ASTM D7773-19

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Designation: D7773 − 12 D7773 − 19
Standard Test Method for
Determination of Volatile Inorganic Acids (HCl, HBr, and
HNO ) Using Filter Sampling and Suppressed Ion
Chromatography
This standard is issued under the fixed designation D7773; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method is intended for use in the determination of the time-weighted average mass concentration of hydrogen
chloride gas and hydrochloric acid mist, hydrogen bromide vapor and hydrobromic acid mist, and nitric acid vapor and mist in
workplace air. The samples are collected on an alkali-impregnated quartz fiber filter and analyzed by ion chromatography. The This
test method is also appropriate for measuring short term exposures.
1.2 This test method assumes that air samples are collected using appropriate and applicable ASTM International standards for
sampling of workplace air.
1.3 The procedure is targeted for occupational and environmental hygiene monitoring purposes.
1.4 No detailed operating instructions are provided because of differences among various makes and models of suitable
instruments. Instead, the analyst shall follow the instructions provided by the manufacturer of the particular instrument. This
standard does not address comparative accuracy of different devices or the precision between instruments of the same make and
model.
1.5 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.
1.6 The practice This test method contains notes, which are explanatory and not part of mandatory requirements of the standard.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D882 Test Method for Tensile Properties of Thin Plastic Sheeting
D1193 Specification for Reagent Water
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
D4840 Guide for Sample Chain-of-Custody Procedures
D5337 Practice for Flow Rate Adjustment of Personal Sampling Pumps
D7035 Test Method for Determination of Metals and Metalloids in Airborne Particulate Matter by Inductively Coupled Plasma
Atomic Emission Spectrometry (ICP-AES)
E1370 Guide for Air Sampling Strategies for Worker and Workplace Protection
2.2 ISO and European Standards:
ISO 648ISO 648 Laboratory glassware—One mark pipettesGlassware — Single-Volume Pipettes
ISO 1042 Laboratory Glassware — One-Mark Volumetric Flasks
This test method is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.04 on Workplace Air Quality.
Current edition approved Jan. 1, 2012Oct. 1, 2019. Published February 2012October 2019. DOI:10.1520/D7773-12. Originally approved in 2012. Last previous edition
approved in 2012 as D7773 – 12. DOI:10.1520/D7773-19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7773 − 19
ISO 7708ISO 7708 Air quality—Particle size fraction definitions for health-related samplingQuality — Particle Size Fraction
Definitions for Health-Related Sampling
ISO 1042 Laboratory glassware—One-mark volumetric flasks
EN 482 ISO 20581 Workplace atmospheres—General requirements Air — General Requirements for the performancePerfor-
mance of proceduresProcedures for the measurementMeasurement of chemical agentsChemical Agents
EN 1076ISO 22065 Workplace atmosphere—Procedures for measuring gases and vapours using pumped samplers—
Requirements and test methodsAir — Gases and Vapours — Requirements for Evaluation of Measuring Procedures Using
Pumped Samplers
3. Terminology
3.1 Definitions—For definitions of terms used in this test method, refer to Terminology D1356.
4. Summary of Test Method
4.1 A known volume of air is drawn through a pre-filter and an alkali-impregnated quartz fiber filter, mounted in an inhalable
sampler, to collect HCl, HBr, and HNO . The acids are collected on the impregnated quartz fiber filter, while particulate salts of
the acids are trapped on the pre-filter.
4.2 The acids collected on the sampling filter are extracted with water or eluent to solubilize the analytes of interest.
4.3 Aliquots of the sample solution are subjected to ion chromatography in order to separate the extracted chloride, nitrate or
bromide from other anions. Following this separation, the anions are measured using a conductivity or UV-vis ultraviolet-visible
(UV-vis) detector and analytical results are obtained by plotting the measured conductivity or absorbance as a function of
concentration.
4.4 The results can be used for assessment of occupational exposure to HCl, HBr, and HNO in air.air (see Guide E1370).
5. Significance and Use
5.1 Exposure to inorganic acids in workplace air can cause irritations of the skin, eyes and respiratory tract, and exposure limits
for hydrochloric acid, hydrobromic acid and nitric acid in air have been established to reduce exposure risks to potentially affected
workers (1). Sampling and analytical methods for volatile inorganic acids are needed for exposure assessment and risk reduction
purposes.
6. Apparatus
6.1 Chlorides and nitrates are found ubiquitously in the environment and the presence of chloride and nitrate in reagents can
lead to high blank values. It is therefore necessary to check the blank values of all chemicals chemicals, sampling equipment (such
as filters), and labware before use.
6.2 Sampling Equipment:
6.2.1 Air samplers, designed to collect the inhalable fraction of airborne particles, as defined in ISO 7708. Suitable for mounting
a pre-filter (5.2.26.2.2) and sampling filter (5.2.36.2.3) separated by a spacer (5.2.46.2.4), manufactured from a material that does
not react with acids, for collecting personal air samples as described in Test Method D7035.
NOTE 1—The sampling method has only been tested at flow rates up to 2 L/min so the inhalable samplers used should have a design flow rate of 2
L/min or less.
NOTE 2—If samplers have an internal filter cassette, this too has to be manufactured from a material that does not react with acids.
NOTE 3—Materials which do not react with acids, from which samplers and internal filter cassettes can be manufactured, include polytetrafluoroeth-
ylene (PTFE) and other fluorinated polymers, polyvinyl chloride (PVC), polyethylene, polypropylene, and polycarbonate.
6.2.2 Filters, of a diameter suitable for use with the samplers:
6.2.2.1 Quartz Fiber Filters. Quartz Fiber Filters.
6.2.2.2 Membrane Filters, PVC, 5-μm pore size or below, and
6.2.2.3 Membrane Filters, PTFE, 5-μm pore size or below.
6.2.3 Impregnated Filters, suitable for sampling of acid gases, for example, 25-mm diameter quartz fiber filters impregnated
with 200 μL of 265 g/L 265-g/L sodium carbonate solution (see 6.7.17.8.1) or 37-mm diameter quartz fiber filters impregnated with
500 μL of 106 g/L 106-g/L sodium carbonate solution (see 6.7.27.8.2).
6.2.4 Spacer, of a diameter suitable for use with the samplers, for separating the prefilters and impregnated quartz fiber filters,
for example, polypropylene sleeves or PTFE-coated screens.
6.3 Sampling Pumps, with an adjustable flow rate and capable of maintaining the selected flow rate (between 1 L/min and 2
L/min for personal sampling pumps) to within 65 % of the nominal value throughout the sampling period.
The boldface numbers in parentheses refer to a list of references at the end of this standard.
D7773 − 19
6.4 Flow Meter, portable, capable of measuring the selected volumetric flow rate within 62 %, and calibrated against a primary
standard.
6.5 Ancillary Equipment:
6.5.1 Flexible Tubing, of a diameter suitable for making a leak-proof connection form the sampler to the sampling pump.
6.5.2 Belts or Harnesses, to which the sampling pump can be conveniently fixed for personal sampling.
6.6 Laboratory Equipment:
6.6.1 Ion chromatograph having the following components:
6.6.1.1 Pump—Capable of delivering a constant flow within the range 0.1 mL/min to 5 mL/min at a pressure of 15 MPa to 150
MPa.
6.6.1.2 Injection Valve—A low dead volume, non-metallic valve fitted with a sample loop having a volume of up to 500 μL, for
injecting the sample solution into the eluent stream.
6.6.1.3 Guard Column—A column, placed before the separator column, to protect the latter from fouling by particles or strongly
adsorbed organic constituents of the sample solution.
6.6.1.4 Separator Column:
(1) Separator Column for Suppressed Ion Chromatography: A column packed with high capacity pellicular anion exchange
resin, suitable for resolving nitrates chlorides or bromides from other inorganic anions.
(2) Separator Column for Non-suppressedNon-Suppressed Ion Chromatography: A column packed with silica or organic
polymers, suitable for resolving chloride, bromide, and nitrate from other inorganic anions.
6.6.1.5 Suppressor Module—A module to reduce the total conductivity of the eluent suitable for use with the separator column.
6.6.1.6 Detector:
(1) Conductivity Detector: A low volume flow through with a non-metallic flow path conductivity detector.
NOTE 4—A conductivity detector can be used with both suppressed and non-suppressed ion chromatography
(2) Ultraviolet-visibleUltraviolet-Visible (UV-vis) Detector: A low volume flow through UV-vis detector with a non-metallic
flow path detector.
NOTE 5—A UV-vis detector can be used with non-suppressed ion chromatography for inverse UV detection.
6.6.1.7 Recorder, Integrator, or Computer—A device compatible with detector output, capable of recording detector response
as a function of time for the purpose of measuring peak height or area.
6.6.1.8 Eluent Reservoir—A container suitable for storing a manually prepared eluent solution.
6.6.1.9 Eluent generation system, for producing an eluent suitable for use with the selected separator column, as an alternative
to use of a manually prepared eluent (2).
6.6.2 Ultrasonic bath, preferably with a timer, suitable for use in the ultrasonic extraction method for hydrogen chloride, nitric
acid or hydrogen bromide.
6.6.3 pH Metermeter.
6.7 Laboratory Supplies:
NOTE 6—It is normally preferable to use plastic labware rather than glassware.
6.7.1 One-markOne-Mark Volumetric Flasks, of capacities between 20 mL, 100 mL, and 2 L.
6.7.2 One-markOne-Mark Pipets, complying with the requirements of ISO 648.
6.7.3 Disposable Screw-cap Polyethylene Vessels, of 15 mL 15-mL capacity.
6.7.4 Disposable Filters, PTFE, pore size 0.45 μm, for use in ion chromatography.
6.7.5 Disposable 2-mL or 5-mL Syringes, with luer lock connector, for use with disposable filters.
6.7.6 Cation Exchange Resin Cartridges, suitable for removal of carbonate from test solutions to be analyzed by
electronically-suppressed ion chromatography.
6.7.7 Autosampler Vials, of 1.5 mL-2 mL1.5-mL to 2-mL capacity.
6.7.8 Pipet Tips, plastic, disposable, of assorted sizes, as needed.
6.7.9 Labware, plastic (beakers, flasks, graduated cylinders, etc.), of assorted sizes, as needed.
6.7.10 Tweezers, manufactured from plastic or tipped with PTFE, for loading and unloading filters into samplers.
6.7.11 Personal Protective Wear, for example, respirators, masks, gloves, lab coats, safety eyewear, etc., as needed.
6.7.12 Other General Laboratory Supplies, as needed.
7. Reagents and Materials
7.1 Purity of Reagents—Unless otherwise stated, minimum purity of reagents shall be reagent grade.
7.2 Water—Unless otherwise indicated, references to water shall be understood to mean reagent-grade, as defined by Type 1
Type 1 of Specification D1193 (ASTM Type 1 water: minimum resistance of 18 MΩ-cm or equivalent)equivalent).
- - -
7.3 Stock Standard Solution, 1000 mg/L anions (Cl , Br , NO ) in water: Use a commercial standard solution with a certified
concentration, for example, 1000 mg/L of chloride, bromide and nitrate traceable to national standards. Observe the
manufacturer’smanufacturer’s expiration date or recommended shelf life.
D7773 − 19
- - -
7.4 Working Standard Solution, 100 mg/L anions (Cl , Br , NO ) in water: Accurately pipet appropriate volumes, for example,
10 mL, of the Calibrationcalibration stock solution I (6.7.27.3) into a 100 mL 100-mL one-mark volumetric flask, dilute to the mark
with water, stopper, and mix thoroughly. Prepare this solution fresh monthly.
7.5 Sodium Carbonate (Na CO ), anhydrous, purity >99.9 % (m ⁄m).
2 3
7.6 Sodium Hydrogen Carbonate (NaHCO ), purity >99.5 % (m/m).
7.7 Sodium Carbonate Impregnation Solution:
7.7.1 Sodium Carbonate Impregnation Solution for 25 mm 25-mm Filters, 2.5 mol/L (265 g/L). Dissolve 26.5 g Na CO in
2 3
water, quantitatively transfer the solution into a 100 mL 100-mL one-mark volumetric flask, dilute to the mark with water, stopper,
and mix thoroughly.
7.7.2 Sodium Carbonate Impregnation Solution for 37 mm 37-mm Filters, 1 mol/L (106 g/L). Dissolve 10.6 g Na CO in water.
2 3
Quantitatively transfer the solution into a 100 mL 100-mL one-mark volumetric flask, dilute to the mark with water, stopper, and
mix thoroughly.
7.8 Reagents for Chemically Suppressed Ion Chromatography:
NOTE 7—The sodium carbonate/sodium hydrogen carbonate eluent prescribed below is an example that can be used with separator columns for the
determination of chloride, bromide and nitrate by chemically suppressed ion chromatography. The column manufacturer’smanufacturer’s literature will
give information on the composition of the eluent to be used with a specific column type.
7.8.1 Sodium Carbonate/Sodium Hydrogen Carbonate Extraction and Eluent Stock Solution, 0.62 mol/L Na CO and 0.069
2 3
mol/L NaHCO . Dissolve 6.6 g of sodium carbonate and 0.58 g sodium hydrogen carbonate in 25 mL of water and swirl to mix.
Quantitatively transfer the solution to a 100 mL 100-mL one-mark volumetric flask, dilute to the mark with water, stopper, and
mix thoroughly.
7.8.2 Sodium Carbonate/Sodium Hydrogen Carbonate Extraction and Eluent Solution, 0.0031 mol/L Na CO and 0.00035
2 3
mol/L NaHCO . Transfer 10 mL of sodium carbonate/sodium hydrogen carbonate stock solution to a 2 L 2-L one-mark volumetric
flask, dilute to the mark with water, stopper, and mix thoroughly.
7.8.3 Potassium Hydroxide Cartridge, suitable for use with the eluent generation system, if appropriate.
7.9 Reagents for Non-Suppressed Ion Chromatography:
NOTE 8—The phthalic acid and borate/gluconate solutions prescribed below are two examples of eluents used for the determination of HCl, HBr, and
HNO using electronically suppressed ion chromatography. The column manufacturer’s literature will give information on the composition of the eluent
to be used with a specific column type.
7.9.1 Phthalic Acid (C H O ), mass fraction >99.5 %.
8 6 4
7.9.2 Acetonitrile (C H N), HPLC grade.
2 3
7.9.3 Methanol (CH OH), HPLC grade.
7.9.4 Lithium Hydroxide Monohydrate (LiOH×H O), mass fraction >99.5 %.
7.9.5 Boric acid (H BO ), mass fraction >99.8 %.
3 4
7.9.6 Gluconic Acid Solution, mass fraction approximately 50 % of D-gluconic acid (C H O ) in water.
6 12 7
7.9.7 Glycerol (C H O ), mass fraction >99 %.
3 8 3
7.9.8 Phthalic Acid Extraction and Eluent Stock Solution, 0.1 mol/L phthalic acid in 9:1 acetonitrile:methanol. Dissolve 1.66
g of phthalic acid in 900 mL of acetonitrile and 100 mL of methanol in a suitable 1-L vessel and mix thoroughly.
7.9.9 Lithium Hydroxide Solution, 1 mol/L lithium hydroxide. Dissolve 4.2 g of lithium hydroxide monohydrate in water.
Quantitatively, transfer the solution into a 100 mL 100-mL one-mark volumetric flask, dilute to the mark with water, stopper, and
mix thoroughly.
7.9.10 Phthalic Acid Extraction and Eluent Solution, for example, 0.005 mol/L phthalic acid, pH 4.2. Transfer an appropriate
volume, for example, 50 mL, of phthalic acid solution to a 1 L 1-L one-mark volumetric flask, add approximately 900 mL of water,
adjust to pH 4.2 with lithium hydroxide solution and dilute to the mark with water.
7.9.11 Borate/Gluconate Extraction Andand Eluent Stock Solution. Dissolve 17 g of boric acid, 4.8 g of lithium hydroxide
monohydrate, 8.8 mL of gluconic acid and 62.5 mL of glycerol in water. Quantitatively, transfer the solution into a 500 mL 500-mL
one-mark volumetric flask, dilute to the mark with water, stopper, and mix thoroughly.
7.9.12 Borate/Gluconate Extraction Andand Eluent Solution. Transfer 15 mL of borate/gluconate stock solution and 120 mL of
acetonitrile to a 1 L 1-L one-mark volumetric flask and dilute to the mark with water, stopper, and mix thoroughly.
8. Sampling
8.1 Filter Impregnation—Impregnate the quartz fiber filters with sodium carbonate impregnation solution (6.67.7) by
distributing the solution evenly on the filter. Ensure that the filter is completely moistened. Before use, dry the filter in a desiccator
at room temperature overnight.
8.2 Preparation of Samplers—Load each clean sampler with one impregnated filter (5.2.36.2.3) and one pre-filter (5.2.26.2.2),
and place a spacer between the two filters to prevent contamination. Label each sampler so that it can be uniquely identified, and
seal with its protective cover or plug.
D7773 − 19
8.3 Air Sampling—Collect workplace air samples for volatile inorganic acids in accordance with Test Method D7035. Use
samplers at their design flow rate and in accordance with the instructions provided by the manufacturer. Use personal sampling
pumps calibrated in accordance with Practice D5337.
8.4 Sample Transport:
8.4.1 Samplers with an Internal Cassette—For samplers with an internal filter cassette, remove the filter cassette from each
sampler and fasten with its lid or transport clip.
8.4.2 Samplers of Disposable Cassette Type—For samplers of the disposable cassette type, transport the samples to the
laboratory in the samplers in which they were collected.
8.5 Chain of Custody—If applicable, follow sampling chain-of-custody procedures to document sample traceability. Ensure that
the documentation that accompanies the samples is suitable for a chain of custody to be established in accordance with Guide
D4840.
9. Analysis
9.1 Wear appropria
...