ASTM D7035-21

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.
Designation: D7035 − 21
Standard Test Method for
Determination of Metals and Metalloids in Airborne
Particulate Matter by Inductively Coupled Plasma Atomic
Emission Spectrometry (ICP-AES)
This standard is issued under the fixed designation D7035; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
Calcium Phosphorus Uranium
Cesium Platinum Vanadium
1.1 This test method specifies a procedure for collection,
Chromium Potassium Yttrium
sample preparation, and analysis of airborne particulate matter Cobalt Rhodium Zinc
Copper Selenium Zirconium
for the content of metals and metalloids using inductively
Hafnium Silver
coupledplasma-atomicemissionspectrometry(ICP-AES).The
1.7 This test method is not applicable to the sampling of
method is generally applicable to occupational exposure moni-
elemental mercury, or to inorganic compounds of metals and
toring.
metalloids that are present in the gaseous or vapor state.
1.2 This test method is applicable to personal sampling of
1.8 No detailed operating instructions are provided because
the inhalable or respirable fraction of airborne particles and to
of differences among various makes and models of suitable
area sampling.
ICP-AES instruments. Instead, the analyst shall follow the
1.3 Thistestmethodshouldbeusedbyanalystsexperienced
instructions provided by the manufacturer of the particular
intheuseofICP-AES,theinterpretationofspectralandmatrix
instrument. This test method does not address comparative
interferences, and procedures for their correction.
accuracy of different devices or the precision between instru-
1.4 This test method specifies a number of alternative ments of the same make and model.
methods for preparing test solutions from samples of airborne
1.9 Thistestmethodcontainsnotesthatareexplanatoryand
particulate matter. One of the specified sample preparation
are not part of the mandatory requirements of this test method.
methods is applicable to the measurement of soluble metal or
1.10 The values stated in SI units are to be regarded as
metalloid compounds. Other specified methods are applicable
standard. No other units of measurement are included in this
to the measurement of total metals and metalloids.
standard.
1.5 Itistheuser’sresponsibilitytoensurethevalidityofthis
1.11 This standard does not purport to address all of the
test method for sampling materials of untested matrices.
safety concerns, if any, associated with its use. It is the
1.6 The following is a non-exclusive list of metals and
responsibility of the user of this standard to establish appro-
metalloids for which one or more of the sample dissolution
priate safety, health, and environmental practices and deter-
methods specified in this document is applicable. However,
mine the applicability of regulatory limitations prior to use.
there is insufficient information available on the effectiveness
1.12 This international standard was developed in accor-
of dissolution methods for those elements in italics.
dance with internationally recognized principles on standard-
Aluminum Indium Sodium
ization established in the Decision on Principles for the
Antimony Iron Strontium
Development of International Standards, Guides and Recom-
Arsenic Lead Tantalum
mendations issued by the World Trade Organization Technical
Barium Lithium Tellurium
Beryllium Magnesium Thallium Barriers to Trade (TBT) Committee.
Bismuth Manganese Tin
Boron Molybdenum Titanium
2. Referenced Documents
Cadmium Nickel Tungsten
2.1 ASTM Standards:
D1193Specification for Reagent Water
This test method is under the jurisdiction of ASTM Committee D22 on Air
Quality and is the direct responsibility of Subcommittee D22.04 on WorkplaceAir
Quality. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2021. Published October 2021. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2004. Last previous edition approved in 2016 as D7035–16. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D7035-21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7035 − 21
D1356Terminology Relating to Sampling and Analysis of ISO20581Workplaceatmospheres—Generalrequirements
Atmospheres for the performance of procedures for the measurement of
D4185Test Method for Measurement of Metals in Work- chemical agents
placeAtmospheres by FlameAtomicAbsorption Spectro-
photometry
3. Terminology
D4840Guide for Sample Chain-of-Custody Procedures
3.1 Definitions—For definitions of pertinent terms not listed
D5337Practice for Flow RateAdjustment of Personal Sam-
here, see Terminology D1356.
pling Pumps
3.2 Definitions of Terms Specific to This Standard:
D6062GuideforPersonalSamplersofHealth-RelatedAero-
3.2.1 atomic emission—characteristic radiation emitted by
sol Fractions
an electronically excited atomic species.
D6785TestMethodforDeterminationofLeadinWorkplace
3.2.1.1 Discussion—In atomic (or optical) emission
Air Using Flame or Graphite FurnaceAtomicAbsorption
spectrometry, a very high-temperature environment, such as a
Spectrometry
plasma, is used to create excited state atoms. For analytical
D7202Test Method for Determination of Beryllium in the
purposes,characteristicemissionsignalsfromelementsintheir
WorkplacebyExtractionandOpticalFluorescenceDetec-
excited states are then measured at specific wavelengths.
tion
D7439Test Method for Determination of Elements in Air-
3.2.2 axial plasma, n—a horizontal inductively coupled
borne Particulate Matter by Inductively Coupled Plasma-
plasma that is viewed end-on (versus radially; see 3.2.31).
–Mass Spectrometry
3.2.3 background correction, n—the process of correcting
D7440Practice for Characterizing Uncertainty in Air Qual-
theintensityatananalyticalwavelengthfortheintensitydueto
ity Measurements
the underlying spectral background of a blank. ISO 15202
D8344Practice for Ammonium Bifluoride and Nitric Acid
3.2.4 background equivalent concentration, n—the concen-
Digestion of Airborne Dust and Dust-Wipe Samples for
tration of a solution that results in an emission signal of
the Determination of Metals and Metalloids
equivalent intensity to the background emission signal at the
D8358GuideforAssessmentandInclusionofWallDeposits
analytical wavelength. ISO 15202
in the Analysis of Single-Stage Samplers for Airborne
3.2.5 batch, n—a group of field or quality control (QC)
Particulate Matter
E288Specification for Laboratory Glass Volumetric Flasks samples that are collected or processed together at the same
time using the same reagents and equipment. E3203
E438Specification for Glasses in Laboratory Apparatus
E882Guide for Accountability and Quality Control in the
3.2.6 blank solution, n—solution prepared by taking a re-
Chemical Analysis Laboratory
agent blank or field blank through the same procedure used for
E1154Specification for Piston or Plunger Operated Volu-
sample dissolution.
metric Apparatus
3.2.7 calibrationblanksolution,n—calibrationsolutionpre-
E1370Guide for Air Sampling Strategies for Worker and
pared without the addition of any stock standard solution or
Workplace Protection
working standard solution. ISO 15202
E1613Test Method for Determination of Lead by Induc-
3.2.7.1 Discussion—The concentration of the analyte(s) of
tively Coupled Plasma Atomic Emission Spectrometry
interest in the calibration blank solution is taken to be zero.
(ICP-AES), Flame Atomic Absorption Spectrometry
3.2.8 calibration solution, n—solution prepared by dilution
(FAAS), or Graphite Furnace Atomic Absorption Spec-
of the stock standard solution(s) or working standard
trometry (GFAAS) Techniques (Withdrawn 2021)
solution(s), containing the analyte(s) of interest at a concen-
E1728PracticeforCollectionofSettledDustSamplesUsing
tration(s) suitable for use in calibration of the analytical
Wipe Sampling Methods for Subsequent Lead Determi-
instrument. ISO 15202
nation
3.2.8.1 Discussion—The technique of matrix matching is
E3203Test Method for Determination of Lead in Dried
normally used when preparing calibration solutions.
Paint, Soil, and Wipe Samples by Inductively Coupled
Plasma-Optical Emission Spectroscopy (ICP-OES)
3.2.9 chemical agent, n—any chemical element or
2.2 ISO Standards:
compound, on its own or admixed as it occurs in the natural
ISO 4225Air quality — General aspects
state or as produced, used or released, including release as
ISO 7708Particle size definitions for health-related sam-
waste, by any work activity, whether or not produced inten-
pling
tionally and whether or not placed on the market. ISO 4225
ISO 15202Workplace air — Determination of metals and
3.2.10 continuing calibration blank (CCB), n—a solution
metalloids in airborne particulate matter by inductively
containing no analyte added, that is used to verify blank
coupled plasma atomic emission spectrometry (3 parts)
response and freedom from carryover. E1613
ISO 18158Workplace atmospheres — Terminology
3.2.10.1 Discussion—The measured concentration of the
CCB is to be (at most) less than five times the instrumental
The last approved version of this historical standard is referenced on
detection limit.
www.astm.org.
3.2.11 excitation interferences, n—non-spectral interfer-
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. ences that manifest as a change in sensitivity due to a change
D7035 − 21
in inductively coupled plasma conditions when the matrix of a 3.2.23 load coil, n—a length of metal tubing (typically
calibration or test solution is introduced into the plasma. ISO copper) which is wound around the end of an inductively
15202 coupled plasma torch and connected to the radio frequency
generator. ISO 15202
3.2.12 field blank, n—sampling media (for example, an air
3.2.23.1 Discussion—The load coil is used to inductively
filter) that is exposed to the same handling as field samples,
coupleenergyfromtheradiofrequencygeneratortotheplasma
except that no sample is collected (that is, no air is purposely
discharge.
drawn through the sampler). D6785
3.2.24 matrix interference, n—interferenceofanon-spectral
3.2.12.1 Discussion—Analysisresultsfromfieldblankspro-
nature which is caused by the sample matrix.
vide information on the analyte background level in the
3.2.24.1 Discussion—Matrix matching involves preparing
sampling media, combined with the potential contamination
calibration solutions in which the concentrations of acids and
experienced by samples collected within the batch resulting
other major solvents and solutes are matched with those in the
from handling.
test solutions. ISO 15202
3.2.13 inductively coupled plasma (ICP), n—a high-
3.2.25 measuring procedure, n—procedure for sampling
temperature discharge generated by a flowing conductive gas,
andanalyzingoneormorechemicalagentsintheair,including
normallyargon,throughamagneticfieldinducedbyaloadcoil
storage and transportation of the sample(s). ISO 15202
that surrounds the tubes carrying the gas. ISO 15202
3.2.26 method quantitation limit (MQL), n—the minimum
3.2.14 inductively coupled plasma (ICP) torch, n—a device
concentration of an analyte that can be measured with accept-
consisting of three concentric tubes, the outer two usually
able precision, ordinarily taken to be at least ten times the
madefromquartz,thatisusedtosupportandintroducesample
standard deviation of the mean blank signal (1).
into an ICP discharge. ISO 15202
3.2.26.1 Discussion—The MQL is also known as the limit
3.2.15 injectortube,n—theinnermosttubeofaninductively
of quantitation.
coupled plasma torch, usually made of quartz or ceramic
3.2.27 nebulizer, n—a device used to create an aerosol from
materials, through which the sample aerosol is introduced to
a liquid. ISO 15202
the plasma. ISO 15202
3.2.28 outer (plasma) argon flow, n—the flow of argon gas
3.2.16 inner (nebulizer) argon flow, n—the flow of argon
thatiscontainedbetweentheouterandintermediatetubesofan
gasthatisdirectedthroughthenebulizerandcarriesthesample
inductivelycoupledplasmatorch;typically7to15L/min. ISO
aerosol through the injector and into the plasma; typically 0.5
L/min – 2 L/min. ISO 15202
3.2.29 personal sampler, n—a device attached to a person
3.2.17 instrumental detection limit (IDL), n—the lowest
that samples air in the breathing zone. ISO 18158
concentration at which the instrumentation can distinguish
3.2.30 pneumatic nebulizer, n—a nebulizer that uses high-
analyte content from the background generated by a minimal
speed gas flows to create an aerosol from a liquid. ISO 15202
matrix. E1613
3.2.31 radialplasma,n—aninductivelycoupledplasmathat
3.2.17.1 Discussion—The IDL pertains to the maximum
is viewed from the side (versus axial).
capabilityofaninstrumentandshouldnotbeconfusedwiththe
method detection limit (MDL).
3.2.32 respirable fraction, n—the mass of inhaled particles
penetrating to the unciliated airways. ISO 7708
3.2.18 interelement correction, n—a spectral interference
correction technique in which emission contributions from
3.2.33 sample dissolution, n—the process of obtaining a
interfering elements that emit radiation at the analyte wave-
solution containing the analyte(s) of interest from a sample.
length are subtracted from the apparent analyte emission after
This may or may not involve complete dissolution of the
measuring the interfering element concentrations at other
sample. D6785
wavelengths. ISO 15202
3.2.34 sample preparation, n—all operations carried out on
3.2.19 intermediate (auxiliary) argon flow, n—the flow of
a sample, after transportation and storage, to prepare it for
argongasthatiscontainedbetweentheintermediateandcenter analysis, including transformation of the sample into a mea-
(injector) tubes of an inductively coupled plasma torch; typi-
surable state, where necessary. ISO 15202
cally 0.1 L/min – 2 L/min. ISO 15202
3.2.35 sampling location, n—a specific area within a sam-
3.2.20 internal standard, n—a non-analyte element, present pling site that is subjected to sample collection. E1728
3.2.35.1 Discussion—Multiple sampling locations are com-
in all calibration, blank, and sample solutions, the signal from
which is used to correct for non-spectral interference or monly designated for a single sampling site.
improve analytical precision. ISO 15202
3.2.36 sampling site, n—a local geographic area that con-
tains the sampling locations. E1728
3.2.21 limit value, n—referencefigureforconcentrationofa
3.2.36.1 Discussion—Asamplingsiteisgenerallylimitedto
chemical agent in air. ISO 15202
an area that is easily covered by walking.
3.2.22 linear dynamic range, n—therangeofconcentrations
over which the calibration curve for an analyte is linear. It
extends from the detection limit to the onset of calibration
The boldface numbers in parentheses refer to a list of references at the end of
curvature. ISO 15202 this standard.
D7035 − 21
3.2.37 spectral interference, n—an interference caused by workplace air are converted to water- or acid-soluble ions in
the emission from a species other than the analyte of interest. sample solutions by one or more of the sample dissolution
ISO 15202 methods specified.
3.2.38 spray chamber, n—a device placed between a nebu- 4.4 Test solutions prepared from the sample solutions after
lizer and an inductively coupled plasma torch whose function sample dissolution are analyzed using inductively coupled
istoseparateoutaerosoldropletsinaccordancewiththeirsize, plasma-atomic emission spectrometry (ICP-AES) to determine
so that only very fine droplets pass into the plasma, and large the concentration of target elements in the sampled air.
NOTE1—Thesamplingandsamplepreparationproceduresdescribedin
droplets are drained or pumped to waste. ISO 15202
this standard may be suitable for preparation of samples for subsequent
3.2.39 stock standard solution, n—solution used for prepa-
analysis by other methods besides ICP-AES (for example: flame atomic
ration of working standard solutions and/or calibration solu-
absorption spectrometry (see Practice D4185), graphite furnace atomic
absorption spectrometry, inductively coupled plasma – mass spectrometry
tions or both, containing the analyte(s) of interest at a certified
(ICP-MS); see Test Method D7439), electroanalysis, and so forth).
concentration(s) traceable to primary standards (National In-
stitute of Standards and Technology or international measure-
5. Significance and Use
ment standards).
5.1 The health of workers in many industries is at risk
3.2.40 transport interference, n—non-spectral interference
through exposure by inhalation to toxic metals and metalloids.
caused by a difference in viscosity, surface tension, or density
Industrialhygienistsandotherpublichealthprofessionalsneed
between the calibration and test solutions (for example, due to
to determine the effectiveness of measures taken to control
differences in dissolved solids content, type and concentration
workers’ exposures, and this is generally achieved by making
of acid, and so forth). ISO 15202
workplace air measurements. This test method has been
3.2.40.1 Discussion—Such differences produce a change in
promulgated in order to make available a standard methodol-
nebulizer efficiency and hence in the amount of analyte
ogy for making valid exposure measurements for a wide range
reaching the plasma.
of metals and metalloids that are used in industry. It will be of
benefit to agencies concerned with health and safety at work;
3.2.41 ultrasonic nebulizer, n—a nebulizer in which the
aerosol is created by flowing a liquid across a surface that is industrial hygienists and other public health professionals;
oscillating at an ultrasonic frequency. ISO 15202 analytical laboratories; industrial users of metals and metal-
loids and their workers, and other groups.
3.2.42 viewing height (for a radial plasma), n—the position
in a radial plasma from where the emission measured origi- 5.2 This test method specifies a generic method for deter-
mination of the mass concentration of metals and metalloids in
nates;generallygivenasthedistance,inmillimetres,abovethe
load coil. ISO 15202 workplace air using ICP-AES.
5.3 The analysis results can be used for the assessment of
3.2.43 workplace, n—the defined area or areas in which the
work activities are carried out. ISO 18158 workplaceexposurestometalsandmetalloidsinworkplaceair.
5.4 Whensamplingandanalysisiscarriedoutinaccordance
3.2.44 x-y centering (for an axial plasma), n—horizontal
and vertical adjustment of an axial plasma to establish optimal with this test method, the overall procedure normally satisfies
the performance requirements of ISO 20581.
viewing conditions, such that only emission from the central
NOTE 2—Refer to Guide E1370 for guidance on the development of
channel of the plasma is measured. ISO 15202
appropriate exposure assessment and measurement strategies.
4. Summary of Test Method
6. Sampling Apparatus and Materials
4.1 A known volume of air is drawn through a sampler
6.1 Sampling Equipment:
containing a sampling substrate (such as a filter, foam, or filter
6.1.1 Inhalable Samplers, designed to collect the inhalable
capsule) to collect airborne particles suspected to contain
fraction of airborne particles (see Guide D6062), for use when
metalsormetalloids,orboth.Thesamplingdevice(sampler)is
the exposure limits for metals and metalloids of interest apply
ordinarily designed to collect the inhalable fraction of airborne
to the inhalable fraction.
particles; however, sampling of the respirable fraction (or
NOTE 3—In general, personal samplers for collection of airborne
other) is also possible (see Guide D6062; ISO 7708).
particles do not exhibit the same size-selective characteristics if used for
area sampling.
4.2 The filter (or filter capsule) and collected sample are
NOTE 4—Some inhalable samplers are designed to collect the inhalable
subjected to a dissolution procedure in order to extract target
fraction of airborne particles on the filter, and any particulate matter
elemental analytes of interest. The sample dissolution proce-
deposited on the internal surfaces of the sampler (separate from the filter)
dure may consist of one or two methodologies: one for soluble
is not considered part of the sampled air. Other inhalable samplers are
or one for total metals and metalloids, or both. Candidate
designed such that all airborne particles which pass through the entry
orifice(s) are of interest, hence particulate matter deposited on the inner
procedures, based on hot plate, hot block, or microwave
walls of the sampler does form part of the sample. In such cases it will be
digestion, are used for dissolution of filter samples for subse-
necessary to account for particulate material collected on the inner walls
quent determination of ‘total’ or ‘soluble’ inhalable (or respi-
of the sampler (in addition to that collected on the filter). Refer to Guide
rable) metals and metalloids.
D8358 for additional information.
4.3 In general, particulate metals and metalloids (and their 6.1.2 Respirable Samplers, designed to collect the respi-
compounds) that are commonly of interest in samples of rable fraction of airborne particles (see Guide D6062), for use
D7035 − 21
when the exposure limits for the metals and metalloids of the metals and metalloids of interest to be determined with
interest apply to the respirable fraction. acceptable overall uncertainty at levels of industrial hygiene
significance.
NOTE 5—Cyclone-type samplers are typically used for personal
7.1.1.1 For metals and metalloids with short-term exposure
sampling, while cascade impactors are often used to characterize the
limits, the sampling time shall be as close as possible to the
particle size distribution in area sampling.
NOTE 6—In lieu of inhalable and respirable samplers, multi-fraction reference period, which is typically 15 minutes (minimum 5
samplers, where applicable, may be used to collect airborne particles of
minutes, maximum 30 minutes).
alternative size distributions (see Guide D6062).
7.1.1.2 For metals and metalloids with long-term exposure
NOTE 7—Some respirable samplers are designed to collect the respi-
limits,samplesshallbecollectedfortheentireworkingperiod,
rable fraction of airborne particles on the filter, and any particulate matter
if possible; otherwise, obtain consecutive samples during a
deposited on the internal surfaces of the sampler (separate from the filter)
is not considered part of the sampled air. Other respirable samplers are number of representative work episodes. The sampling time
designed such that all airborne particles which pass through the entry
shall be as close as possible to the reference period, which is
orifice(s) are of interest, hence particulate matter deposited on the inner
typically 8 hours (minimum 7 hours, maximum 10 hours).
walls of the sampler does form part of the sample. In such cases it will be
necessary to account for particulate material collected on the inner walls
7.2 Preparation for Sampling:
of the sampler (in addition to that collected on the filter). Refer to Guide
7.2.1 Handling of Filters—To minimize the risk of damage
D8358 for additional information.
or contamination, handle filters only with clean flat-tipped
6.1.3 Filters or Filter Capsules, of a diameter suitable for
forceps, and in a clean, uncontaminated area free from high
use with the samplers, and a collection efficiency of not less
concentrations of air particles.
than 99% for particles with a 0.3 µm diffusion diameter (see
7.2.2 Cleaning of Samplers—Unless disposable filter cas-
ISO 7708).The filters (or filter capsules) shall have a very low
settes are used, clean the samplers before use. Disassemble the
background metal content (typically less than 0.1 µg of each
samplers (if necessary), soak in detergent solution, rinse
metal or metalloid of interest per filter), and they should be
thoroughly with water, wipe with absorptive tissue, and allow
compatible with the anticipated sample preparation method.
to dry before (re)assembly.
See Appendix X1 for guidance on filter selection.
NOTE 9—A laboratory washing machine may be used for cleaning of
samplers.
NOTE 8—Filters of diameter 25 mm or 37 mm are commonly used for
sampling airborne particles in workplaces.
7.2.3 Loading Filters (or Filter Capsules) into Samplers—
6.1.4 Sampling Pumps, with an adjustable flow rate, por- Load clean samplers with unused, clean filters (or filter
table. Pumps shall be capable of maintaining the selected flow capsules), seal each sampler with its protective cover or plug
rate between 1 L/min and 5 L/min for personal or area (to prevent contamination), and label each sampler so that it
sampling,andtowithin 65%ofthenominalvaluethroughout can be uniquely identified.
thesamplingperiod.Forpersonalsampling,thepumpsshallbe 7.2.4 Setting the Flow Rate—In a clean area, where the
battery-powered, and they shall be capable of being worn by concentration of air particles is low, connect each loaded
the worker without impeding normal work activity. sampler to a sampling pump, ensuring no leakage. Remove the
6.1.5 Flow Meter, portable, with an accuracy that is suffi- protective cover or plug from each sampler, and switch on the
sampling pump. If necessary, allow the sampling pump oper-
cient to enable the volumetric flow rate to be measured to
within 62%. The calibration of the flow meter shall be ating conditions to stabilize. Attach the flow meter to the
sampler so that it measures the flow through the inlet orifice of
checkedagainstaprimarystandard,thatis,aflowmeterwhose
accuracy is traceable to national standards. the sampler, and set the required volumetric flow rate between
1 and 5 L/min. Ensure that the flow rate is adjusted in
6.1.6 Flexible Tubing, of a diameter suitable for making a
accordance with Practice D5337. Switch off the sampling
leak-proof connection from the sampling pumps to the sam-
pump and seal the sampler with its protective cover or plug (to
plers.
prevent contamination during transport to the sampling loca-
6.1.7 Belts or Harnesses, to which sampling pumps can
tion).
conveniently be fixed for personal sampling (except where the
pumps are small enough to fit in workers’ pockets).
NOTE10—Higher-flowsamplers(to>10L/min)areavailableforusein
6.1.8 Clips, for attaching samplers to the workers’clothing
special cases.
within the breathing zone.
7.2.5 Field Blanks—Retain as blanks, at least one unused
6.1.9 Flat-tipped Forceps, for loading and unloading filters
loaded sampler from each batch of twenty prepared (that is, a
into samplers.
minimum frequency of 5%). The minimum number of field
6.1.10 Filter Transport Cassettes,orsimilar(ifrequired),in
blanks to collect for each batch of samples used is three. Treat
which to transport samples to the laboratory.
these in the same manner as those used for sampling (with
6.1.11 Watch or Clock, for use in recording of starting and
respect to storage and transport to and from the sampling
ending times of sampling periods.
location),butdrawnoairthroughthefilters(orfiltercapsules).
Label these samples in the same fashion as the collected
7. Sampling Procedure
samples.
7.1 Sampling Period:
7.3 Sampling Position:
7.1.1 Select a sampling period that is appropriate for the 7.3.1 Personal Sampling—The sampler shall be positioned
measurement task, but ensure that it is long enough to enable in the worker’s breathing zone, as close to the mouth and nose
D7035 − 21
as is reasonably practicable, for instance, fastened to the 7.5.4 Transport the samples to the laboratory in a container
worker’s lapel or shirt collar.Attach the sampling pump to the that has been designed to prevent damage to the samples in
worker in a manner that causes minimum inconvenience, for transit, and which has been labeled to ensure proper handling.
example, to a belt around the waist. 7.5.5 Chain of Custody—Follow sampling chain of custody
procedures to ensure sample traceability. Ensure that the
7.3.2 Area Sampling—The sampler shall be positioned ei-
documentation which accompanies the samples is suitable for
ther: (1) in a position that is sufficiently remote from the work
a chain of custody to be established in accordance with Guide
processes, in order to characterize the background level(s) of
D4840.
metalsandmetalloidsintheworkplace;or (2)inapositionthat
is near a suspected source of workplace air contamination, in
8. Hazards
ordertoassesswhetherhighlevelsofmetalsandmetalloidsare
8.1 Concentrated nitric acid is corrosive and oxidizing, and
generated by the work activity.
nitric acid vapor is an irritant.Avoid exposure by contact with
7.4 Collection of Samples:
the skin or eyes, or by inhalation of fumes. Use suitable
7.4.1 When ready to begin sampling, remove the protective
personal protective equipment (including impermeable gloves,
cover or plug from the sampler, and switch on the sampling safety goggles, laboratory coat, and so forth) when working
pump.Recordthetimeandflowrateatthestartofthesampling withconcentratednitricacid,andcarryoutopen-vesselsample
period. dissolution with nitric acid in a fume hood.
7.4.2 For long-term sampling, periodically (ordinarily a
8.2 Concentratedperchloricacidiscorrosiveandoxidizing,
minimumofevery2hours)checktheflowrateofthesampling
and its vapor is an irritant. Perchloric acid forms explosive
pump (using the flow meter), and also check the sampler for
compounds with organics and many metal salts. Avoid expo-
overloading. If the flow rate has changed significantly (65%),
surebycontactwiththeskinoreyes,orbyinhalationoffumes.
consider the sample to be invalid. If the sampler shows
Use suitable personal protective equipment (including imper-
evidence of overloading (for example, as evidenced by excess
meable gloves, safety goggles, laboratory coat, and so forth)
dustloadingwithinthesampler),replaceitwithanewsampler
when working with perchloric acid. Carry out sample dissolu-
(that is, take consecutive samples (see Guide E1370)).
tion with perchloric acid in a fume hood with a scrubber unit
that is specially designed for use with HClO . See Appendix
NOTE11—Owingtogreatersamplingcapacity,filtercapsulesareuseful
X2 for further pertinent safety information.
for sampling in high-dust environments.
8.3 Concentrated hydrofluoric acid is highly corrosive, and
7.4.3 Attheendofthesamplingperiod,recordthetimeand
is very toxic by inhalation or contact with the skin. Avoid
determine the duration of the sampling period. Measure the
exposure by contact with the skin or eyes, or by inhalation of
flow rate at the end of the sampling period using the flow
HF vapor. It is essential to use suitable personal protective
meter, and record the measured value. Consider the sample to
equipment, including impermeable gloves and eye protection)
be invalid if there is evidence that the sampling pump was not
when working with HF. Use a fume hood when working with
operating properly throughout the sampling period.
concentrated HF and when carrying out open-vessel dissolu-
7.4.4 Record the sample identity and all relevant sampling
tion with HF. See Appendix X2 for further pertinent safety
data (such as work activity, sampling period, sampling
information.
location(s), mean flow rate, volume of air sampled). Calculate
8.4 Concentrated hydrochloric acid is corrosive, and HCl
the mean flow rate by averaging the flow rates at the start and
vapor is an irritant.Avoid exposure by contact with the skin or
at the end of the sampling period. Calculate the volume of air
eyes, or by inhalation of the vapor. Use suitable personal
sampled, in litres, by multiplying the mean flow rate (in litres
protectiveequipment(suchasgloves,faceshield,andsoforth)
per minute) by the duration of the sampling period (in
when working with HCl. Handle open vessels containing
minutes).
concentrated HCl in a fume hood. The vapor pressure of HCl
7.5 Transportation:
ishigh,sobewareofpressurebuildupinstopperedflaskswhen
7.5.1 Forreusablesamplersthatcollectairborneparticleson
preparing mixtures containing HCl.
the filter (or filter capsules), remove the filter (or filter capsule)
8.5 Concentrated sulfuric acid is corrosive and causes
from each sampler (with clean flat-tipped forceps), place in a
burns. Vapor produced when concentrated H SO is heated is
2 4
labeled filter transport cassette, and enclose. Take particular
an irritant. Avoid exposure by contact with the skin or eyes.
care to prevent the collected sample from becoming dislodged
Use suitable personal protective equipment (such as gloves,
from heavily loaded filters (unless filter capsules are used).
faceshield,andsoforth)whenworkingwithH SO .Carryout
2 4
Alternatively, transport samples to the laboratory within the
sample dissolution with H SO in a fume hood. Exercise
2 4
samplers in which they were collected.
cautionwhendilutingH SO withwater,asthisprocessisvery
2 4
7.5.2 For samplers that have an internal filter cassette,
exothermic. Do not add water to H SO , since it reacts
2 4
remove the cassette from each sampler and fasten with its lid
violently when mixed in this manner; rather, prepare H SO /
2 4
or transport clip, and transport the sample cassettes to the
H O mixtures by adding H SO to water.
2 2 4
laboratory.
9. Sample Preparation
7.5.3 For samplers of the disposable cassette type, transport
samples to the laboratory within the samplers in which they 9.1 Reagents for Sample Preparation—Details regarding
were collected. reagents that are required for individual sample dissolution
D7035 − 21
methods are given in Annex A1 through Annex A5. During in the workplace, and that none are produced in the processes
samplepreparation,useonlyreagentsofspectroscopicgradeor carried out, prepare test solutions for ICP-AES analysis using
better. one of the sample dissolution methods for total metals and
9.1.1 Water, complying with the requirements for ASTM metalloids and their compounds, as prescribed in Annex A2
(hot plate digestion), Annex A3 or Annex A5 (microwave
Type II water (see Specification D1193). It is recommended
that the water used be obtained from a water purification digestion), and Annex A4 (hot block digestion).
system that delivers ultra-pure water having a resistivity
NOTE 14—The methods prescribed in AnnexA2 through AnnexA4 are
greater than 18 MΩ-cm at 25°C.
not specific for soluble metal, or metalloid compounds, or both. However,
9.1.2 Nitric Acid (HNO ), concentrated, ρ ~1.42 g/mL in these circumstances, they may be used as an alternative to the method
described in Annex A1, if this is more convenient.
(~70% m/m). The concentration of metals and metalloids of
interest shall be less than 0.1 µg/mL.
9.3.2 Total Metals and Metalloids and their Compounds:
9.3.2.1 If results are required for total metals, or metalloids,
NOTE 12—It will be necessary to use reagents of higher purity in order
or both, and their compounds, select a suitable sample prepa-
to obtain adequate detection limits for some metals and metalloids, (for
example, beryllium). ration method from those specified in Annex A2 (hot plate
digestion), Annex A3 or Annex A5 (microwave digestion), or
9.1.3 Nitric Acid (HNO ), diluted 1+9 (10% v/v). Care-
Annex A4 (hot block digestion). Practice D8344 may also be
fully and slowly begin adding 50 mL of concentrated nitric
suitable. Take into consideration the applicability of each
acid to 450 mL of water.
method for dissolution of target metals and metalloids of
9.1.4 Laboratory Detergent, suitable for cleaning of sam-
interest from materials that could be present in the test
plers and laboratory ware.
atmosphere (refer to the clause on the effectiveness of the
9.2 Laboratory Apparatus for Sample Preparation—Details
sampledissolutionmethodintheannexinwhichthemethodis
regarding laboratory apparatus required for individual sample
specified), and the availability of the required laboratory
dissolutionmethodsaregiveninAnnexA1throughAnnexA5.
apparatus.
Ordinarylaboratoryapparatusarenotlisted,butareassumedto
NOTE 15—In selection of a sample preparation method, consideration
be present.
should be given to the metal or metalloid compounds that may be present
9.2.1 Disposable Gloves, impermeable and powder-free, to
in the test atmosphere. Some compounds, such as refractory metal oxides,
avoidthepossibilityofcontaminationandtoprotectthemfrom
may require a more robust sample preparation method than is required for
contact with toxic and corrosive substances. PVC gloves are
other compounds, or for the metals or metalloids themselves.
suitable.
9.3.2.2 Use the selected sample dissolution method to
9.2.2 Glassware, beakers and volumetric flasks complying
prepare, from which test solutions are prepared, sample solu-
with the requirements of Specification E288, made of borosili-
tions for analysis of total metals and metalloids and their
cate glass and complying with the requirements of Specifica-
compounds by ICP-AES.
tionE438.Glasswareshallbecleanedbeforeusebysoakingin
9.3.3 Deposits of Particles on Interior Sampler Surfaces—
1+1 nitric acid: water for at least 4 hours and then rinsing
Give consideration to metal and metalloid particles that may
thoroughly (at least 3 times) with ASTM Type 1 water, and
have deposited on interior sampler surfaces (for example, by
allowed to dry. Alternatively, before use, glassware shall be
becoming dislodged from the filter during transportation), and
cleaned by using commercial, automatic laboratory washing
determine whether the sample of interest should include such
equipment that performs a similar process.
particles. If the sample is determined to include such particles,
9.2.3 Flat-Tipped Forceps, polytetrafluoroethylene (PTFE)-
determine a methodology for removing them from the interior
tipped, for unloading filters from samplers or from filter
sampler surfaces and including them in the analysis. Guide
transport cassettes.
D8358 provides additional information and suggested method-
9.2.4 Piston-OperatedVolumetricPipettorsandDispensers,
ologies.
complying with the requirements of Specification E1154, for
NOTE 16—The use of filter capsules (in lieu of filters) alleviates this
pipettinganddispensingofleachsolutions,acids,andsoforth.
potential problem (2).
9.2.5 Plastic Bottles, 1 L capacity, with leak-proof screw
9.3.4 Mixed Exposures:
cap.
9.3.4.1 Ifanalyticalresultsarerequiredforbothsolubleand
9.3 Sample Preparation Procedures:
insoluble metals, or metalloids, or both, and their compounds,
first use the sample preparation procedure specified in Annex
NOTE 13—The sample dissolution methods described in Annex A1
throughAnnexA5aregenerallysuitableforusewithanalyticaltechniques
A1 to prepare sample solutions, from which test solutions are
otherthanICP-AES,forexample,atomicabsorptionspectrometry(AAS),
prepared, for determination of soluble metal and metalloid
and ICP-mass spectrometry (ICP-MS).
compounds for subsequent analysis by ICP-AES.
9.3.1 Soluble Metal and Metalloid Compounds:
9.3.4.2 Select a suitable sample dissolution method for total
9.3.1.1 Ifresultsarerequiredforsolublemetal,ormetalloid
metalsandmetalloidsandtheircompounds(specifiedinAnnex
compounds, or both, use the sample dissolution method speci- A2 for hot plate digestion, Annex A3 or Annex A5 for
fied in AnnexA1 to prepare sample solutions from which test
microwave digestion, or Annex A4 for hot block digestion).
solutions are prepared for analysis by ICP-AES. Use this procedure to treat undissolved material left over after
9.3.1.2 Alternatively, if it is known that no insoluble com- employing the preparation method for soluble metals and
poundsofthemetals,ormetalloids,orboth,ofinterestareused metalloids and their compounds (Annex A1), and prepare
D7035 − 21
sample solutions, from which test solutions are prepared, for 10. Analysis
subsequent analysis by ICP-AES.
10.1 Reagents for Analysis—During the analysis, use only
reagents of spectroscopic grade or better. The concentration of
9.4 Special Cases:
metals and metalloids of interest shall be less than 0.1 µg/mL.
9.4.1 Effectiveness of Sample Dissolution Procedure—If
there is any doubt about whether the selected sample prepara- NOTE 20—It will be necessary to use reagents of higher purity in order
to obtain adequate detection limits for some metals and metalloids (for
tion method will exhibit the required analytical recovery when
example, beryllium).
used for dissolution of the metals and metalloids of interest
10.1.1 Water, complying with the requirements for ASTM
from materials that could be present in the test atmosphere,
Type II water (see Specification D1193). It is recommended
determine its effectiveness for the particular application.
that the water used be obtained from a water purification
9.4.1.1 For total metals and metalloids, analytical recovery
system that delivers ultra-pure water having a resistivity
may be estimated by analyzing a performance evaluation
greater than 18 MΩ-cm at 25°C.
material of known composition that is similar in nature to the
10.1.2 Nitric Acid (HNO ), concentrated, ρ ~1.42 g/mL
materials being produced in the workplace, for example, a
(~70% m/m).
representative certified reference material (CRM).
10.1.3 Nitric Acid (HNO ), diluted1+9(10%v⁄v).
NOTE 17—It should be recognized that, for a bulk sample, certain Carefully and slowly begin adding 50 mL of concentrated
physical characteristics, such as particle size and agglomeration, could
nitric acid to 450 mL of water.
haveasignificantinfluenceontheefficacyofitsdissolution.Also,smaller
10.1.4 Ammonium Citrate Leach Solution, 17 g/L
amounts of material are often much more easily dissolved than greater
(NH ) HC H O and 5 g/L C H O ·H O. Weigh 17 g di-
4 2 6 5 7 6 8 7 2
quantities.
ammonium hydrogen citrate, (NH ) HC H O , and 5 g citric
4 2 6 5 7
9.4.1.2 For soluble metals and metalloids, analytical recov-
ammonium monohydrate, C H O ·H O, into a 500 mLbeaker.
6 8 7 2
ery is best determined by analyzing filters or filter capsules Add 250 mL of water and swirl to dissolve. Quantitatively
spiked with solutions containing known masses of the soluble transfer the solution into a 1-L volumetric flask, dilute to the
compound(s) of interest. mark with water, stopper and mix thoroughly. Check the
solution pH, and if necessary adjust the pH to 4.4 with
9.4.1.3 Recoveryshouldbeatleast90%oftheknownvalue
ammonia or citric acid.
for all elements included in the spiked filters or filter capsules,
10.1.5 Hydrochloric Acid (HCl), concentrated, ρ ~1.18
with a relative standard deviation of less than 5% (3). If the
g/mL, ~36% (m/m).
analytical recovery is outside the required range of acceptable
10.1.6 Hydrochloric Acid Leach Solution, 0.1 M.
values, investigate the use of an alternative sample dissolution
10.1.7 Perchloric Acid (HClO ), concentrated, ρ ~1.67
method. 4
g/mL, ~70% (m/m).
9.4.1.4 Do not use a correction factor to compensate for an
10.1.8 Sulfuric Acid (H SO ), concentrated, ρ ~1.84 g/mL,
2 4
apparently ineffective sample dissolution method, since this
~98% (m/m).
might equally lead to erroneous results.
10.1.9 Stock Standard Solutions:
9.4.2 DislodgementofParticlesDuringSampleTransport—
10.1.9.1 To prepare stock standard solutions, use commer-
Whenthefiltertransportcassettesorsamplersareopened,look
cial single-element or multi-element standard solutions with
for evidence that particles have become dislodged from the
certified concentrations traceable to primary standards (Na-
filter during transportation. If this appears to have occurred,
tional Institute of Standards and Technology or international
consider whether to discard the sample as invalid, or whether
measurement standards). Observe the manufacturer’s expira-
to wash the internal surfaces of the filter transport cassette or
tion date or recommended shelf life.
sampler into the sample dissolution vessel (with dilute nitric
NOTE 21—Commercially available stock solutions for metals and
acid) in order to recover the dislodged material. See Guide
metalloids typically have concentrations of 1000 or 10000 mg/L for
...