1、Designation: E 410 98 (Reapproved 2003)Standard Test Method forMoisture and Residue in Liquid Chlorine1This standard is issued under the fixed designation E 410; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of moistureand residue in liquid chlorine. Lower limits of detection of 10ppm (w/w)
3、based on a 150-mL sample are achievable.1.2 This test method describes operations and special appa-ratus for sampling liquid chlorine from cylinders. Samplingother commercial facilities such as tank cars, barges, andstorage tanks require special techniques of manipulation infilling sample cylinders
4、for testing. If conditions and facilitiesare favorable, the analysis apparatus may be connected directlyto these larger storage and transportation units and on-the-spottests may be completed.1.3 The analytical methods are empirical and are gravimet-ric. They are applicable to the determination of th
5、e residue andmoisture content of commercial grades of liquid chlorine(condensed gaseous product).1.4 Residue is defined as being those substances whichremain in the sample flask after sample volatilization under theconditions of the test. Moisture is defined as the volatilesubstances evolved during
6、volatilization and purging of thesample-residue flask and absorbed on the desiccant containedin the absorption tubes under the conditions of the test. Someof the volatile chlorinated hydrocarbons may also be evolvedfrom the sample residue flask during purge and absorbed, thuscontributing to the appa
7、rent moisture analysis value.1.5 This test method may be used for determining themoisture content only of gaseous chlorine if suitable andappropriate modifications are made for sample measurementand calculation.1.6 Review the current material safety data sheet (MSDS)for detailed information concerni
8、ng toxicity, first aid proce-dures, and safety precautions.1.7 The values stated in inch-pound units are to be regardedas the standard. The metric equivalents of inch-pound unitsmay be approximate.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its us
9、e. 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 prior to use. Specific hazardsstatements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:E 180 Practice for Determ
10、ining the Precision of ASTMMethods for Analysis and Testing of Industrial Chemicals22.2 Federal Standards:349 CFR 173 Code of Federal Regulations Title 49 Trans-portation; Shippers General Requirements for Shipmentsand Packagings, including Sections:173.304 Charging of Cylinders with Liquified Com-p
11、ressed Gas173.314 Requirements for Compressed Gases in TankCars173.315 Compressed Gases in Cargo Tanks and PortableTank Containers3. Summary of Test Method3.1 A common liquid sample of chlorine is recommended toprovide the best results when determining both residue andmoisture simultaneously.3.2 Liq
12、uid product sample is transferred from the samecylinder into a precalibrated, 250-mL sample-residue flask andpermitted to volatilize completely under prevailing environ-mental conditions. The volatilized product (chlorine gas) ispassed through anhydrous magnesium perchlorate desiccantfor absorption
13、of moisture. It is recommended that the exhaustgas be discharged into a caustic scrubber containing anappropriate amount of 20 % caustic solution to neutralize allthe chlorine. This reaction is exothermic and care should betaken to avoid excess heating by choosing a sufficienty largevolume of causti
14、c solution to serve as a heat sink.3.3 After complete volatilization of the sample from theflask, residual chlorine and moisture are expelled from anyresidue by purging with dry air through the absorption systemwhere moisture is recovered and determined gravimetrically.3.4 Residue remaining in the f
15、lask is determined by carefulanalytical weighing, the weight gain calculated as residue1This 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 approved Apr. 10, 2
16、003. Published May 2003. Originallyapproved in 1970. Last previous edition approved in 1998 as E 410 98.2Annual Book of ASTM Standards, Vol 15.05.3Available from Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO
17、 Box C700, West Conshohocken, PA 19428-2959, United States.content of the sample. Moisture is computed from the sum ofthe gain in weight of the two absorption tubes containing thedesiccant. Any gain in weight of the second absorber tubeshould be nominal with respect to that of the first tube in thes
18、eries.3.5 The moisture content of a chlorine gas stream isdetermined gravimetrically as above, by passing a meteredsample through the moisture absorption system only.4. Significance and Use4.1 This test method provides for the determination ofmoisture and residue in liquid chlorine. The concentratio
19、nlevels of these impurities are important factors in manycommercial uses of liquid chlorine.5. Apparatus5.1 The arrangement and assembly of apparatus for collec-tion and measurement of the analytical sample and volatiliza-tion is shown in Fig. 1.5.2 Sample-Residue Flask (H), Erlenmeyer-type, 250-mLc
20、apacity, equipped with a 35/20 JSground-ball joint.4Apermanent calibration mark shall be inscribed on the flask atthe 150-mL volume level for sample measurement.5.3 Adapter (G), equipped with a 35/20 JSground-socketjoint attached and sealed as shown in Fig. 1. In addition,appropriate 12/5 JSjoints s
21、hall be sealed to the adapter. A balljoint, sealed and closed off at the end, shall be provided forattachment to the inlet tube after collection of liquid sample inthe sample-residue flask. This shall be held in position with anappropriate clamp during volatilization, then removed andreplaced with a
22、ppropriate connections from the metered dry-airsupply at the time of aeration and purge of the sample-residueflask.5.4 A second assembly consisting of a sample-residue flaskand adapter shall be used to facilitate collection and disposal ofsample purge from the cylinder sample line prior to withdrawa
23、lof the analytical sample for test.5.5 RegulatorAn appropriate needle valve type shall beattached to the cylinder outlet to control and regulate the flowof liquid chlorine from the sample cylinder. Connection (F )between the outlet from this valve and the adapter (G) shall beby a short length of app
24、ropriately sized TFE-fluorocarbontubing equipped with a 12/5 JSground-ball joint.5.6 Rubber Tubing, length and size sufficient to exhaustchlorine vapors to the caustic soda absorber or hood systemduring sample collection and volatilization. A ground-glass12/5 JSsocket joint shall be fitted to one en
25、d of the rubbertubing to make appropriate connection to the adapter duringsample collection and transferred to the exhaust connectionfrom the second moisture absorption U-tube for gas dischargeto disposal during volatilization of the sample.5.7 Watch Glass, small size, used to close the sample-resid
26、ue flask during analytical weighing before and aftersample volatilization to prevent loss of residue or absorption ofmoisture from the atmosphere.5.8 Moisture Absorption Tubes (I) (Fig. 1)SchwartzU-tube design, 100 mm length top of arms to center, modifiedand equipped with ground-glass 12/5 JSsocket
27、 and ball jointssealed to the inlets and outlets. Two such absorber tubes shallbe connected in a series arrangement.5.9 Flow Meter, capable of metering air at 4.5 L/min andequipped with appropriate ground glass connection.4The recommended sample-residue flask, equipped with a 35/20 JSground-balljoin
28、t and the adapter equipped with a 35/20 JSground-socket joint and associated12/5 JSground joints shown in Fig. 1, will in all likelihood require fabrication by aglass blower. Alternatively, stock apparatus from Ace Glass Company, Inc.,Vineland, NJ, modified slightly and possessing reversed ground ne
29、ck and adapterjoints, has been found satisfactory. Sample-residue flask: Ace stock No. 6975.Adapter: Ace stock No. 5196, modified by reversing the 90 bend of the top inlettube and attaching 12/5 JSground joints.FIG. 1 Apparatus for Collection and Volatilization of Liquid ChlorineE 410 98 (2003)25.10
30、 Caustic Scrubber, for chlorine disposal.6. Reagents6.1 Purity of ReagentsUnless otherwise indicated, it isintended that all reagents should conform to the specificationsof the Committee on Analytical Reagents of the AmericanChemical Society, where such specifications are available.56.2 Pulverized D
31、ry Ice and a Small Amount of Trichloroet-hylene, contained in a glass crystallizing dish (190 by 100mm), for use in cooling the sample-residue flask during samplepurge, collection and measurement.6.3 Granular Form of Anhydrous MagnesiumPerchlorateReagent Grade.6.4 Caustic Solution20 % by weight, sod
32、ium hydroxidein water. Dissolve 200 g of sodium hydroxide (NaOH) in waterand dilute to 1 L. Store in a tight polyethylene container.7. Hazards7.1 Chlorine is a corrosive and toxic material. A wellventilated fume hood should be used to house the test equip-ment when this product is analyzed in the la
33、boratory.7.2 The analysis should be attempted only 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 respirator.Splashes of liquid chlorine destroy clothing and if su
34、chclothing is next to the skin, will produce irritations and burns.7.3 When sampling and working with chlorine out of doors,people downwind from such operation should be warned of thepossible release of chlorine vapors.7.4 It is recommended that means should be available fordisposal of excess chlori
35、ne in an environmentally safe andacceptable manner. If chlorine cannot be disposed of in achlorine consuming process, a chlorine absorption systemshould be provided. When the analysis and sampling regimenrequires an initial purging of chlorine from a container, thepurged chlorine should be similarly
36、 handled. Purging to theatmosphere should be avoided.7.5 In the event chlorine is inhaled, first aid should besummoned immediately and oxygen administered withoutdelay.8. Sampling Tank Cars, Barges, Large Cylinders, andStorage Facilities8.1 Sampling from tank cars, barges, storage tanks, andlarge cy
37、linders present unique problems. Each facility, how-ever, must be capable of delivering liquid-sample (not gas) fortest.8.2 Since location of these larger facilities may not be at theimmediate site of analysis, sample collection in a suitablesecondary container is recommended to facilitate its safet
38、ransport to the laboratory for tests.8.3 It is recommended that samples be collected from thesefacilities in small-size sample cylinders with cylinders andvalves fabricated of tantalum or nickel and capable of beingnegotiated in the laboratory fume hood. Technical literatureavailable from producers
39、and distributors of liquid chlorineshould be consulted for instructions in filling small sizecylinders properly from bulk storage.8.4 Do not allow the sample cylinder to become liquid full.A good rule is that the weight of the chlorine in the cylindershould not be more that 125 % of the weight of th
40、e water thatthe cylinder could contain in accordance with 49 CFR 173.9. Preparation of Apparatus9.1 Thoroughly clean the absorption tubes, sample-residueflasks, and adapters free of grease and lubricants, particularly atthe ground surfaces of the joints. After thorough cleansing, drythe apparatus th
41、ermally in an oven at 105C. When cooled,charge the absorption tubes with desiccant.9.2 Charge each tube within about 20 mm of the top in eachleg with a granular form of anhydrous magnesium perchlorate,minimizing the use of dusty product. Place loosely packedglass wool on the surfaces of the desiccan
42、t in both legs of theabsorber tube to avoid carry-over of chemical dust duringsample volatilization and air purge operations. Place theunlubricated stoppers firmly in the ground necks of the tubesand adjust to the “off” position preparatory to conditioningwith chlorine gas, air purge, and weighing.9
43、.3 Connect the moisture absorption tubes in a series bymeans of appropriately sized spring clamps in an uprightoperating position supported on a ring stand. Attach the groundjoint and rubber tubing to the outlet of the second absorber forexhausting chlorine gas to the caustic scrubber.9.4 Attach a s
44、ource of chlorine gas to the inlet of the firstabsorber tube, open the ground stoppers on both tubes topermit the free flow of gas through them and purge for1hata rate of 2 to 3 bubbles of chlorine gas/s when the exhaust endof the rubber tube is held momentarily beneath the surface ofwater.9.5 After
45、 purging with chlorine (see Section 10), attach thedry air supply to the first absorber in the series and aerate forexactly 5 min at a rate of 4.5 L/min.9.6 After aeration, carefully close the ground stoppers,dismantle the tubes from the assembly, and condition in theenvironment of the balance for 1
46、0 min prior to analyticalweighing of each tube. After weighing, the tubes may bereassembled for the next analysis.9.7 Conditioning of the absorber tubes with chlorine isrequired after an initial fresh charge of desiccant only. Aerationis required following volatilization of the sample for each test.
47、If the second tube contains 25 % of the total weight gain, thetubes need to be refilled.10. Drying Tower and Aeration10.1 The arrangement and assembly of apparatus used inaerating the equipment after volatilization includes a dryingtower, flow meter capable of metering air at 4.5 L/min, andappropria
48、te JSground connection.10.2 Construct the drying tower for conditioning air used inaeration of sample residue flask and moisture absorption tubes5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notliste
49、d 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.E 410 98 (2003)3from laboratory materials. Construct the tower of glass tubing480 mm in length and 50 mm in outside diameter. Close theends of the tube with tight-fitting rubber stoppers, the bottomstopper having a hole that supports a short, bent connectingglass tube which supplies compressed air to the tower.10.3 The stopper at the top of the tube sh
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1