1、Designation: D 2420 07An American National StandardStandard Test Method forHydrogen Sulfide in Liquefied Petroleum (LP) Gases (LeadAcetate Method)1This standard is issued under the fixed designation D 2420; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method2covers the detection of hydrogensulfide in liquefied petroleum
3、(LP) gases. The sensitivity of thetest is about 4 mg/m3(0.15 to 0.2 grain of hydrogen sulfide per100 ft3) of gas.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety
4、 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 prior to use.2. Referenced Documents2.1 ASTM Standards:3D 1835 Specification for Liquefied
5、 Petroleum (LP) Gases2.2 GPA Standard:4GPA 2140 Liquefied Petroleum Gas Specifications and TestMethods3. Summary of Test Method3.1 The vaporized LP gas is passed over moist lead acetatepaper under controlled conditions. Hydrogen sulfide reactswith lead acetate to form lead sulfide which produces aco
6、loration on the paper varying from yellow to black, depend-ing upon the amount of hydrogen sulfide present.4. Significance and Use4.1 Liquefied petroleum gases and their products of com-bustion must not be unduly corrosive to the materials withwhich they come in contact. The potential personnel expo
7、surehazards of H2S also make the detection and measurement ofhydrogen sulfide important, even in low concentrations. Inaddition, in some cases the odor of the gases must not beobjectionable. (See Specification D 1835 and GPA 2140.)5. Interferences5.1 Methyl mercaptan, if present, produces a transito
8、ryyellow stain on the lead acetate paper that will fade completelyin less than 5 min.5.2 Other sulfur compounds present in liquefied petroleumgas do not interfere with the test.6. Apparatus and Materials6.1 Apparatus for Detecting Hydrogen Sulfide in LiquefiedPetroleum Gas, as shown in Fig. 1 or com
9、mercially availableapparatus.6.2 Lead Acetate Test PaperCommercially available testpaper is satisfactory. Alternatively, the test paper may beprepared by dipping strips of smooth filter paper in 5 %aqueous lead acetate solution and removing the excess solutionwith a clean blotter. The strips of pape
10、r shall be approximately50 mm long and 10 mm wide and containa3mmhole near oneend so they will hang freely vertical in the test apparatus.6.3 Flow IndicatorA wet test meter or a rotameter, whichmeasures flow rates in the range of 2 to 3 L of gas/min.6.4 WaterDistilled.6.5 TubingHigh pressure connect
11、ing tubing to connect thetest apparatus to the sample collection point. Internally cleanstainless steel material is recommended, but other materialsthat safely contain the pressure, resist being cut or torn, andhave been tested to be inert relative to the stream being testedmay be utilized.1This tes
12、t method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.H0 on Liquefied Petroleum Gas.Current edition approved Feb. 15, 2007. Published March 2007. Originallyapproved in 1965. Last previous edition approved in 2
13、001 as D 242091(2001).2This test method is based on Edwards, J. D., and McBride, R. S., “LeadAcetateTest for Hydrogen Sulphide in Gas,” Technologic Papers T41, National Institute forStandards and Technology, Aug. 9, 1914.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
14、 ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from Gas Processors Association (GPA), 6526 E. 60th St., Tulsa, OK74145.1*A Summary of Changes section appears at the end of this
15、 standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Sampling7.1 (WarningBecause of the chemical activity and physi-cal adsorptive properties of hydrogen sulfide, it is highlydesirable to connect the test apparatus directly to
16、 the samplesource and perform the test in the field, rather than transferringsample into a sample cylinder for testing in the laboratory.Experience has demonstrated that the hydrogen sulfide concen-tration in liquefied petroleum gas is frequently depleted beforeanalysis, even when the sample is cont
17、ained in scrupulouslyclean, stainless steel sample cylinders. The exact oppositecondition, an increase in sulfide concentration, has been foundto occur when samples of liquefied petroleum gas containingno hydrogen sulfide are transferred into sample cylinders thathave not been properly cleaned and w
18、hich have been in usewith samples containing hydrogen sulfide. This demonstratesthat data obtained on samples tested for hydrogen sulfide in thelaboratory can be unreliable.)8. Procedure8.1 Connect the test apparatus to the sample source by useof a minimum length of clean stainless steel tubing or o
19、thermaterial that safely contains the pressure, resists being cut ortorn, and has been tested to be inert relative to the stream beingtested.8.2 Flush the line and apparatus for about 1 min.8.3 Fill the water reservoir with warm water (50 to 70C).8.4 By use of the needle valve, adjust the rate of ga
20、s flow to2.3 6 0.2 L/min.8.5 Immediately, place a single strip of distilled water-moistened lead acetate paper on the hook in the test cylinder sothat the paper is held midway between the watchglass and thebottom of the upper stopper.8.6 Expose the moist paper for exactly 2 min to the gas flowof 2.3
21、 6 0.2 L/min. Remove the test paper and proceed asdescribed in Section 9.9. Report9.1 Compare the exposed test paper with a moist test paperthat has not been exposed.9.1.1 In the absence of distinct coloration, report hydrogensulfide as “negative” (“pass”).9.1.2 If there is a distinct coloration, wa
22、it 5 min beforeinterpreting the test results. If, after 5 min, the paper has nodistinct coloration, rate the sample as “negative” (“pass”). Ifthe paper does have a distinct coloration after 5 min, rate thesample as “positive” (“fail”).NOTE 1The presence of methyl mercaptan in liquefied petroleum gas
23、gives a distinct yellow stain to the test paper which, however, fadescompletely in less than 5 min.NOTE 2 Concentrations of H2S in LPG of 4 mg/m3and higher willgive a positive result.9.2 Report the result, with reference to this test method, aseither “negative” (“pass”) or “positive” (“fail”).10. Pr
24、ecision and Bias10.1 In the case of passfail data or results from otherqualitative tests no generally accepted method for determiningprecision or bias is currently available.FIG. 1 Apparatus for Detecting Hydrogen Sulfide in Liquefied Petroleum GasD242007210.2 BiasThe procedure in Test Method D 2420
25、 for mea-suring hydrogen sulfide has no bias because the value ofhydrogen sulfide is defined only in terms of this test method.11. Keywords11.1 hydrogen sulfide; liquefied petroleum (LP) gasesSUMMARY OF CHANGESSubcommittee D02.H0 has identified the location of selected changes to this standard since
26、 the last issue(D 242091(2001) that may impact the use of this standard.(1) Revised 1.1, 3.1, 4.1, 6.4, 6.5, 7.1, 8.1.(2) Added Section 5, Note 1, Note 2, and 9.2.(3) Reorganized Sections 8 and 9.ASTM International takes no position respecting the validity of any patent rights asserted in connection
27、 with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible t
28、echnical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful conside
29、ration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr
30、 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D2420073
