1、Designation: D4856 11Standard Test Method forDetermination of Sulfuric Acid Mist in WorkplaceAtmospheres Collected on Mixed Cellulose Ester Filters (IonChromatographic Analysis)1This standard is issued under the fixed designation D4856; the number immediately following the designation indicates the
2、year oforiginal 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. Scope1.1 This ion chromatographic test method describes thede
3、termination of sulfuric acid mist in air samples collectedfrom workplace atmospheres on a mixed cellulose ester (MCE)filter.NOTE 1Other filter types such as quartz fiber, polytetrafluoroethylene(PTFE), and polyvinyl chloride (PVC) filters are also suitable.1.2 The lower detection limit of this test
4、method is 0.001mg/sample or 0.017 mg/m3of sulfuric acid (H2SO4) mist in 60L of air sampled at 1 L/min.1.3 This test method is subject to interference from solubleand partially soluble sulfate salts. Other sulfur-containingcompounds can be oxidized to sulfate and also interfere.1.4 The values stated
5、in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 No detailed instrument operating instructions are pro-vided because of differences among various makes and modelsof ion chromatography (IC) systems. Instead, the analyst shallfollow the instruct
6、ions provided by the manufacturer of theparticular instrument, analytical column, and suppressors used.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and h
7、ealth practices and determine the applica-bility of regulatory limitations prior to use. For specificprecautionary statements, see Section 9.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1914 Practice
8、 for Conversion Units and Factors Relatingto Sampling and Analysis of AtmospheresD4327 Test Method for Anions in Water by Suppressed IonChromatographyE200 Practice for Preparation, Standardization, and Storageof Standard and Reagent Solutions for Chemical Analysis2.2 ISO3and European Standards4:ISO
9、648 Laboratory glasswareOne Mark pipettesISO 7708 Air qualityParticle size fraction definitions forhealth-related samplingISO 1042 Laboratory glasswareOne-mark volumetricflasksEN 482 Workplace atmospheresGeneral requirements forthe performance of procedures for the measurement ofchemical agents.EN 1
10、540 Workplace atmospheresTerminologyEN 13890 Workplace atmospheresProcedures for mea-suring metals and metalloids in airborne particlesRequirements and test methods3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D1356 and EN 1540.3.2 Definitions of
11、 Terms Specific to This Standard:3.2.1 eluentionic mobile phase used to transport thesample through the exchange columns.3.2.2 resolutionability of a column to separate constitu-ents under specified test conditions.4. Summary of Test Method4.1 A known volume of air is drawn through mixed cellu-lose
12、ester membrane filter-mounted in an appropriate airsampler. Examples are, but not limited to: inhalable samplers,1This test method is under the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.04 on Workplace AirQuality.Current edition approved Se
13、pt. 15, 2011. Published September 2011. Originallyapproved in 1988. Last previous edition approved in 2004 as D4856 - 99 (2004).DOI: 10.1520/D4856-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
14、ards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from European Committee for Standardization (CEN), AvenueMarnix 17, B-100
15、0, Brussels, Belgium, http:/www.cen.eu.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.25-mm 3-piece, and 37-mm 3-piece cassettes supported by aback-up pad or screen.54.2 The sulfuric acid collected on the filter is desorbed withD119
16、3 Type 1 water. An aliquot of the desorbed samplesolution is injected into an ion chromatograph to determine thesulfate ion concentration.5. Significance and Use5.1 Sulfuric acid is used in the manufacture of fertilizer,explosives, dyestuffs, other acids, parchment paper, glue, leadacid batteries, t
17、extiles, etc., and in the pickling of metals.5.2 This test method has been found to be satisfactory in themeasurement of sulfuric acid for comparison with relevantoccupational exposure limits.6. Interferences6.1 Soluble or partially soluble sulfate salts, for example,sodium or calcium sulfate, will
18、be measured as sulfuric acid.Other sulfur-containing compounds can be oxidized to sulfateand also interfere.7. Apparatus7.1 Sampling Equipment:7.1.1 Air sampler designed to collect the appropriate aerosolsize fraction needed. Examples are: inhalable sampler, 3-piece37-mm or 25-mm filter cassette con
19、structed of styrene acrylo-nitrile to hold the filter that is supported by a cellulose pad.7.1.2 A MCE filter.NOTE 2This method may also be used with other appropriate filterssuch PTFE, Glass Fiber, PVC, and others.7.1.3 A personal sampling pump capable of maintaining therequired sampling rate throu
20、gh the sampler throughout thesampling period.7.2 Ion Chromatograph:7.2.1 Pump, capable of delivering a constant flow of 0.1 to5 mL of eluent per minute at a pressure of from 3.4 to 34 MPa(500 to 5000 psi).7.2.2 Injection Valve, a low dead volume, non-metallicvalve fitted with a sample loop having a
21、volume of up to 500l, for injecting the samples into the eluent stream. Anautosampler can be attached for automation.7.2.3 Guard Column, a column placed before the separatorcolumn to protect it from being fouled by particulate matter.7.2.4 Separator Column, a column packed with anion ex-change resin
22、 that is suitable for resolving the sulfate anion.7.2.5 Suppressor Module, a module to reduce the totalconductivity of the eluent, suitable for use with the separatorcolumn and capable of converting the eluent and separatedanions to their respective acid forms.7.2.6 Conductivity Detector, a low-volu
23、me, flow-through,temperature-compensated, electrical conductivity cell.7.2.7 Recorder, Integrator, or Computer, a device for thepurpose of measuring peak height or area, compatible with thedetector output, and capable of recording detector response asa function of time.7.2.8 Eluent Reservoir, a cont
24、ainer suitable for storing aprepared eluent solution.7.2.9 Eluent Generation System, for continuous productionof eluent, suitable for use with the selected separator column,as an alternative to using a manually-prepared eluent.7.2.10 Ultrasonic Bath, preferably with a timer, suitable foruse in the u
25、ltrasonic extraction.7.3 Laboratory Supplies:7.3.1 One-mark Volumetric Flasks, capacities between 10mL and 2000 mL.7.3.2 One-mark Pipets, complying with the requirements ofISO 648.7.3.3 Disposable Screw-cap Polyethylene Vessels, of 15-mLcapacity.7.3.4 Disposable Filters, polytetrafluorethylene (PTFE
26、),pore size 0.25 m, for use in ion chromatography.7.3.5 Disposable 2-mL or 5-mL Syringes, with Luer lockconnector, for use with disposable filters, or for sampleinjections without an autosampler.7.3.6 Autosampler Vials, suitable for the autosampler used.7.3.7 Pipet Tips, plastic, disposable, of asso
27、rted sizes, asneeded.7.3.8 Labware, preferably plastic (beakers, flasks, graduatedcylinders, etc.), of assorted sizes, as needed.7.3.9 Tweezers, manufactured from plastic or tipped withPTFE, for loading and unloading filters into samplers.8. Reagents8.1 Reagent-grade chemicals shall be used in all t
28、ests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, where suchspecifications are available. Other reagents may be usedprovided it can be demonstrated that they are of sufficientl
29、yhigh purity to permit the use without decreasing the accuracyof the determination.8.2 WaterUnless otherwise indicated, reference to watershall be understood to mean ultra-pure, Type I water asdescribed in Specification D1193.8.3 Stock Solutions1000 g/mL (mg/L) sulfate in water.Use a commercial stan
30、dard solution with a certified concen-tration traceable to national standards.NOTE 3The sodium carbonate/sodium bicarbonate eluent prescribedbelow is an example that can be used with separator column for thedetermination of sulfate by chemically suppressed ion chromatography.The manufacturers litera
31、ture will give information on the composition ofeluent to be used with a specific column.8.4 Sodium Carbonate/Sodium Bicarbonate Eluent0.0031 Na2CO3and 0.00035 M NaHCO3. Dissolve 0.657 g ofanhydrous Na2CO3and 0.059 g of NaHCO3in a 2000-mL(2-L) volumetric flask with water and dilute to mark.8.5 Eluen
32、t Generation CartridgePotassium hydroxide orpotassium carbonate cartridge for eluent generator, appropriatefor column and suppressor used.8.6 Suppressor Regenerant Solution (for use with suppres-sor columns)Many suppressors currently use electrolysis of5Precision (CVT= 0.082) was obtained (NIOSH Con
33、tract No. CDC-99-74-45)over a range of 0.561 2.577 mg/M3using mixed cellulose ester filters.D4856 112the eluent for chemical suppression. Refer to manufacturersliterature for the composition of the suppressor regenerationsolution.9. Precautions9.1 Safety PrecautionsExtreme care must be taken whenpre
34、paring solutions from concentrated sulfuric acid. The trans-fers should be performed in a fume hood with adequateventilation while wearing the proper safety equipment.9.2 Technical PrecautionsAll storage containers shouldbe plastic such as polyethylene (or polypropylene) to preventleaching of the an
35、alytes. All connections must be made withnon-metallic materials suitable for use with ion chromato-graphs.10. Sampling10.1 Attach the sampler containing the filter to a personalsampling pump using tubing of the appropriate size so as torender a leak-proof system and fasten it to the workers lapel.10
36、.2 Collect air samples at the appropriate flow rate for thesampler until a minimum of 60 L has been collected.10.3 Remove the filter from the sampler within one hour ofsampling and transfer to a screw cap, polyethylene (or poly-propylene) bottle.11. Calibration11.1 Determination of Retention Time Th
37、e retention timefor sulfate anion is determined by injecting a standard solutionand noting the time required for a peak to appear on thechromatogram.11.2 Preparation of Calibration SolutionsUsing the stockstandard solution and water, prepare at least five workingstandards using appropriate pipettes
38、and volumetric flasks.Standards shall encompass the range of sulfate concentrationsexpected for the samples, (for example, 1 to 100 g/L).11.3 Prepare an analytical curve for sulfate using peakheight or area versus concentration. A least-squares plot of thedata should be presented.11.4 At least one b
39、lank of each prepared solution shall beanalyzed.12. Procedures12.1 Pipet 10 mL of water into the sample bottle containingthe filter. Shake the sample bottle vigorously or sonicate it for15 minutes, and allow to stand until the sample solution comesto room temperature.12.2 Filter an aliquot of the sa
40、mple solution through adisposable filter (7.3.4) using a disposable syringe (7.3.5).12.3 Set up the IC system for the analysis of sulfate basedon manufacturers literature for the column, suppressor, andsystem used.12.4 Transfer a portion of the filtered sample solution to anautosampler vial, or a sy
41、ringe for manual injections, and injectan aliquot into the chromatograph (for example, 50 L for a4-mm column).NOTE 4Manual injections require 2 to 3 mL to ensure completeflushing of the injection loop.12.5 Determine the amount of sulfate in each sample bycomparing peak area or height to the response
42、 obtained fromthe calibration curve determined in 11.3. If sulfate is greaterthan the highest standard, dilute with water and rerun using theappropriate dilution factor.13. Calculation13.1 Calculate the concentration (mg/m3) of sulfuric acid inair as follows:mg/m3,H2SO45g/mLSO43 10 3 1.02Vair(1)wher
43、e:10 = millilitres of water added to filter,1.02 = conversion factor for H2SO4, from SO4Vair= litres of air sampled.14. Precision and Bias14.1 The single-operator and overall precision of this testmethod, within its designated range for seven operators inseven different laboratories with a 10-mL vol
44、ume, is expressedas follows:Theoretical, g Observed Standard Deviation, g6.00 1.1360.0 7.7120 17.514.2 Recoveries and bias of known amounts of sulfate inseven different laboratories using the same manufacturersinstrumentation and operation conditions are expressed asfollows:Theoretical,(g)Observed,(
45、g)Bias,(g)Bias,(%)StatisticallySignificant95 % Level6.00 5.07 .93 15.5 Yes60.0 49.1 10.9 18.2 Yes120 97.6 22.4 18.7 Yes15. Keywords15.1 air monitoring; ion chromatography; sampling andanalysis; sulfuric acid mist; workplace atmosphereD4856 113ASTM International takes no position respecting the valid
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47、ct to revision at any time by the responsible technical 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 Headquart
48、ers. Your comments will receive careful consideration 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
49、 is copyrighted by ASTM International, 100 Barr 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D4856 114
