ASTM E3203-21

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: E3203 − 21
Standard Test Method for
Determination of Lead in Dried Paint, Soil, and Wipe
Samples by Inductively Coupled Plasma-Optical Emission
Spectroscopy (ICP-OES)
This standard is issued under the fixed designation E3203; 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 1.8 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 This test method specifies a procedure for analysis of
responsibility of the user of this standard to establish appro-
driedpaint,soil,anddustwipesamplescollectedinandaround
priate safety, health, and environmental practices and deter-
buildings and related structures for lead content using induc-
mine the applicability of regulatory limitations prior to use.
tively coupled plasma-optical emission spectroscopy (ICP-
1.9 This international standard was developed in accor-
OES).
dance with internationally recognized principles on standard-
1.2 Thistestmethodshouldbeusedbyanalystsexperienced
ization established in the Decision on Principles for the
intheuseofICP-OES,theinterpretationofspectralandmatrix
Development of International Standards, Guides and Recom-
interferences, and procedures for their correction. For determi-
mendations issued by the World Trade Organization Technical
nation of lead (Pb) and other metals in air by ICP-OES, see
Barriers to Trade (TBT) Committee.
Test Method D7035.
2. Referenced Documents
1.3 This test method cites specific methods for preparing
2.1 ASTM Standards:
test solutions of dried paint, soil, and wipe samples for
D1193Specification for Reagent Water
analysis.
D1356Terminology Relating to Sampling and Analysis of
1.4 Itistheuser’sresponsibilitytoensurethevalidityofthis
Atmospheres
test method for sampling materials of untested matrices.
D6785TestMethodforDeterminationofLeadinWorkplace
1.5 No detailed operating instructions are provided because Air Using Flame or Graphite FurnaceAtomicAbsorption
of differences among various makes and models of suitable Spectrometry
ICP-OES instruments. Instead, the analyst shall follow the D6966Practice for Collection of Settled Dust Samples
instructions provided by the manufacturer of the particular Using Wipe Sampling Methods for Subsequent Determi-
instrument. This test method does not address comparative nation of Metals
accuracy of different devices or the precision between instru- D7035Test Method for Determination of Metals and Met-
ments of the same make and model. alloids in Airborne Particulate Matter by Inductively
Coupled Plasma Atomic Emission Spectrometry (ICP-
1.6 Thistestmethodcontainsnotesthatareexplanatoryand
AES)
are not part of the mandatory requirements of this test method.
D7440Practice for Characterizing Uncertainty in Air Qual-
1.7 The values stated in SI units are to be regarded as
ity Measurements
standard. No other units of measurement are included in this
E631Terminology of Building Constructions
standard.
E882Guide for Accountability and Quality Control in the
1.7.1 Exception—The inch-pound and SI units shown for Chemical Analysis Laboratory
wipe sampling data are to be individually regarded as standard E1583Practice for Evaluating Laboratories Engaged in De-
for wipe sampling data. termination of Lead in Paint, Dust,Airborne Particulates,
and Soil Taken From and Around Buildings and Related
Structures
This test method is under the jurisdiction of ASTM Committee D22 on Air
Quality and is the direct responsibility of Subcommittee D22.12 on Sampling and
Analysis of Lead for Exposure and Risk Assessment. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2021. Published September 2021. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2019. Last previous edition approved in 2019 as E3203 – 19a. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E3203-21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3203 − 21
E1605Terminology Relating to Lead in Buildings 2.3 Other Standards:
E1613Test Method for Determination of Lead by Induc- EPA SW-846 Test Method 311 Toxicity Characteristic
Leaching Procedure
tively Coupled Plasma Atomic Emission Spectrometry
(ICP-AES), Flame Atomic Absorption Spectrometry JCGM 100Evaluation of Measurement Data – Guide to the
Expression of Uncertainty in Measurement
(FAAS), or Graphite Furnace Atomic Absorption Spec-
trometry (GFAAS) Techniques (Withdrawn 2021)
3. Terminology
E1644Practice for Hot Plate Digestion of Dust Wipe
3.1 For definitions of pertinent terms not listed here, see
Samples for the Determination of Lead
Terminologies D1356, E631, and E1605.
E1645Practice for Preparation of Dried Paint Samples by
Hotplate or Microwave Digestion for Subsequent Lead
3.2 Definitions:
Analysis
3.2.1 atomic emission, n—characteristic radiation emitted
E1726Practice for Preparation of Soil Samples by Hotplate
by an electronically excited atomic species.
Digestion for Subsequent Lead Analysis
3.2.1.1 Discussion—In atomic (or optical) emission
E1727Practice for Field Collection of Soil Samples for
spectrometry, a very high-temperature environment, such as a
Subsequent Lead Determination
plasma, is used to create excited state atoms. For analytical
E1728PracticeforCollectionofSettledDustSamplesUsing
purposes,characteristicemissionsignalsfromelementsintheir
Wipe Sampling Methods for Subsequent Lead Determi-
excited states are then measured at specific wavelengths.
nation
3.2.2 axial plasma, n—a horizontal inductively coupled
E1729Practice for Field Collection of Dried Paint Samples
plasma that is viewed end-on (versus radially; see 3.2.27).
for Subsequent Lead Determination
3.2.3 background correction, n—the process of correcting
E1792Specification for Wipe Sampling Materials for Lead
theintensityatananalyticalwavelengthfortheintensitydueto
in Surface Dust
the underlying spectral background of a blank. ISO 15202
E1908PracticeforSampleSelectionofDebrisWastefroma
3.2.4 background equivalent concentration, n—the concen-
Building Renovation or LeadAbatement Project for Tox-
tration of a solution that results in an emission signal of
icity Characteristic Leaching Procedure (TCLP) Testing
equivalent intensity to the background emission signal at the
for Leachable Lead (Pb)
analytical wavelength. ISO 15202
E1979Practice for Ultrasonic Extraction of Paint, Dust,
3.2.5 batch, n—a group of field or quality control (QC)
Soil, and Air Samples for Subsequent Determination of
samples that are collected or processed together at the same
Lead
time using the same reagents and equipment. E1613
E2115Guide for Conducting Lead Hazard Assessments of
Dwellings and of Other Child-Occupied Facilities
3.2.6 blank solution, n—solution prepared by taking a re-
E2271/E2271MPractice for Clearance Examinations Fol-
agent blank or field blank through the same procedure used for
lowing Lead Hazard Reduction Activities in Multifamily
sample dissolution.
Dwellings
3.2.7 calibration blank solution, n—calibrationsolutionpre-
E2913/E2913MPractice for Hotplate Digestion of Lead
pared without the addition of any stock standard solution or
from Composited Wipe Samples
working standard solution. ISO 15202
E2914/E2914MPractice for Ultrasonic Extraction of Lead
3.2.7.1 Discussion—The concentration of the analyte(s) of
from Composited Wipe Samples
interest in the calibration blank solution is taken to be zero.
E3074/E3074MPractice for Clearance Examinations Fol-
3.2.8 calibration solution, n—solution prepared by dilution
lowing Lead Hazard Reduction Activities in Single Fam-
of the stock standard solution(s) or working standard
ily Dwellings, in Individual Units of Multifamily
solution(s), containing the analyte(s) of interest at the concen-
Dwellings, and in Other Child-Occupied Facilities
tration(s) suitable for use in calibration of the analytical
2.2 ISO and European Standards:
instrument. ISO 15202
ISO 1042Laboratory glassware – One-mark volumetric
3.2.8.1 Discussion—The technique of matrix matching is
flasks
normally used when preparing calibration solutions.
ISO 3585Borosilicate glass 3.3 – Properties
3.2.9 continuing calibration blank (CCB), n—a solution
ISO 8655Piston-operated volumetric apparatus (6 Parts)
containing no analyte added, that is used to verify blank
ISO 15202Workplace air – Determination of metals and
response and freedom from carryover. E1613
metalloids in airborne particulate matter by inductively
3.2.9.1 Discussion—The absolute value of the measured
coupled plasma atomic emission spectrometry (3 Parts)
concentration of the CCB is to be not more than 50 % of the
ISO/IEC 17025General requirements for the competence of
lowest regulatory limit for the sample matrix analyzed or
testing and calibration laboratories
minimum level of concern.
AvailablefromUnitedStatesEnvironmentalProtectionAgency(EPA),William
The last approved version of this historical standard is referenced on Jefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460,
www.astm.org. http://www.epa.gov.
4 6
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St., Available from Bureau International des Poids et Mesures (BIPM), Pavillon de
4th Floor, New York, NY 10036, http://www.ansi.org. Breteuil F-92312, Sèvres Cedex, France, http://www.bipm.org.
E3203 − 21
3.2.10 excitation interferences, n—non-spectral interfer- 3.2.21 load coil, n—a length of metal tubing (typically
ences that manifest as a change in sensitivity due to a change copper) which is wound around the end of an inductively
in inductively coupled plasma conditions when the matrix of a coupled plasma torch and connected to the radio frequency
calibration or test solution is introduced into the plasma. generator. ISO 15202
ISO 15202
3.2.21.1 Discussion—The load coil is used to inductively
coupleenergyfromtheradiofrequencygeneratortotheplasma
3.2.11 field blank, n—sampling media (for example, a sam-
discharge.
pling wipe) that is exposed to the same handling as field
3.2.22 matrix interference, n—interferenceofanon-spectral
samples, except that no sample is collected (that is, no surface
is wipe sampled). D6785 nature which is caused by the sample matrix.
3.2.11.1 Discussion—Analysisresultsfromfieldblankspro- 3.2.22.1 Discussion—Matrix matching involves preparing
calibration solutions in which the concentrations of acids and
vide information on the analyte background level in the
sampling media, combined with the potential contamination other major solvents and solutes are matched with those in the
test solutions. ISO 15202
experienced by samples collected within the batch resulting
from handling.
3.2.23 method quantitation limit (MQL), n—the minimum
concentration of an analyte that can be measured with accept-
3.2.12 inductively coupled plasma (ICP), n—a high-
able precision, ordinarily taken to be at least ten times the
temperature discharge generated by a flowing conductive gas,
standard deviation of the mean blank signal (1).
normallyargon,throughamagneticfieldinducedbyaloadcoil
3.2.23.1 Discussion—The MQL is also known as the limit
that surrounds the tubes carrying the gas. ISO 15202
of quantitation.
3.2.13 inductively coupled plasma (ICP) torch, n—a device
3.2.24 nebulizer, n—a device used to create an aerosol from
consisting of three concentric tubes, the outer two usually
a liquid. ISO 15202
madefromquartz,thatisusedtosupportandintroducesample
into an ICP discharge. ISO 15202
3.2.25 outer (plasma) argon flow, n—the flow of argon gas
thatiscontainedbetweentheouterandintermediatetubesofan
3.2.14 injector tube, n—theinnermosttubeofaninductively
inductively coupled plasma torch.
coupled plasma torch, usually made of quartz or ceramic
materials, through which the sample aerosol is introduced to
3.2.25.1 Discussion—Typically 7 to 15 L/min. ISO 15202
the plasma. ISO 15202
3.2.26 pneumatic nebulizer, n—a nebulizer that uses high-
3.2.15 inner (nebulizer) argon flow, n—the flow of argon
speed gas flows to create an aerosol from a liquid. ISO 15202
gasthatisdirectedthroughthenebulizerandcarriesthesample
3.2.27 radial plasma, n—aninductivelycoupledplasmathat
aerosol through the injector and into the plasma.
is viewed from the side (versus axial).
3.2.15.1 Discussion—Typically 0.5to2 L/min. ISO 15202
3.2.28 sample dissolution, n—the process of obtaining a
3.2.16 instrumental detection limit (IDL), n—the lowest
solution containing the analyte(s) of interest from a sample.
concentration at which the instrumentation can distinguish
This may or may not involve complete dissolution of the
analyte content from the background generated by a minimal
sample. D6785
matrix. E1613
3.2.29 sample preparation, n—all operations carried out on
3.2.16.1 Discussion—The IDL pertains to the maximum
a sample, after transportation and storage, to prepare it for
capabilityofaninstrumentandshouldnotbeconfusedwiththe
analysis, including transformation of the sample into a mea-
method detection limit (MDL).
surable state, where necessary.
3.2.17 interelement correction, n—a spectral interference
3.2.30 spectral interference, n—an interference caused by
correction technique in which emission contributions from
the emission from a species other than the analyte of interest.
interfering elements that emit radiation at the analyte wave-
ISO 15202
length are subtracted from the apparent analyte emission after
3.2.31 spray chamber, n—a device placed between a nebu-
measuring the interfering element concentrations at other
lizer and an inductively coupled plasma torch whose function
wavelengths. ISO 15202
istoseparateoutaerosoldropletsinaccordancewiththeirsize,
3.2.18 intermediate (auxiliary) argon flow, n—the flow of
so that only very fine droplets pass into the plasma, and large
argongasthatiscontainedbetweentheintermediateandcenter
droplets are drained or pumped to waste. ISO 15202
(injector) tubes of an inductively coupled plasma torch.
3.2.32 stock standard solution, n—solution used for prepa-
3.2.18.1 Discussion—Typically 0.1to2 L/min. ISO 15202
ration of working standard solutions and/or calibration
3.2.19 internal standard, n—a non-analyte element, present
solutions, containing the analyte(s) of interest at a certified
in all calibration, blank, and sample solutions, the signal from
concentration(s) traceable to primary standards (National In-
which is used to correct for non-spectral interference or
stitute of Standards and Technology (NIST) or international
improve analytical precision. ISO 15202
measurement standards).
3.2.20 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.
E3203 − 21
3.2.33 transport interference, n—non-spectral interference 7.1.1 Laboratory Detergent, suitable for cleaning of labora-
caused by a difference in viscosity, surface tension, or density tory ware.
between the calibration and test solutions (for example, due to
7.2 Laboratory Apparatus for Analysis—Originallaboratory
differences in dissolved solids content, type and concentration
apparatus are not listed, but are assumed to be present.
of acid, and so forth). ISO 15202
7.2.1 Disposable Gloves, impermeable and powder-free, to
3.2.33.1 Discussion—Such differences produce a change in
avoidthepossibilityofcontaminationandtoprotectthemfrom
nebulizer efficiency and hence in the amount of analyte
contact with toxic and corrosive substances. PVC gloves are
reaching the plasma.
suitable.
3.2.34 ultrasonic nebulizer, n—a nebulizer in which the
7.2.2 Glassware, beakers and volumetric flasks complying
aerosol is created by flowing a liquid across a surface that is
with the requirements of ISO1042, made of borosilicate glass
oscillating at an ultrasonic frequency. ISO 15202
complying with the requirements of ISO3585.
7.2.3 Flat-Tipped Forceps, for unloading filters from sam-
3.2.35 viewing height (for a radial plasma), n—the position
plers or from filter transport cassettes.
in a radial plasma from where the emission measured origi-
7.2.4 Piston-Operated Volumetric Pipettors and Dispensers,
nates;generallygivenasthedistance,inmillimetres,abovethe
complying with the requirements of ISO8655, for pipetting
load coil. ISO 15202
and dispensing of leach solutions, acids, standard solutions,
3.2.36 x-y centering (for an axial plasma), v—horizontal
and so forth.
and vertical adjustment of an axial plasma to establish optimal
7.2.5 Plastic Bottles, 1-L capacity, with leak-proof screw
viewing conditions, such that only emission from the central
cap.
channel of the plasma is measured. ISO 15202
7.2.6 Inductively Coupled Plasma-Optical Emission
Spectrometer, computer-controlled, equipped with an auto-
4. Summary of Test Method
sampler.
4.1 Test solutions prepared from the sample solutions after
sample dissolution using Practices E1644, E1645, E1726,
8. Reagents
E1979,E2913/E2913M,orE2914/E2914Mareanalyzedusing
8.1 Purity of Reagents—Reagent grade chemicals shall be
inductively coupled plasma-optical emission spectrometry
used in all tests. Unless otherwise indicated, it is intended that
(ICP-OES) to determine the concentration of lead.
all reagents shall conform to the specifications of the Commit-
tee onAnalytical Reagents of theAmerican Chemical Society,
5. Significance and Use
where such specifications are available. Other grades may be
5.1 Thistestmethodisintendedforusewithotherstandards
used, provided that it can be demonstrated that they are of
thataddressthecollectionandpreparationofsamples(dustsby
sufficiently high purity to permit their use without decreasing
wipe, dried paint chips, and soils) that are obtained during the
the accuracy of the determinations.
assessment or mitigation of lead hazards from buildings and
8.2 Purity of Water—Unless otherwise indicated, reference
related structures.
to water shall be understood to mean Type II reagent water
5.2 Laboratories analyzing samples obtained during the
conforming to Specification D1193.
assessment or mitigation of lead hazards from buildings and
8.3 Nitric Acid (HNO ), concentrated, ρ ~1.42 g⁄mL
related structures shall conform to Practice E1583, or shall be
(~70% m/m).
recognized for lead analysis as promulgated by authorities
8.4 Nitric Acid (HNO ), diluted 1+9 (10%v⁄v). Carefully
having jurisdiction, or both. 3
and slowly begin adding 50mL of concentrated nitric acid to
NOTE 1—In the United States of America, laboratories performing
450mL of water.
analysis of samples collected during lead-based paint activities are
required to be accredited to ISO/IEC 17025 and to other requirements
8.5 Hydrochloric Acid(HCl), concentrated, ρ~1.18 g⁄mL
promulgated by the Environmental Protection Agency (EPA).
(~36% m/m).
5.3 This test method may also be used to analyze similar
8.6 Hydrochloric Acid Leach Solution, 0.1M.
samples from other environments such as toxic characteristic
extracts of waste sampled using Guide E1908 as prepared for
9. Equipment Preparation
analysis using EPA SW-846 Test Method 1311.
9.1 Wash glassware and plastic equipment with laboratory
detergent, rinse with tap water, soak for at least 4 hours in
6. Interferences
volume fraction 35 % nitric acid and water, rinse three times
6.1 For measurements made using the analytical wave-
withASTMTypeIWater,andallowtodrypreferablyinafume
lengths selected, no spectral interferences were observed, and
thus interference correction was not found to be necessary.
However, it is important to determine whether interference
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
correction is necessary under the test conditions used.
Standard-Grade Reference Materials, American Chemical Society, Washington,
DC. For suggestions on the testing of reagents not listed by theAmerican Chemical
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
7. Apparatus and Materials
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
7.1 Argon, suitable for use in ICP-OES. copeial Convention, Inc. (USPC), Rockville, MD.
E3203 − 21
hood. Commercial, automatic systems are available that per- a calibration blank solution. During preparation of calibration
form a similar process. solutions, add reagents (for example, acids), as required, to
matrix-match the calibration solutions with the test solutions.
9.2 Alternatively, soak glassware and plastic equipment in
12.1.3.2 Store working standard solutions in suitable
volume/volume 1+1 nitric acid and water in a plastic tub
containers, such as 1-L polypropylene bottles, for a maximum
preferably in a working hood with the hood sash down, rinse
period of one month.
three times with ASTM Type I Water, and allowed to dry
preferably in a fume hood.
NOTE 2—The shelf life of stock standard and working standard
solutions may be extended if they are demonstrated, by comparison with
calibration verification solutions, to be acceptable.
10. Safety Procedures
NOTE 3—The type(s) and volume(s) of reagents required to matrix
10.1 Hazards to personnel exist in the operation of the
match the calibration and test solutions will depend on the sample
dissolution method used.
ICP-OES. Do not operate any ICP-OES unit until the manu-
facturer’s instruction manual has been read and completely
12.2 Internal Standard Stock Solutions—If required, use
understood.Followallsafetyinstructionsinthemanualandthe
standard stock solutions to prepare test solutions that contain
safetyrequirementspertainingtothehandling,storage,anduse
the internal standard element(s). The internal standard ele-
of compressed gases.
ment(s) shall be compatible with the test solution matrix, and
the matrix of the internal standard stock solution shall be
10.2 Hazards to personnel exist in all operations in which
compatible with the analyte metals and metalloids of interest.
hot, concentrated mineral acids are used. The appropriate
Observe the manufacturer’s expiration date or recommended
laboratory procedures for working with reagents of this nature
shelf life.
shall be observed.
NOTE 4—Internal standard solutions may be used to correct for
10.3 Lead and lead compounds are hazardous to health and
instrument drift and physical interferences. Internal standard solutions are
shall be handled in a manner consistent with the danger they
usually single-element standard stock solutions, which are commercially
present.
available or can be prepared from high-purity metals and metalloids or
their salts.
10.4 The instrument exhaust gases are toxic, corrosive
NOTE 5—Internal standards, if utilized, should be added to blanks,
vapors. The instrument exhaust gases shall be mechanically
samples, and standards in a like manner. Internal standards may be added
exhausted from the laboratory (see instrument manufacturer’s
to each test solution during the sample preparation process or,
instructions).
alternatively, by use of an on-line internal standard addition system.
12.2.1 Interference Check Solutions—If interelement cor-
11. Sampling Collection and Preparation
rection is to be carried out, use a stock standard solution to
11.1 Sample Collection—Collect samples, as appropriate to
prepare an interference check solution by serial dilution for
the matrix of interest, using Practices D6966, E1727, E1728,
eachinterferenttoattainasuitableconcentration(forexample,
E1729, E2271/E2271M,or E3074/E3074M, or combinations
between 50and 200mg⁄L). If appropriate, matrix match the
thereof.
interference check solutions and test solutions. Store interfer-
ence check solutions in suitable containers, such as 1-L
11.2 Sample Preparation—Prepare samples for analysis, as
polypropylene bottles, for a maximum period of one month.
appropriate to the matrix of interest, using Practices E1644,
E1645, E1726, E1979, E2913/E2913M,or E2914/E2914M.
12.3 The run order of standards and client samples per
matrix of interest is shown as Table 1. Frequency and accep-
12. Calibration and Standardization
tance limits for standards are also shown.
12.1 To prepare stock standard solutions, use commercial
13. Procedure
single-element or multi-element standard solutions with certi-
fied concentrations traceable to primary standards (NIST or
13.1 Method Optimization:
international measurement standards). Observe the manufac-
13.1.1 General Guidance—Optimize the test method and
turer’s expiration date or recommended shelf life.
validate the performance of the method for analysis of test
12.1.1 Alternatively, prepare stock standard solutions from
solutions in accordance with the performance criteria provided
lead or lead salts. The procedure used to prepare the solutions
in this test method, or specified customer requirements, or
shall be fit for purpose, and the calibration of any apparatus
both, using sample solutions prepared as described in Section
used shall be traceable to primary standards. The maximum
11 of this test method, which is suitable for use with the
recommended shelf life is one year from date of initial
available ICP-OES instrument(s). Use the default instrument
preparation.
conditions given by the manufacturer as a starting point in the
12.1.2 Store stock standard solutions in suitable containers,
method development process. Refer to guidance on ICP-OES
such as 1-L polypropylene bottles.
method development available in textbooks, instrument
12.1.3 Calibration Solutions:
manuals, and standards.
12.1.3.1 Fromthestockstandardsolutions,prepareworking
NOTE 6—ICP-OES analysis applies to a wide range of instruments, for
standardsolutionsbyserialdilutions;theseshallincludeallthe
example, simultaneous or sequential instruments with photomultiplier or
metals and metalloids of interest at suitable concentrations
solid state detection systems. Each of these different types of instruments
(typically between 0.05and 100mg⁄L, depending on the
needs to be set up and operated in a different manner. There are some
sensitivity of the emission lines to be measured).Also prepare principlesthatapplytothedevelopmentofmethodforallinstruments,but
E3203 − 21
TABLE 1 ICP-OES Run Order with Frequency and Acceptance Limits for Standards
Name Use Specification
Calibration Standards Instrument calibration Must be matrix matched to digestates/extracts.
Must be measured prior to measuring any sample
digestates or extracts.
Correlation coefficient of$0.995, as measured using linear
regression on instrument response versus concentration.
Must include a blank solution.
Independent Calibration Verification Once per day after calibration Mid-range calibration standard must be measured after
(ICV) calibration; measured value within ±10 % of known value.
Initial Calibration Blank (ICB) Once per run at the beginning of the run Absolute value not more than 50 % of the lowest regulatory
limit for the sample matrix analyzed or minimum level of
concern.
Interference Check Sample (ICS) At the beginning and end of each run or twice every 12 h Within 20 % of known value.
Sample Analysis N/A Samples exceeding the calibration range should be diluted
and rerun.
Continuing Calibration Verification (CCV) At the end of a sample run, as well as every 12 h, or Within ±20 % of known value.
according to instrument manufacturer’s recommendations,
or according to instrument Performance Characteristic
Sheet (PCS), or at a predetermined Standard Operating
Procedure (SOP) frequency, whichever is most frequent.
Continuing Calibration Blank (CCB) After each ICS and CCV Absolute value not more than 50 % of the lowest regulatory
limit for the sample matrix analyzed or minimum level of
concern.
there are also many parameters that are only applicable to particular possible,byselectinganalternativeanalyticalwavelengththatisfreefrom
instruments or types of instruments. or less prone to interference. Also, for some measurement tasks, there
might be a need to obtain quantitative measurements at concentrations
13.1.2 Quantitation Limit—An instrumental measurement
below 0.1× the limit value.
value that is used to provide a lower concentration limit for
13.1.4 Axial or Radial Viewing of the Plasma—If an instru-
reporting quantitative analysis data for a given analytical
ment with an axial ICP torch and an instrument with a radial
method.
ICP torch are both available (or if a dual-view instrument is
NOTE 7—Any sample that generates a lead measurement below the
available), decide which orientation is best suited to the
quantitation limit is reported as a less-than value using the quantitation
measurement task. It might be that it is best to use an axial
limit value multiplied by the appropriate dilution factors resulting from
plasmatomakemeasurementsatsomeanalyticalwavelengths,
preparation of the sample for instrumental analysis.
whilearadialplasmamaybebettersuitedformeasurementsat
13.1.3 Spectral Interferences—Give consideration to the
other wavelengths.
significance of any known spectral interferences in the context
of the measurement task. For each potentially useful analytical
NOTE 9—Axial viewing of the plasma might be necessary to obtain the
necessary quantification limits, but it is more susceptible than radial
wavelength, refer to published information, and consider the
viewing to spectral interferences.
relationship between the magnitude of interferences and the
relative exposure limits of the interferents and elements to be
13.1.5 Sample Introduction System—Decide on the type of
determined. For example, if the measurement task entails
sample introduction system to use. Take into consideration the
testing compliance with exposure limit values, an interferent
requiredsensitivityandthenatureofthetestsolutionmatrix.In
present at 10× its limit value will cause a positive bias of
most cases, the system supplied by the instrument manufac-
>10% if:
turer will be adequate.
@10 3 ~LV ⁄ LV ! 3 ~ρ ⁄ 1000!#.0.1 (1)
a i a NOTE 10—Ultrasonic nebulizers give higher sensitivity than conven-
tional pneumatic nebulizers. However, they are less corrosion-resistant.
where:
For instance, if test solutions contain hydrofluoric acid, it will be
LV = limit value, in mg/m , of the analyte,
necessary to use a corrosion-resistant sample introduction system.
a
LV = limit value, in mg/m , of the interferent, and
i
13.1.6 Analytical Wavelengths—Select one or more emis-
ρ = apparentanalyteconcentration,inmg/L,causedbyan
a
sion lines on which to make measurements for lead, utilizing
interferent concentration of 1000 mg/L.
wavelength tables available in the literature (2). Take into
If the sum of all potential interferences is greater than 0.1×
consideration the wavelengths that are accessible on the
the limit value of the analyte when each of the interferents is
instrument and recommended by the instrument manufacturer.
present at 10× its limit value, use an alternative analytical
Also take into consideration the background equivalent
wavelength or apply interelement corrections.
concentrations, the required quantitation limits, and spectral
interferences that could be significant at each wavelength.
NOTE 8—Interelement correction is not normally necessary for mea-
surements made to test compliance with limit values. It is best avoided, if Ordinarily the more sensitive emission lines will be most
E3203 − 21
favorable, but it is necessary to avoid the use of wavelengths analyte in the plasma. The longer the residence time, the
where there is spectral overlap or significant background greater the likelihood of the analyte to be atomized, excited,
and ionized.
interference.
NOTE 15—For an element that emits strong ionic lines and has a high
NOTE 11—Scanning, sequential, monochromator-based instruments
ionization potential, a long residence time is desired. Hence a lower
enable measurements over the entire ultraviolet/visible spectrum. Grating
nebulizer argon flow rate could be used to obtain higher sensitivity for
instruments and instruments with solid state detectors also allow for a
such an element (provided that the nebulizer efficiency does not fall off
widespectralrange.However,simultaneous,conventionalpolychromator-
significantly when the flow rate is reduced). On the other hand, for
based instruments are more limited in that users can only select from the
elementsthatemitstrongatomiclinesandareeasilyionized,afasterflow
analytical lines that are available given a particular instrument configu-
ratecouldbeusedsothattheatomsarenotionizedbeforeexcitationtakes
ration. If available, it is advisable to use more than one emission line for
place.
leadtocheckforanyproblemsnotidentifiedduringmethoddevelopment.
13.1.9.2 Radiofrequency (RF) Power—Under normal
13.1.7 Background Correction—Generate a spectral scan
circumstances, use the default RF power recommended by the
for each of the candidate analytical wavelengths while analyz-
instrument manufacturer. However, the RF power may be
ing (1) a blank solution, (2) a calibration solution, and (3)a
optimized for specific applications.
typical test solution into the plasma. Examine the line profiles
NOTE 16—The RF power applied to the plasma can be optimized in
and select points at which to make background correction
accordance with need. The more RF power that is applied to the plasma,
measurements. Where applicable, make measurements at a
the hotter it gets.
single point to correct for a simple background shift, that is, a
13.1.9.3 Viewing Height (Radial Plasma)—Under normal
shift in background intensity that is essentially constant over a
circumstances, use the default viewing height setting recom-
given range (for example, 0.5nm) on either side of the analyte
mendedbytheinstrumentmanufacturer.However,theviewing
emission line. Alternatively, for a sloping background, make
height may be optimized for specific applications.
measurements at two points to correct for the non-constant
background shift. Many software packages for ICP-OES in-
NOTE 17—The viewing height can be optimized for a selected analyte
line or lines. This is because different regions of the plasma are
struments have automatic background correction with varying
characterized by different temperatures, and each analytical wavelength
algorithms.
has an optimum temperature at which its emission line is most intense.
NOTE 12—Different instrument types use different means of making
13.1.10 Instrument Operating Parameters—Refer to the
off-peakbackgroundcorrectionmeasurements.Insomeinstruments(such
instrument manufacturer’s instructions and determine the op-
as those using monochromators or polychromators), the analyte intensity
timum settings for other relevant instrument operating param-
is measured first, and then separate measurements are made at the
eters(forexample,detectorpower,integrationtime,numberof
wavelengths used for background correction. However, grating instru-
ments with solid-state detectors measure analyte and background signals
integrations, and so forth).
simultaneously. Measurements employing simultaneous background cor-
13.1.11 Sample Introduction Rate—Under normal
rectionreducenoiseduetosampleintroduction,andtheyarefastsinceno
circumstances,usethesampleuptakeraterecommendedbythe
additional analysis time is required to make off-peak measurements.
nebulizer manufacturer. However, the uptake rate may be
NOTE13—SomeICP-OESsoftwarefeaturestheuseofchemometricsto
optimized to achieve a suitable compromise between signal
automatically select parameters such as background correction points.
Also,softwarecanbeusedtoperformintelligentoptimizationstudieswith intensity and uptake rate
minimal user interaction.
13.1.12 Sample Wash-Out Parameters—Use a suitable
wash-out solution, wash-out time, wash-out rate, and read
13.1.8 Interelement Correction—If the only analytical
delay. Conduct tests to ensure that there is no significant
wavelength(s) chosen suffer(s) from spectral overlap or com-
carryover of analyte between measurements.
plex background shift, consider the need to apply interelement
13.1.13 Calibration Solutions:
correction.Ifthisisnecessary,generateandapplyinterelement
13.1.13.1 Matrix Matching—Unless an internal standard is
correction factors. Alternatively, if the necessary software is
used, match the matrix of the calibration solutions with that of
available, use a chemometric technique (such as multicompo-
the test solutions.
nent spectral fitting) to perform interelement correction.
NOTE 18—Even if an internal standard is used, it is recommended that
NOTE 14—Interelement correction factors can be generated from the
matrixmatchingisalsocarriedout.Ingeneral,itispreferabletomatchthe
apparent analyte concentrations obtained by analyzing individual, spec-
matrix of the calibration and test solutions, rather than rely on the use of
trally pure test solutions containing high concentrations (for example,
internal standards to correct for transport and excitation interferences.
1000mg⁄L) of interfering elements.Alternatively, if calibration solutions
13.1.13.2 Calibration Range—Carry out experiments to de-
contain varied concentrations of the analyte and interfering element(s),
data handling software of some instruments may be used to calculate and
termine the linear dynamic range for each of the selected
apply interference corrections automatically.
analytical wavelengths under the intended operating condi-
tions.Thenselectarangeofanalyteconcentrationsoverwhich
13.1.9 Plasma Conditions:
to prepare the calibration solutions.
13.1.9.1 Gas Flows—Under normal conditions, use the
default gas flows recommended by the instrument manufac-
NOTE19—Ifmorethanoneanalyticalwavelengthistobeused,thiswill
need to be taken into consideration when selecting the range of concen-
turer for inner, intermediate, and outer argon flows. However,
trations to be covered.
if desired, the nebulizer (inner) argon flow may be optimized
for specific applications. The nebulizer argon flow can be
13.1.14 Internal Standards—Decide whether to use (an)
critical because it largely determines the residence time of the internal standard(s) to correct for non-spectral interferences or
E3203 − 21
to improve precision. Carefully select internal standard emis- 13.3.4 Analysis:
sion lines to ensure that they are suitable for the intended 13.3.4.1 Aspiratethecalibrationsolutionsintotheplasmain
purpose, and exhibit adequate sensitivity. Ensure that internal orderofincreasingconcentration,andmakeemissionmeasure-
standardelementsarenotpresentinthetestsolutions,andalso mentsforeachsolution.Generateacalibrationfunctionforthe
ensure that the standard solutions for addition of internal metals and metalloids of interest, preferably using linear
standards are chemically compatible with the test solution regression via the instrument’s computer. It is recommended
matrix (that is, they must not cause precipitation). thattheemissionintensityofthecalibrationblankissubtracted
for emission intensities of other calibration solutions, and that
NOTE 20—A single internal standard may be used to correct for
thecalibrationfunctionisforcedthroughtheorigin.Repeatthe
transport interferences that arise from a matrix mismatch between the
calibration if the correlation of determination (r) for any of the
calibration and test solutions, and for changes in nebulizer efficiency that
can occur during analysis. Internal standards may also be used to correct
elements of interest is <0.995.
forexcitationinterferencesthatarisefromamatrixmismatchbetweenthe
NOTE 23—If r < 0.995, it might be possible to remove an erroneous
calibrationandtestsolutionsandforchangesinplasmaconditionsthatcan
calibrationpoint(forexample,byusinganoutliertest),andthenreprocess
occur during analysis as a result of fluctuations in power or gas flows, or
the data to obtain acceptable calibration. However, the minimum number
both. Multiple internal standards need to be used, and the wavelengths at
of calibration solutions prescribed should be maintained.
which they are measured need to be carefully selected, so that the
characteristics of the analyte emission lines closely match those of the
13.3.4.2 Aspirate the laboratory blank solutions and the test
internal standard emission lines. Use of internal standards can also
solutions into the plasma, and make emission measurements
improveanalyticalprecisionforsimultaneousinstrumentsbyreducingthe
for each solution. Use the calibration function to determine the
effect of noise associated with sample introduction.
concentrations of metals and metalloids of interest.
13.2 Instrument Performance Checks:
13.3.4.3 Analyze the calibration blank and mid-range cali-
13.2.1 Visual Inspection—The user shall perform regular
bration solutions after the initial calibration, and then after (at
visual checks to ensure that the instrument and ancillaries are
least) every twenty test solutions. If the measured concentra-
ingoodorderbeforecommencingwork.Followtheinstrument
tion of an element of interest in the continuing calibration
manufacturer’s recommendations. Further guidance is given in
blank (CCB) is above its method detection limit, take one of
Appendix X1.
the following corrective measures. Either use the instrument
13.2.2 Performance Checks and Fault Diagnostics—The
softwaretocorrectfortheobservedsensitivitychange(reslope
user shall carry out performance checks daily to verify that the
facility), or suspend analysis and recalibrate the spectrometer.
ICP-OES instrument is operating in accordance with specifi-
In either case, reanalyze the test solutions that were analyzed
cations. More rigorous fault diagnostics shall be used if it is
during the period in which the sensitivity change occurred, or
suspected that the instrument is not functioning properly.
reprocess the data to account for the observed sensitivity
Follow the instrument manufacturer’s recommendations. Fur-
change.
ther guidance is given in Appendix X2.
13.3.4.4 If interelement correction is used, analyze interfer-
NOTE 21—A comprehensive series of performance checks has been
ence check solutions to verify that the interelement correction
described in the literature (3), and this can be used to supplement
procedure is effective at each of the analytical wavelengths
performancechecksandfaultdiagnosticsrecommendedbytheinstrument
concerned.
manufacturer.
13.3.4.5 Analyze quality control solutions at a minimum
13.3 Routine Analysis:
frequency of 1 per 20 test samples, and use the results to
13.3.1 Dilution of Sample Solutions—Perform any required
monitor the performance of the analytical procedure.
dilution of sample solutions prior to addition of internal
13.3.4.6 Examinetheprecision(relativestandarddeviation)
standards.
of all results, and repeat any analyses if the relative standard
13.3.2 Addition of Internal Standards—Ifusing(an)internal
deviation is unacceptably high.
standard(s), add the same concentration to all solutions to be
13.3.4.7 Iftheconcentrationofleadinasampletestsolution
measured (that is, calibration solutions, blank solutions, test
is found to be above the upper limit of the calibration range,
solutions, interference check solutions, and quality control
dilute the sample by an appropriate factor, matrix-match as
sample solutions).
necessary, and repeat the analysis (and account for the dilution
NOTE 22—Internal standards may be added by pipetting a known factor). Alternatively, use a suitable alternative analytical
volume of single-element stock standard solution into a known volume of
wavelength.
each solution to be measured. Alternatively, the solution to be measured
andasolutioncontaininginternalstandard(s)maybemixedduringsample
14. Calculations
introduction using a two-channel peristaltic pump, T-piece and mixing
coil.
14.1 Method Detection Limits and Quantitation Limits—
Method detection limits (MDLs) and method quantitation
13.3.3 Instrument Set-up—Set up the ICP-OES instrument
limits (MQLs) depend on a number of
...