing, 6.35 mm by 3.05 m.5.11 CajonCajon VCR Fitting. 95.12 Two-Valves, 9.5 mm, Monel.Monel.85.13 Four-Valves, 6.35-mm tubing to 6.35-mm pipe, Monel.Monel.85.14 HokeHoke10 Sample Cylinder, 1000 cm3, Monel,8 nickel, tantalum, or stainless steel.5.15 Pressure Gage, 91
23、 kg, Monel.Monel.85.16 Four-Pipe Tee, 6.35 mm, Monel.Monel.85.17 Vacuum Source, suitable for chlorine disposal.6. Reagents6.1 Gas Standard, 500 g/g H2, 400 g/g O2, 800 g/g N2, 50 g/g CO, and 1000 g/g CO2 in argon.116.2 Argon Carrier Gas, chromatographic grade.7. Hazards7.1 Safety Precautions:7.1.1 C
24、hlorine is a corrosive and toxic material. A well-ventilated fume hood should be used to house all sample handling andto vent the test equipment when this product is analyzed in the laboratory.7.1.2 The analysis should be attempted only by individuals who are thoroughly familiar with the handling of
25、 chlorine, and evenan experienced person should not work alone. The operator must be provided with adequate eye protection and respirator. Splashesof liquid chlorine destroy clothing and will produce irritations and burns if such clothing is next to the skin.7.1.3 Do not allow the sample cylinder to
26、 become liquid full if liquid samples are to be taken in cylinders. In accordance with49 CFR 173.304, 173.314, and 173.315, a good rule is that the weight of the chlorine in the cylinder should not be more than 125 %of the weight of the water that the cylinder could contain.7.1.4 When sampling and w
27、orking with chlorine out of doors, people downwind from such an operation should be warned ofthe possible release of chlorine vapors.7.1.5 In the event that chlorine is inhaled, first aid should be summoned immediately and oxygen administered without delay.7.1.6 Store pressurized samples where invol
28、untary release would not cause excessive risk to people or property.7.1.7 It is recommended that means be available for the disposal of excess chlorine in an environmentally safe and acceptablemanner. A chlorine absorption system should be provided if the chlorine cannot be disposed of in a chlorine
29、 consuming process.When the analysis and sampling regimen requires an initial purging of chlorine from a container, the purged chlorine should behandled similarly. Purging to the atmosphere should be avoided.6 PorapakPorapak materials, or their equivalent, have been found satisfactory for this purpo
30、se.7 Shimalite materials, Shimalite, a trademark of Shimadzu Seisakusho Ltd., Japan, materials or their equivalent, have been found satisfactory for this purpose.8 Monel material, Monel, a trademark of Special Metals Corporation, material or its equivalent, has been found satisfactory for this purpo
31、se.9 Cajon fittings, Cajon, a trademark of Swagelok Company, fittings or their equivalent, have been found satisfactory for this purpose.10 Hoke Hoke, registered trademark of Hoke Inc., sample cylinders, or their equivalent, have been found satisfactory for this purpose.11 This reagent is used for c
32、alibration only.E1746 1738. Sampling8.1 Assemble the sampling apparatus as shown in Fig. 2, and purge the system with argon before going into the field to sample.8.2 Attach the sampling apparatus to the source of liquid chlorine to be sampled and the vacuum source.8.3 Open all valves on the sample a
33、pparatus except Valve No. 5 on the sample bomb end opposite the gage. Evacuate the systemusing the vacuum source.8.4 Close all of the valves in the system. Leave the apparatus attached to the vacuum system with the vacuum system on.8.5 Open the valve on the source of liquid chlorine.8.6 The followin
34、g describes the cleanout of the sampling tube made from the 9.5-mm MonelMonel8 tubing:8.6.1 Open Valve No. 3 from the sample bomb to the vacuum source and leave open.8.6.2 Open Valve No. 1 on the end of the sampling tube connected to the chlorine source for approximately 15 s.8.6.3 Close Valve No. 1
35、.8.6.4 Slowly open Valve No. 2 on the end of the sampling tube that is connected to the sample bomb, and vent the chlorinetrapped in the sampling tube into the vacuum system.8.6.5 Close Valve No. 2.8.7 Repeat 8.6 8.10 two more times so that the sampling tube has been filled and emptied a total of th
36、ree times.8.8 Close Valve No. 3 between the vacuum source and sample bomb, and open Valve No. 4 on the gage end of the sample bomb.8.9 Open Valve No. 1 on the end of the sampling tube connected to the chlorine source for approximately 15 s.8.10 Close Valve No. 1 and open Valve No. 2 slowly.8.11 Slow
37、ly open Valve No. 3 between the sample cylinder and the vacuum source.8.12 Close Valves No. 2 and No. 3.8.13 Repeat 8.11 8.15 three more times. On the fourth time purging the sample cylinder, do not open Valve No. 3, whichconnects the sample bomb connections to the vacuum source, but close Valve No.
38、 4 on the gage end of the sample bomb.FIG. 2 Chlorine Sampling ApparatusE1746 1748.14 Close the valve on the source of the liquid chlorine.8.15 Evacuate all lines that might contain liquid chlorine by opening all valves except those on the sample bomb and liquidchlorine source. Check the pressure on
39、 the sample bomb to ensure that it is below the vapor pressure of liquid chlorine at roomtemperature. This ensures that only vapor chlorine is present in the sample bomb.8.16 Disconnect the sample bomb from the sampling apparatus and the sampling apparatus from the source of the chlorine. Thepressur
40、e in the sample bomb should be below 54 kg to contain only vapor in the bomb.8.17 This chlorine sample is now ready for analysis by the following method.9. Preparation of Standards for Calibration9.1 Obtain a custom blend of 500 g/g H2, 400 g/g O2, 800 g/g N2, 50 g/g CO, and 1000 g/g CO2 by volume i
41、n argon froma supplier of custom gas standards.10. Column Preparation and Instrumental Parameters10.1 Remove trace components from the columns by heating them overnight at 175C with 20 cm3/min argon flowing throughthem. See Fig. 1 for the correct carrier flow path to clean the gas chromatography (GC
42、) columns.10.2 Temperatures:Column: 75CInjection port: 110CDetector: 110C10.3 Argon Carrier Gas Flows:Reference: 20 cm3/minColumn: 20 cm3/min10.3.1 Activate the ten-port valve (the dashed line flow path), and check the flow at the thermal conductivity detector (TCD)1 vent. Adjust the flow to 20 cm3/
43、min with the carrier gas No. 1 pressure regulator.10.3.2 Deactivate the ten-port valve (the solid line flow path), and activate the four-port valve (the dashed line flow path). Checkthe flow at the TCD 1 vent and adjust to 20 cm3/min with the carrier gas No. 2 pressure regulator.10.3.3 Activate the
44、four-port valve (the dashed line flow path), and adjust the flow to 20 cm3/min at the TCD 1 vent with theauxiliary pressure regulator.10.3.4 At this point, check the flow at the end of the needle valve restrictor and before the “T” prior to the TCD 1 detector, andadjust with the restrictor needle va
45、lve to 20 cm3/min.10.4 Detector Current, 80 ma.10.5 Sample Size, cm3 gas loop.10.6 Valve Switching Time, see Note 4.10.7 Attenuation, as needed.NOTE 3Conditions are given for a Shimadzu GC-8AIT and are shown in Fig. 1. These conditions may vary for other types of instruments. Since thequality of pac
46、king material (especially molecular sieve) varies greatly, the lengths given for each of the columns in Fig. 1 are only approximate. Flowrates and column lengths are varied so as to balance the system to arrive at complete separation of the components and a stable baseline during valveswitching.NOTE
47、 4 The exact timing will depend on the specific resistances of the columns used, flow rates, and column efficiencies. Timing is established bycareful study of the system during setup.NOTE 5Fig. 3 shows a typical chromatogram that can be obtained with this system. Hydrogen and carbon monoxide concent
48、rations in liquid chlorineare typically at or below the detection limit of this test method. Although carbon monoxide is not shown in this chromatogram, it would have a retentiontime after nitrogen and before carbon dioxide.11. Calibration11.1 Determine the response of each component (O2, N2, CO, CO
49、2, and H2) by analyzing a 1 cm3 sample of the customlaboratory blend of these gases in argon, as outlined in Section 12.NOTE 6A 1 % commercial custom blend of the above components in argon was found to change composition after sitting several months. Althoughmore time consuming, the response factors can be determined by analyzing the individual pure gases. This approach also eliminates the shelf life problemassociated with commercially prepared standard blends.11.2 Determine the area response factors (V-s/g/g-cm3) for each comp
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