1、Designation: D7773 12Standard Test Method forDetermination of Volatile Inorganic Acids (HCl, HBr, andHNO3) Using Filter Sampling and Suppressed IonChromatography1This standard is issued under the fixed designation D7773; the number immediately following the designation indicates the year oforiginal
2、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 test method is intended for use in the determinationof the time
3、-weighted average mass concentration of hydrogenchloride gas and hydrochloric acid mist, hydrogen bromidevapor and hydrobromic acid mist, and nitric acid vapor andmist in workplace air. The samples are collected on analkali-impregnated quartz fiber filter and analyzed by ionchromatography. The metho
4、d is also appropriate for measuringshort term exposures.1.2 This test method assumes that air samples are collectedusing appropriate and applicableASTM International standardsfor sampling of workplace air.1.3 The procedure is targeted for occupational and environ-mental hygiene monitoring purposes.1
5、.4 No detailed operating instructions are provided becauseof differences among various makes and models of suitableinstruments. Instead, the analyst shall follow the instructionsprovided by the manufacturer of the particular instrument. Thisstandard does not address comparative accuracy of different
6、devices or the precision between instruments of the same makeand model.1.5 The values stated in SI units are to be regarded as thestandard.1.6 The practice contains notes, which are explanatory andnot part of mandatory requirements of the standard.1.7 This standard does not purport to address all of
7、 thesafety 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:2D882 Test Method for Ten
8、sile Properties of Thin PlasticSheetingD1193 Specification for Reagent WaterD4840 Guide for Sample Chain-of-Custody ProceduresD5337 Practice for Flow Rate Adjustment of PersonalSampling PumpsD7035 Test Method for Determination of Metals and Met-alloids in Airborne Particulate Matter by InductivelyCo
9、upled Plasma Atomic Emission Spectrometry (ICP-AES)E1370 Guide for Air Sampling Strategies for Worker andWorkplace Protection2.2 ISO and European Standards:ISO 648 Laboratory glasswareOne mark pipettes3ISO 7708 Air qualityParticle size fraction definitions forhealth-related sampling3ISO 1042 Laborat
10、ory glasswareOne-mark volumetricflasks3EN 482 Workplace atmospheresGeneral requirements forthe performance of procedures for the measurement ofchemical agents4EN 1076 Workplace atmosphereProcedures for measur-ing gases and vapours using pumped samplersRequirements and test methods43. Summary of Test
11、 Method3.1 Aknown volume of air is drawn through a pre-filter andan alkali-impregnated quartz fiber filter, mounted in an inhal-able sampler, to collect HCl, HBr and HNO3. The acids arecollected on the impregnated quartz fiber filter, while particu-late salts of the acids are trapped on the pre-filt
12、er.3.2 The acids collected on the sampling filter are extractedwith water or eluent to solubilize the analytes of interest.3.3 Aliquots of the sample solution are subjected to ionchromatography in order to separate the extracted chloride,nitrate or bromide from other anions. Following this separa-ti
13、on, the anions are measured using a conductivity or UV-vis1This 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 Jan. 1, 2012. Published February 2012. DOI:10.1520/D7773-
14、12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANS
15、I), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from European Committee for Standardization (CEN), AvenueMarnix 17, B-1000, Brussels, Belgium, http:/www.cen.eu.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
16、States.detector and analytical results are obtained by plotting themeasured conductivity or absorbance as a function of concen-tration.3.4 The results can be used for assessment of occupationalexposure to HCl, HBr and HNO3in air.4. Significance and Use4.1 Exposure to inorganic acids in workplace air
17、 can causeirritations of the skin, eyes and respiratory tract, and exposurelimits for hydrochloric acid, hydrobromic acid and nitric acidin air have been established to reduce exposure risks topotentially affected workers (1).5Sampling and analyticalmethods for volatile inorganic acids are needed fo
18、r exposureassessment and risk reduction purposes.5. Apparatus5.1 Chlorides and nitrates are found ubiquitously in theenvironment and the presence of chloride and nitrate inreagents can lead to high blank values. It is therefore necessaryto check the blank values of all chemicals and labware beforeus
19、e.5.2 Sampling Equipment:5.2.1 Air samplers, designed to collect the inhalable fractionof airborne particles, as defined in ISO 7708. Suitable formounting a pre-filter (5.2.2) and sampling filter (5.2.3) sepa-rated by a spacer (5.2.4), manufactured from a material thatdoes not react with acids, for
20、collecting personal air samples asdescribed in Test Method D7035.NOTE 1The sampling method has only been tested at flow rates up to2 L/min so the inhalable samplers used should have a design flow rate of2 L/min or less.NOTE 2If samplers have an internal filter cassette, this too has to bemanufacture
21、d from a material that does not react with acids.NOTE 3Materials which do not react with acids, from which samplersand internal filter cassettes can be manufactured, include polytetrafluoro-ethylene (PTFE) and other fluorinated polymers, polyvinyl chloride(PVC), polyethylene, polypropylene and polyc
22、arbonate.5.2.2 Filters, of a diameter suitable for use with the sam-plers:5.2.2.1 Quartz Fiber Filters,5.2.2.2 Membrane Filters, PVC, 5-m pore size or below,and5.2.2.3 Membrane Filters, PTFE, 5-m pore size or below.5.2.3 Impregnated Filters, suitable for sampling of acidgases, for example, 25-mm dia
23、meter quartz fiber filters impreg-nated with 200 L of 265 g/L sodium carbonate solution (see6.7.1) or 37-mm diameter quartz fiber filters impregnated with500 L of 106 g/L sodium carbonate solution (see 6.7.2).5.2.4 Spacer, of a diameter suitable for use with the sam-plers, for separating the prefilt
24、ers and impregnated quartz fiberfilters, for example, polypropylene sleeves or PTFE-coatedscreens.5.3 Sampling Pumps, with an adjustable flow rate andcapable of maintaining the selected flow rate (between 1 L/minand 2 L/min for personal sampling pumps) to within 65%ofthe nominal value throughout the
25、 sampling period.5.4 Flow Meter, portable, capable of measuring the selectedvolumetric flow rate within 62 %, and calibrated against aprimary standard.5.5 Ancillary Equipment:5.5.1 Flexible Tubing, of a diameter suitable for making aleak-proof connection form the sampler to the sampling pump.5.5.2 B
26、elts or Harnesses, to which the sampling pump canbe conveniently fixed for personal sampling.5.6 Laboratory Equipment:5.6.1 Ion chromatograph having the following components:5.6.1.1 PumpCapable of delivering a constant flow withinthe range 0.1 mL/min to 5 mL/min at a pressure of 15 MPa to150 MPa.5.6
27、.1.2 Injection ValveA low dead volume, non-metallicvalve fitted with a sample loop having a volume of up to 500L, for injecting the sample solution into the eluent stream.5.6.1.3 Guard ColumnA column, placed before the sepa-rator column, to protect the latter from fouling by particles orstrongly ads
28、orbed organic constituents of the sample solution.5.6.1.4 Separator Column:1. Separator Column for Suppressed Ion Chromatography:Acolumn packed with high capacity pellicular anion exchangeresin, suitable for resolving nitrates chlorides or bromides fromother inorganic anions.2. Separator Column for
29、Non-suppressed Ion Chromatogra-phy:Acolumn packed with silica or organic polymers, suitablefor resolving chloride, bromide and nitrate from other inor-ganic anions.5.6.1.5 Suppressor ModuleA module to reduce the totalconductivity of the eluent suitable for use with the separatorcolumn.5.6.1.6 Detect
30、or:1. Conductivity Detector: Alow volume flow through with anon-metallic flow path conductivity detector.NOTE 4Aconductivity detector can be used with both suppressed andnon-suppressed ion chromatography2. Ultraviolet-visible (UV-vis) Detector: A low volume flowthrough UV-vis detector with a non-met
31、allic flow path detector.NOTE 5A UV-vis detector can be used with non-suppressed ionchromatography for inverse UV detection.5.6.1.7 Recorder, Integrator, or ComputerA device com-patible with detector output, capable of recording detectorresponse as a function of time for the purpose of measuringpeak
32、 height or area.5.6.1.8 Eluent ReservoirA container suitable for storing amanually prepared eluent solution.5.6.1.9 Eluent generation system, for producing an eluentsuitable for use with the selected separator column, as analternative to use of a manually prepared eluent (5).5.6.2 Ultrasonic bath, p
33、referably with a timer, suitable foruse in the ultrasonic extraction method for hydrogen chloride,nitric acid or hydrogen bromide.5.6.3 pH Meter5.7 Laboratory Supplies:NOTE 6It is normally preferable to use plastic labware rather thanglassware.5The boldface numbers in parentheses refer to a list of
34、references at the end ofthis standard.D7773 1225.7.1 One-mark Volumetric Flasks, of capacities between 20mL, 100 mL and 2 L.5.7.2 One-mark Pipets, complying with the requirements ofISO 648.5.7.3 Disposable Screw-cap Polyethylene Vessels,of15mLcapacity.5.7.4 Disposable Filters, PTFE, pore size 0.45 m
35、, for usein ion chromatography.5.7.5 Disposable 2-mL or 5-mL Syringes, with luer lockconnector, for use with disposable filters.5.7.6 Cation Exchange Resin Cartridges, suitable for re-moval of carbonate from test solutions to be analyzed byelectronically-suppressed ion chromatography.5.7.7 Autosampl
36、er Vials, of 1.5 mL-2 mL capacity.5.7.8 Pipet Tips, plastic, disposable, of assorted sizes, asneeded.5.7.9 Labware, plastic (beakers, flasks, graduated cylinders,etc.), of assorted sizes, as needed.5.7.10 Tweezers, manufactured from plastic or tipped withPTFE, for loading and unloading filters into
37、samplers.5.7.11 Personal Protective Wear, for example, respirators,masks, gloves, lab coats, safety eyewear, etc., as needed.5.7.12 Other General Laboratory Supplies, as needed.6. Reagents and Materials6.1 WaterUnless otherwise indicated, references to watershall be understood to mean reagent-grade,
38、 as defined by Type1 of Specification D1193 (ASTM Type 1 water: minimumresistance of 18 MV-cm or equivalent)6.2 Stock Standard Solution, 1000 mg/L anions (Cl-,Br-,NO3-) in water: Use a commercial standard solution with acertified concentration, for example, 1000 mg/L of chloride,bromide and nitrate
39、traceable to national standards. Observethe manufacturers expiration date or recommended shelf life.6.3 Working Standard Solution, 100 mg/L anions (Cl-,Br-,NO3-) in water: Accurately pipet appropriate volumes, forexample, 10 mL, of the Calibration stock solution I (6.7.2) intoa 100 mL one-mark volum
40、etric flask, dilute to the mark withwater, stopper and mix thoroughly. Prepare this solution freshmonthly.6.4 Sodium Carbonate (Na2CO3), anhydrous, purity99.9 % (m/m).6.5 Sodium Hydrogen Carbonate (NaHCO3), purity99.5 % (m/m).6.6 Sodium Carbonate Impregnation Solution:6.6.1 Sodium Carbonate Impregna
41、tion Solution for 25 mmFilters, 2.5 mol/L (265 g/L). Dissolve 26.5 g Na2CO3in water,quantitatively transfer the solution into a 100 mL one-markvolumetric flask, dilute to the mark with water, stopper and mixthoroughly.6.6.2 Sodium Carbonate Impregnation Solution for 37 mmFilters, 1 mol/L (106 g/L).
42、Dissolve 10.6 g Na2CO3in water.Quantitatively transfer the solution into a 100 mL one-markvolumetric flask, dilute to the mark with water, stopper and mixthoroughly.6.7 Reagents for Chemically Suppressed Ion Chromatogra-phy:NOTE 7The sodium carbonate/sodium hydrogen carbonate eluentprescribed below
43、is an example that can be used with separator columnsfor the determination of chloride, bromide and nitrate by chemicallysuppressed ion chromatography. The column manufacturers literaturewill give information on the composition of the eluent to be used with aspecific column type.6.7.1 Sodium Carbona
44、te/Sodium Hydrogen Carbonate Ex-traction and Eluent Stock Solution, 0.62 mol/L Na2CO3and0.069 mol/L NaHCO3. Dissolve 6.6 g of sodium carbonate and0.58 g sodium hydrogen carbonate in 25 mLof water and swirlto mix. Quantitatively transfer the solution to a 100 mLone-mark volumetric flask, dilute to th
45、e mark with water,stopper and mix thoroughly.6.7.2 Sodium Carbonate/Sodium Hydrogen Carbonate Ex-traction and Eluent Solution, 0.0031 mol/L Na2CO3and0.00035 mol/L NaHCO3. Transfer 10 mL of sodium carbonate/sodium hydrogen carbonate stock solution toa2Lone-markvolumetric flask, dilute to the mark wit
46、h water, stopper and mixthoroughly.6.7.3 Potassium Hydroxide Cartridge, suitable for use withthe eluent generation system, if appropriate.6.8 Reagents for Non-Suppressed Ion Chromatography:NOTE 8The phthalic acid and borate/gluconate solutions prescribedbelow are two examples of eluents used for the
47、 determination of HCl, HBrand HNO3using electronically suppressed ion chromatography. Thecolumn manufacturers literature will give information on the compositionof the eluent to be used with a specific column type.6.8.1 Phthalic Acid (C8H6O4), mass fraction 99.5 %.6.8.2 Acetonitrile (C2H3N), HPLC gr
48、ade.6.8.3 Methanol (CH3OH), HPLC grade.6.8.4 Lithium Hydroxide Monohydrate (LiOH3H2O), massfraction 99.5 %.6.8.5 Boric acid (H3BO4), mass fraction 99.8 %.6.8.6 Gluconic Acid Solution, mass fraction approximately50 % of D-gluconic acid (C6H12O7) in water.6.8.7 Glycerol (C3H8O3), mass fraction 99 %.6.
49、8.8 Phthalic Acid Extraction and Eluent Stock Solution,0.1 mol/L phthalic acid in 9:1 acetonitrile:methanol. Dissolve1.66 g of phthalic acid in 900 mL of acetonitrile and 100 mLof methanol in a suitable 1-L vessel and mix thoroughly.6.8.9 Lithium Hydroxide Solution, 1 mol/L lithium hydrox-ide. Dissolve 4.2 g of lithium hydroxide monohydrate in water.Quantitatively, transfer the solution into a 100 mL one-markvolumetric flask, dilute to the mark with water, stopper and mixthoroughly.6.8.10 Phthalic Acid Extraction and Eluent Solution, forexample, 0.005 m
