ASTM D7202-22

Standard Test Method for Determination of Beryllium in the Workplace by Extraction and Optical Fluorescence Detection

SIGNIFICANCE AND USE
5.1 Exposure to beryllium can cause a potentially fatal disease, and occupational exposure limits for beryllium in air and on surfaces have been established to reduce exposure risks to potentially affected workers (4-7). Sampling and analytical methods for beryllium are needed in order to meet the challenges relating to exposure assessment and risk reduction. Sampling and analysis methods, such as the procedure described in this test method, are desired in order to facilitate on-site and fixed-site laboratory measurement of trace beryllium. Beryllium analysis results can then be used as a basis for exposure assessment and protection of human health.
SCOPE
1.1 This test method is intended for use in the determination of beryllium by sampling workplace air and surface dust.  
1.2 This test method assumes that air and surface samples are collected using appropriate and applicable ASTM International standard practices for sampling of workplace air and surface dust. These samples are typically collected using air filter sampling, vacuum sampling or wiping techniques. See Guide E1370 for guidance on air sampling strategies, and Guide D7659 for guidance on selection of surface sampling techniques.  
1.3 Determination of beryllium in soil is not within the scope of this test method. See Test Method D7458 for determination of beryllium in soil samples.  
1.4 This test method includes a procedure for extraction (dissolution) of beryllium in weakly acidic medium (pH of 1 % aqueous ammonium bifluoride is 4.8), followed by field analysis of aliquots of the extract solution using a beryllium-specific-optically fluorescent dye.  
1.5 The procedure is suitable for on-site use in the field for occupational and environmental hygiene monitoring purposes. The method is also applicable for use in fixed-site laboratories.  
1.6 No detailed operating instructions are provided because of differences among various makes and models of suitable fluorometric instruments. Instead, the analyst shall follow the instructions provided by the manufacturer of the particular instrument. This test method does not address comparative accuracy of different devices or the precision between instruments of the same make and model.  
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.8 This test method contains notes that are explanatory and not part of mandatory requirements of the standard.  
1.9 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.  
1.10 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.

General Information

• Status: Published
• Publication Date: 31-Aug-2022
• ICS: 13.040.30 - Workplace atmospheres
• Technical Committee: D22 - Air Quality
• Drafting Committee: D22.04 - Workplace Air Quality

Relations

• Refers: ASTM D1356-20a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Sep-2020
• Refers: ASTM D1356-20 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Mar-2020
• Refers: ASTM D7296-18 - Standard Practice for Collection of Settled Dust Samples Using Dry Wipe Sampling Methods for Subsequent Determination of Beryllium and Compounds
• Effective Date: 01-Nov-2018
• Refers: ASTM D6966-18 - Standard Practice for Collection of Settled Dust Samples Using Wipe Sampling Methods for Subsequent Determination of Metals
• Effective Date: 01-Nov-2018
• Refers: ASTM D4840-99(2018)e1 - Standard Guide for Sample Chain-of-Custody Procedures
• Effective Date: 15-Aug-2018
• Refers: ASTM E882-10(2016) - Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
• Effective Date: 01-Dec-2016
• Refers: ASTM E882-10(2016)e1 - Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
• Effective Date: 01-Dec-2016
• Refers: ASTM D1356-15a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Oct-2015
• Refers: ASTM D1356-15 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Jul-2015
• Refers: ASTM D1356-14b - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Dec-2014
• Refers: ASTM E177-14 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2014
• Refers: ASTM D1356-14a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-May-2014
• Refers: ASTM D1356-14 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Jan-2014
• Refers: ASTM E177-13 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013

Overview

ASTM D7202-22 is the Standard Test Method for Determination of Beryllium in the Workplace by Extraction and Optical Fluorescence Detection, published by ASTM International. This standard provides a systematic approach for detecting and quantifying beryllium in workplace air and surface dust. Owing to the toxicity of beryllium and the existence of strict occupational exposure limits, accurate and sensitive measurement methods are essential to safeguard worker health and support compliance with regulatory requirements. The standard is suitable for both on-site field use and analysis in fixed laboratory settings, addressing the diverse needs of occupational and environmental hygiene monitoring programs.

Key Topics

• Scope and Applicability

  • Designed for the determination of beryllium in workplace air and surface dust.
  • Not intended for beryllium determination in soil; see ASTM D7458 for soil analysis.
  • Assumes collection of samples via air filter, vacuum, or wipe sampling, following established ASTM sampling practices.

• Method Overview

  • Uses extraction (dissolution) of beryllium from collected particulate matter in a dilute, weakly acidic ammonium bifluoride solution.
  • Beryllium is then quantified by optical fluorescence using a beryllium-specific dye and measured with a fluorometer.

• Performance and Quality Control

  • Includes requirements for calibration standards and handling of blanks and spiked samples to ensure accuracy and account for potential contamination.
  • Provides guidance on control charts and the use of certified reference materials for quality assurance.
  • Specifies reporting requirements, including sample information and analytical parameters.

• Instrument Flexibility

  • Allows for the use of different makes and models of fluorometric instruments, emphasizing adherence to manufacturer instructions for instrument operation.
  • Calibration procedures and analytical calculations are outlined to support consistent results across laboratories.

• Health and Safety Considerations

  • Stresses the importance of appropriate safety, health, and environmental practices.
  • Users are responsible for establishing necessary safety protocols and considering regulatory constraints.

Applications

• Occupational Exposure Monitoring

  • Supports compliance with occupational exposure limits for airborne and surface beryllium.
  • Helps industrial hygienists and safety professionals assess worker exposure and determine the effectiveness of engineering controls or personal protective equipment.

• Environmental Hygiene Programs

  • Facilitates detection of trace beryllium for ongoing workplace environmental monitoring.
  • Enables both short-term, real-time decision-making on-site and comprehensive analysis in laboratory environments.

• Quality Assurance in Workplaces Handling Beryllium

  • Ensures that manufacturing, processing, or maintenance operations involving beryllium are conducted within safe atmospheric and surface concentrations.
  • Supports incident investigations and remediation by providing reliable quantification methods.

Related Standards

• ASTM D7035 - Test Method for Determination of Metals and Metalloids in Airborne Particulate Matter
• ASTM D6966, D7144, D7296 - Various practices for collection of surface dust, wipe, and vacuum sampling methods
• ASTM D7659 - Guide for Strategies for Surface Sampling of Metals and Metalloids
• ASTM D7458 - Test Method for Determination of Beryllium in Soil and Sediment
• ASTM E1370 - Guide for Air Sampling Strategies for Worker and Workplace Protection
• ASTM D4840 - Guide for Sample Chain-of-Custody Procedures
• ASTM D1193 - Specification for Reagent Water

Summary

ASTM D7202-22 is a vital standard for occupational hygiene, providing a robust method for extracting and quantifying beryllium in workplace environments. Its flexible application in both field and laboratory settings makes it a key tool for exposure risk assessment, regulatory compliance, and the protection of worker health, particularly in industries where beryllium is processed or used. By following this standard, organizations help ensure that monitoring and reporting processes are accurate, consistent, and aligned with global best practices.

Standards Content (Sample)

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: D7202 − 22
Standard Test Method for
Determination of Beryllium in the Workplace by Extraction
and Optical Fluorescence Detection
This standard is issued under the fixed designation D7202; 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 1.9 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 Thistestmethodisintendedforuseinthedetermination
responsibility of the user of this standard to establish appro-
of beryllium by sampling workplace air and surface dust.
priate safety, health, and environmental practices and deter-
1.2 This test method assumes that air and surface samples
mine the applicability of regulatory limitations prior to use.
are collected using appropriate and applicable ASTM Interna-
1.10 This international standard was developed in accor-
tional standard practices for sampling of workplace air and
dance with internationally recognized principles on standard-
surface dust. These samples are typically collected using air
ization established in the Decision on Principles for the
filter sampling, vacuum sampling or wiping techniques. See
Development of International Standards, Guides and Recom-
Guide E1370 for guidance on air sampling strategies, and
mendations issued by the World Trade Organization Technical
Guide D7659 for guidance on selection of surface sampling
Barriers to Trade (TBT) Committee.
techniques.
2. Referenced Documents
1.3 Determination of beryllium in soil is not within the
scope of this test method. See Test Method D7458 for 2.1 ASTM Standards:
determination of beryllium in soil samples.
D1193Specification for Reagent Water
D1356Terminology Relating to Sampling and Analysis of
1.4 This test method includes a procedure for extraction
Atmospheres
(dissolution)ofberylliuminweaklyacidicmedium(pHof1%
D4840Guide for Sample Chain-of-Custody Procedures
aqueous ammonium bifluoride is 4.8), followed by field
D5337Practice for Flow RateAdjustment of Personal Sam-
analysis of aliquots of the extract solution using a beryllium-
pling Pumps
specific-optically fluorescent dye.
D6966Practice for Collection of Settled Dust Samples
1.5 The procedure is suitable for on-site use in the field for
Using Wipe Sampling Methods for Subsequent Determi-
occupational and environmental hygiene monitoring purposes.
nation of Metals
Themethodisalsoapplicableforuseinfixed-sitelaboratories.
D7035Test Method for Determination of Metals and Met-
1.6 No detailed operating instructions are provided because alloids in Airborne Particulate Matter by Inductively
of differences among various makes and models of suitable Coupled Plasma Atomic Emission Spectrometry (ICP-
fluorometric instruments. Instead, the analyst shall follow the AES)
instructions provided by the manufacturer of the particular D7144Practice for Collection of Surface Dust by Micro-
instrument. This test method does not address comparative vacuum Sampling for Subsequent Determination of Met-
accuracy of different devices or the precision between instru- als and Metalloids
ments of the same make and model. D7296Practice for Collection of Settled Dust Samples
Using Dry Wipe Sampling Methods for Subsequent De-
1.7 The values stated in SI units are to be regarded as
termination of Beryllium and Compounds
standard. No other units of measurement are included in this
D7458Test Method for Determination of Beryllium in Soil
standard.
and Sediment Using Ammonium Bifluoride Extraction
1.8 Thistestmethodcontainsnotesthatareexplanatoryand
and Fluorescence Detection
not part of mandatory requirements of the standard.
D7659Guide for Strategies for Surface Sampling of Metals
and Metalloids for Worker Protection
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, 2022. Published September 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2005. Last previous edition approved in 2021 as D7202–21. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D7202-22. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7202 − 22
D7707SpecificationforWipeSamplingMaterialsforBeryl- lium. Beryllium analysis results can then be used as a basis for
lium in Surface Dust exposure assessment and protection of human health.
D8358GuideforAssessmentandInclusionofWallDeposits
6. Interferences
in the Analysis of Single-Stage Samplers for Airborne
6.1 This test method is highly specific for beryllium. Other
Particulate Matter
solvated metal ions are either bound by ethylenediaminetet-
E177Practice for Use of the Terms Precision and Bias in
raacetic acid (EDTA) in the detection solution, or they precipi-
ASTM Test Methods
tate out due to the high alkalinity of the detection solution (1).
E691Practice for Conducting an Interlaboratory Study to
In case the sample is suspected of having fluorescent organic
Determine the Precision of a Test Method
contaminants that are suspected to be present, then their
E882Guide for Accountability and Quality Control in the
presence can be checked and removed (8).
Chemical Analysis Laboratory
E1154Specification for Piston or Plunger Operated Volu-
6.2 If the samples are suspected of having a contaminant
metric Apparatus
that fluoresces and has excitation and emission spectra that
E1370Guide for Air Sampling Strategies for Worker and
overlap with that of the signal produced by the fluorescent dye
Workplace Protection
bound to beryllium, then this contaminant needs to be re-
moved.The presence of such a contaminant can be verified by
3. Terminology
subjecting the filtered sample to fluorescence excitation after
3.1 Definitions—Fordefinitionsoftermsnotappearinghere, the extraction step (without adding the fluorescent dye). If a
see Terminology D1356. fluorescence signal is detected, then that signal is ascribed to
the presence of a fluorescent contaminant. To remove the
3.2 Definitions of Terms Specific to This Standard:
contaminant, high-purity activated charcoal is added to the
3.2.1 wipe sample, n—sample collected by wiping a repre-
beryllium extraction solution and the extraction procedure is
sentative surface of known area, as determined by Practice
carried out at elevated temperature (80 to 90°C for at least 45
D6966,orequivalentmethod,withanacceptablewipematerial
minutes). If the beryllium extraction procedure has already
as defined in Specification D7707.
been performed, then after the addition of activated charcoal,
the extraction process is repeated at the elevated temperature.
4. Summary of Test Method
The solution is filtered to remove the activated charcoal before
4.1 Particles potentially containing beryllium from work-
making the measurement solution. The measurement solution
place air or surfaces, or both, are collected in the field using
is made by the addition of the fluorescent dye solution to an
procedures described in ASTM International standards. To
aliquot of the extraction solution. Details of this process have
extract (or dissolve) beryllium in the collected samples, the
been published (8).
media in or on which the samples are collected (that is, air
6.3 If iron is present in high excess in the sample (typically
sample, vacuum sample or wipe) are treated using an acidic
more than 20 µM), the resulting measurement solution may
extraction solution containing dilute ammonium bifluoride,
appear golden-yellow. In this case the solution should be left
NHHF (1). The presence of active fluoride ions (HF by
for an hour or more for the iron to precipitate. The solution
dissociation of ammonium bifluoride in acidic medium) en-
should then be re-filtered using the same procedure as for
ables dissolution of refractory materials such as “high-fired”
filtering the dissolution solution (after the dissolution step),
beryllium oxide. The extraction solution produced from each
prior to fluorescence measurement.
sample is then filtered and an aliquot of this extract is added to
a pH-adjusted detection solution which contains a beryllium-
7. Apparatus
specific optical fluorescence reagent (1, 2). The fluorescence
7.1 Sampling Equipment:
exhibitedbythisfinalsolutionisthenmeasuredonacalibrated
7.1.1 Air Sampling—Useairsamplersandfiltersforcollect-
fluorometer to quantify the amount of beryllium in the sample
ing personal air samples as described in Test Method D7035
(3).
and Guide D8358.
7.1.2 Wipe Sampling—Use wipe sampling apparatus for
5. Significance and Use
collecting surface dust samples as described in Practice D6966
5.1 Exposure to beryllium can cause a potentially fatal
(or Practice D7296 in special cases), using wipes meeting the
disease, and occupational exposure limits for beryllium in air
specifications described in Specification D7707.
andonsurfaceshavebeenestablishedtoreduceexposurerisks
7.1.3 Vacuum Sampling—If wipe sampling is not advisable
to potentially affected workers (4-7). Sampling and analytical
for surface sample collection, use vacuum sampling apparatus
methods for beryllium are needed in order to meet the
for collecting surface dust samples as described in Practice
challenges relating to exposure assessment and risk reduction.
D7144.
Sampling and analysis methods, such as the procedure de-
7.2 Instrumentation:
scribed in this test method, are desired in order to facilitate
7.2.1 Ultraviolet/Visible (UV/Vis) Fluorometer, with irradi-
on-site and fixed-site laboratory measurement of trace beryl-
ance excitation lamp (excitation λ=380 nm) and time-
integrating visible detector (400–700 nm, λmax ≈ 475 nm).
7.2.2 Mechanical Agitator or Heating Source, shaker, rota-
The boldface numbers in parentheses refer to a list of references at the end of
this standard. tor or ultrasonic bath; or heat block, oven or heating bath.
D7202 − 22
NOTE 1—For routine samples, a shaker, rotator, or ultrasonic bath is
dye solution is 13.2. The dye solution without lysine may be
adequate. To achieve higher recoveries from beryllium oxide (especially
used for all analytical purposes and also provides superior
“high-fired” BeO), a heat block, oven or heating bath is required.
detection limits (9).
7.3 Laboratory Supplies:
NOTE2—Foron-siteanalysis,itisrecommendedthattheextractionand
7.3.1 Centrifuge tubes, plastic, 15-mL (plus 50-mL, if
detection solutions be prepared in a fixed-site laboratory or other such
necessary).
controlled environment prior to transport to the field.
7.3.2 Syringe filters,0.2to0.45-µmnylon,polyethersulfone
8. Procedure
or hydrophilic polypropylene, 13- or 25-mm diameter, in
plastic housings. 8.1 Sampling:
8.1.1 Air Samples—Collect workplace air samples for be-
7.3.3 Syringes, plastic, 5-mL or 10-mL.
ryllium in accordance with Test Method D7035 and Guide
7.3.4 Pipetters, mechanical, of assorted sizes as needed,
D8358, using personal sampling pumps calibrated in accor-
meeting requirements of Specification E1154.
dance with Practice D5337.
7.3.5 Pipet tips, plastic, disposable, of assorted sizes as
8.1.2 Wipe Samples—Collect surface wipe samples for be-
needed.
ryllium in accordance with Practices D6966 and D7296 using
7.3.6 Fluorescence cuvettes, disposable, low fluorescence,
wipe materials that comply with Specification D7707.
10-mm path length, transparent to UV/Vis radiation.
7.3.7 Labware, plastic (for example, beakers, flasks, gradu-
NOTE 3—Practice D7296 should only be used when wetted wipe
samplingisnotphysicallyfeasible(forexample,ifthesurfacetobewiped
ated cylinders, etc.), of assorted sizes as needed.
would be compromised by use of wetted wipes). Otherwise, Practice
7.3.8 Forceps, plastic or plastic-coated.
D6966 should be used.
7.3.9 Personal protective wear, for example, respirators,
8.1.3 Vacuum Samples—If wipe sampling is inadvisable for
masks, gloves, lab coats, safety eyewear, etc., as needed.
surface dust sampling, collect surface vacuum samples for
7.3.10 Thermometer, to at least 100°C.
beryllium in accordance with Practice D7144.
7.3.11 Other general laboratory apparatus, as needed.
8.1.4 Sample Transport—If applicable (that is, if samples
7.4 Reagents—Useonlyreagentsofanalyticalspectroscopic are transported to a different location prior to sample prepara-
grade or greater purity.
tion and analysis), follow sampling chain-of-custody proce-
dures to document sample traceability. Ensure that the docu-
7.4.1 Water—Unless otherwise indicated, references to wa-
tershallbeunderstoodtomeanreagentasdefinedbyTypeIof mentation that accompanies the samples is suitable for a chain
of custody to be established in accordance with Guide D4840.
Specification D1193 (ASTM Type I Water: minimum resis-
tance of 18 MΩ-cm or equivalent)
8.2 Sample Preparation—Wearappropriatepersonalprotec-
7.4.2 Calibration Stock Solution—1000 ppm beryllium in
tion during sample preparation and analysis activities. Perform
dilute nitric acid or equivalent.
sample preparation and analysis in a clean area that is well
7.4.3 Ethylenediaminetetraacetic acid (EDTA) disodium
removed from any possible beryllium contamination.
salt dihydrate.
8.2.1 Extraction of Air Filter or Vacuum Samples:
7.4.4 L-lysine monohydrochloride.
8.2.1.1 Don clean gloves and open the samplers. Use either
7.4.5 10-hydroxybenzo[h]quinoline-7-sulfonate (10- technique (1)or(2) to perform sample extraction on each
HBQS). collected sample:
(1)Using forceps, remove the filter from the cassette and
7.4.6 Sodium hydroxide.
place it into 15-mLcentrifuge tube.The interior of the cassette
7.4.7 Extraction (or Dissolution) Solution—1%ammonium
shall be rinsed with extraction solution or wiped with another
bifluoride (NH HF ) solution (aqueous) for dissolution of
4 2
clean filter, and included in the centrifuge tube. For each
beryllium in collected particulate matter. (Warning—
vacuum sample, quantitatively transfer all loose dust into the
Ammonium bifluoride will etch glass, so it is essential that all
centrifuge tube before removing the filter and then rinsing or
NH HF solutions be contained in plastic labware.)
4 2
wiping the inside walls of the sampler.
7.4.8 Detection Solution—63.4 µM 10-
(2)Alternatively,theextractionshallbecarriedoutdirectly
hydroxybenzo[h]quinoline-7-sulfonate (10-HBQS) / 2.5 mM
within the sampling cassette (see Test Method D7035 and
ethylenediaminetetraacetic acid (EDTA)/50.8 mM lysine
Guide D8358).
monohydrochloride (pH adjusted to 12.8 with NaOH): The
8.2.1.2 Pipet 5 mL of 1% ammonium bifluoride extraction
aqueous detection reagent is prepared by the addition of 12.5
solution (see 7.4.7) into the centrifuge tubes or cassettes
mL of 10.7 mM ethylenediaminetetraacetic acid (EDTA)
containing the air filter or vacuum samples.
disodium salt dihydrate and 25 mL of 107 mM L-lysine
8.2.1.3 Cap the centrifuge tubes or cassettes, and agitate or
monohydrochloride to 3 mL of 1.1 mM 10-
heat the samples:
hydroxybenzo[h]quinoline-7-sulfonate (10-HBQS). The pH is
(1)Activate the shaker, rotator, or ultrasonic bath, and
adjustedto12.85withadditionofsodiumhydroxideandwater
agitate for a minimum of 30 minutes; or
added to a total of 50 mL (1-3). An alternative preparation of
(2)Preheat the heat block, oven or heating bath to 85°C
dye solution without lysine may be made by adding 1.104 g of
(65°C), and heat the samples for a minimum of 30 minutes.
EDTAand64µmolesofthe10-HBQSdyein900mLofwater.
After a clear solution is obtained, 114.5 mLof 2.5 N NaOH is
NOTE 4—Extraction is an example of a dissolution and solvating
addedandmixedtoobtainthefinaldyesolution.ThepHofthe process.Methodevaluationmightindicatethatforcompletedissolutionof
D7202 − 22
beryllium,itmaybenecessaryforthedissolutionprocesstobeassistedby
is a 20× dilution. Either of the two dye solutions (with or
ultrasonic energy, heat or longer treatment periods to obtain acceptable
without lysine) may be used.
recoveries. This will be dependent upon the sample media, particle
8.2.4.2 For samples where ultra-trace beryllium measure-
physical characteristics (such as shape and size) and the inertness of
ments are required, pipet 400 µL of filtered solution extracts
beryllium-containing compounds. Heating to between 80 and 90°C is
into fluorescence cuvettes. To this add 1.6 mL of detection
required for the dissolution of refractory compounds such as “high-fired”
beryllium oxide.
(dye) solution and ensure these are mixed well. This is a 5×
dilution (10).Thelysine-freedyesolutionmayalsobeusedfor
8.2.1.4 If the samples are heated during the extraction step,
obtaining even lower detection limits at a dilution ratio of 3×,
theyshallbecooledtoambienttemperaturebeforealiquotsare
where 1.33 mL of the dye solution is mixed with 0.67 mL of
removed prior to addition of the detection solution.
the filtered solution extracts (Table 1).
8.2.2 Extraction of Wipe Samples:
8.2.2.1 Doncleanglovesand,usingforceps,placethewipes NOTE 10—If excess iron is present (typically more than 20 µM) in the
sample, the resulting measurement solution may be golden-yellow. In this
into 15- or 50-mL centrifuge tubes.
case the solution should be left for an hour for iron to precipitate and the
NOTE5—Thesizeofthewipesusedforsampling(8.1.2)willdetermine
solution to clarify to colorless/near colorless. The solution should be
thesizeofthecentrifugetubestouseforextraction.Smallerwipescanbe re-filtered using the same procedure as was conducted for filtering the
placed into 15-mL centrifuge tubes. Larger wipes, however, will require dissolution solution and then used for the fluorescence measurement. The
the use of larger tubes such as 50-mL volume. Use of 15-mL centrifuge waitingtimeisreducedwhen0.2-micrometreporesizefiltersmadeoutof
tubes will facilitate achievement of the lower detection limit. polyethersulfone or hydrophilic polypropylene are used.
NOTE 11—A 20× dilution is typically used for samples between about
8.2.2.2 Pipet 5 mL or 10 mL of 1% ammonium bifluoride
0.2 and 4 µg of beryllium (the method detection limit for beryllium is
extraction solution (see 7.4.7) into the centrifuge tubes con-
about 0.005 µg or lower depending on the fluorescence instrument).
Preparationforultra-traceanalysisusesa5×dilutionforsamplesbetween
taining the wipe samples.
about 0.02 and 0.4 µg of beryllium (the method detection limit for
NOTE 6—The size of the wipes used for sampling (8.1.2) and the size
beryllium is about 0.0008 µg or lower depending on the fluorescence
of the centrifuge tubes used for extraction will determine the volume of
instrument) (10). When 3× dilution ratio is used with lysine-free dye
extractionsolutiontoadd.Smallerwipesin15-mLtubeswillrequireonly
solution, one can determine beryllium down to 0.002 µg (as the method
5 mL of extraction solution, but larger wipes in 50-mL tubes will require
detection limit is about 0.0001 µg).
a minimum of 10 mL of extraction solution to ensure complete wetting
8.3 Fluorometer Set-Up—Set up the fluorometer for excita-
and effective extraction. Use of a 15-mL centrifuge tube and 5 mL of
tion radiation from 360 to 390 nm and measurement of
extraction solution will result in a lower detection limit than with use of
the larger centrifuge tube and a larger extraction solution volume. emission in a spectral window selected from a range of (at
least)440to490nm.Allowappropriatewarm-upofthesystem
8.2.2.3 Cap the centrifuge tubes, and agitate or heat the
prior to analysis (follow manufacturer’s instructions).
samples:
(1)Activate the mechanical shaker, agitator, or ultrasonic
NOTE 12—For fluorescence measurement, an emission band pass filter
with peak transmission wavelength at ~475 nm and with a full width at
bath, and agitate the samples for a minimum of 30 minutes; or
half maximum (FWHM) of less than 610 nm have been shown to be
(2)Preheat the heat block, oven, or heating bath to 85°C
effective (1).
(65°C), and heat the samples for a minimum of 60 minutes.
8.4 Preparation of Calibration Standards—Using calibra-
NOTE 7—Extraction is an example of a dissolution and solvating
tion stock solution and 1% aqueous ammonium bifluoride
process.Methodevaluationmightindicatethatforcompletedissolutionof
solution, prepare at least four standards covering the concen-
beryllium,itmaybenecessaryforthedissolutionprocesstobeassistedby
tration range of interest.
ultrasonic energy, heat or longer treatment periods to obtain acceptable
recoveries. This will be dependent upon the sample media, particle
NOTE 13—For example: To measure from about 0.02 to 4 µg of
physical characteristics (such as shape and size) and the inertness of
beryllium in samples, calibration standards from 0 to 800 parts per billion
beryllium-containing compounds. Heating to between 80 and 90°C is
(ppb) are recommended (see Table 1).
required for the dissolution of refractory compounds such as “high-fired”
beryllium oxide.
8.5 Calibration and Specifications:
8.5.1 Calibration Blank and Calibration Stock Standard
8.2.2.4 If the samples are heated during the extraction step,
Solutions Preparation—The calibration blank is prepared by
theyshallbecooledtoambienttemperaturebeforealiquotsare
adding in a proportion of 1:19 (by volume) the 0 ppb standard
removed prior to addition of the detection solution.
and the detection solution in a cuvette suitable for fluorescent
8.2.3 Filtration—Filter aliquots (for example, 5 mL) of
measurements. Ensure that these are mixed properly. Calibra-
extract solution through inert microfilters.
tionstandardsolutionsaremadeinasimilarfashion,wherethe
NOTE8—Filterswith0.2to0.45-micrometreporesizehavebeenfound
calibration standard and the detector solution are mixed in a
to be acceptable. Preferred filters are made out of nylon, polyethersulfone
volumetricratioof1:19(a20×dilution).Atleastfourstandard
or hydrophilic polypropylene.
measurement solutions, plus a blank, shall be made for
NOTE9—Thefiltrationprocesscanbecarriedoutbyattachinga25-mm
calibration.
diameter syringe filter to a 5- or 10-mLLuer lock syringe and pouring the
liquid contents into the syringe. The liquid is forced out through the filter
NOTE 14—For routine beryllium analyses, calibration stock standard
into a separate 15-mL centrifuge tube.
solution concentrations of 0, 10, 40, 200 and 800 ppb beryllium in 1 %
ammonium bifluoride are preferred; see Table 1. For ultra-trace beryllium
8.2.4 Measurement Solution Preparation:
determinations, calibration stock standard solution concentrations of 0, 1,
8.2.4.1 Forroutinesamples,pipet100µLoffilteredsolution
4,20and80ppbberylliumin1%ammoniumbifluoridearepreferred;see
extracts into fluorescence cuvettes. To this add 1.9 mL of
Table 1. The calibration stock solution standards for ultra-trace determi-
detection (dye) solution and ensure these are mixed well. This nations may be prepared by a 10× dilution of the routine calibration stock
D7202 − 22
TABLE 1 Preparation of Calibration Standards (Example)
Final Concentration of
Concentration of Beryllium Used in Calibration
A
Beryllium (ppb) in Calibra
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7202 − 21 D7202 − 22
Standard Test Method for
Determination of Beryllium in the Workplace by Extraction
and Optical Fluorescence Detection
This standard is issued under the fixed designation D7202; 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 beryllium by sampling workplace air and surface dust.
1.2 This test method assumes that air and surface samples are collected using appropriate and applicable ASTM International
standard practices for sampling of workplace air and surface dust. These samples are typically collected using air filter sampling,
vacuum sampling or wiping techniques. See Guide E1370 for guidance on air sampling strategies, and Guide D7659 for guidance
on selection of surface sampling techniques.
1.3 Determination of beryllium in soil is not within the scope of this test method. See Test Method D7458 for determination of
beryllium in soil samples.
1.4 This test method includes a procedure for extraction (dissolution) of beryllium in weakly acidic medium (pH of 1 % aqueous
ammonium bifluoride is 4.8), followed by field analysis of aliquots of the extract solution using a beryllium-specific-optically
fluorescent dye.
1.5 The procedure is suitable for on-site use in the field for occupational and environmental hygiene monitoring purposes. The
method is also applicable for use in fixed-site laboratories.
1.6 No detailed operating instructions are provided because of differences among various makes and models of suitable
fluorometric instruments. Instead, the analyst shall follow the instructions provided by the manufacturer of the particular
instrument. This test method does not address comparative accuracy of different devices or the precision between instruments of
the same make and model.
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 This test method contains notes that are explanatory and not part of mandatory requirements of the standard.
1.9 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.
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 Sept. 1, 2021Sept. 1, 2022. Published April 2022September 2022. Originally approved in 2005. Last previous edition approved in 20152021 as
D7202 – 15.D7202 – 21. DOI: 10.1520/D7202-21.10.1520/D7202-22.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7202 − 22
1.10 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:
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
D6966 Practice for Collection of Settled Dust Samples Using Wipe Sampling Methods for Subsequent Determination of Metals
D7035 Test Method for Determination of Metals and Metalloids in Airborne Particulate Matter by Inductively Coupled Plasma
Atomic Emission Spectrometry (ICP-AES)
D7144 Practice for Collection of Surface Dust by Micro-vacuum Sampling for Subsequent Determination of Metals and
Metalloids
D7296 Practice for Collection of Settled Dust Samples Using Dry Wipe Sampling Methods for Subsequent Determination of
Beryllium and Compounds
D7458 Test Method for Determination of Beryllium in Soil and Sediment Using Ammonium Bifluoride Extraction and
Fluorescence Detection
D7659 Guide for Strategies for Surface Sampling of Metals and Metalloids for Worker Protection
D7707 Specification for Wipe Sampling Materials for Beryllium in Surface Dust
D8358 Guide for Assessment and Inclusion of Wall Deposits in the Analysis of Single-Stage Samplers for Airborne Particulate
Matter
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E882 Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
E1154 Specification for Piston or Plunger Operated Volumetric Apparatus
E1370 Guide for Air Sampling Strategies for Worker and Workplace Protection
3. Terminology
3.1 Definitions—For definitions of terms not appearing here, see Terminology D1356.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 wipe sample, n—sample collected by wiping a representative surface of known area, as determined by Practice D6966, or
equivalent method, with an acceptable wipe material as defined in Specification D7707.
4. Summary of Test Method
4.1 Particles potentially containing beryllium from workplace air or surfaces, or both, are collected in the field using procedures
described in ASTM International standards. To extract (or dissolve) beryllium in the collected samples, the media in or on which
the samples are collected (that is, air sample, vacuum sample or wipe) are treated using an acidic extraction solution containing
dilute ammonium bifluoride, NH HF (1). The presence of active fluoride ions (HF by dissociation of ammonium bifluoride in
4 2
acidic medium) enables dissolution of refractory materials such as “high-fired” beryllium oxide. The extraction solution produced
from each sample is then filtered and an aliquot of this extract is added to a pH-adjusted detection solution which contains a
beryllium-specific optical fluorescence reagent (1, 2). The fluorescence exhibited by this final solution is then measured on a
calibrated fluorometer to quantify the amount of beryllium in the sample (3).
5. Significance and Use
5.1 Exposure to beryllium can cause a potentially fatal disease, and occupational exposure limits for beryllium in air and on
surfaces have been established to reduce exposure risks to potentially affected workers (4-7). Sampling and analytical methods for
beryllium are needed in order to meet the challenges relating to exposure assessment and risk reduction. Sampling and analysis
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The boldface numbers in parentheses refer to a list of references at the end of this standard.
D7202 − 22
methods, such as the procedure described in this test method, are desired in order to facilitate on-site and fixed-site laboratory
measurement of trace beryllium. Beryllium analysis results can then be used as a basis for exposure assessment and protection of
human health.
6. Interferences
6.1 This test method is highly specific for beryllium. Other solvated metal ions are either bound by ethylenediaminetetraacetic acid
(EDTA) in the detection solution, or they precipitate out due to the high alkalinity of the detection solution (1). In case the sample
is suspected of having fluorescent organic contaminants that are suspected to be present, then their presence can be checked and
removed (8).
6.2 If the samples are suspected of having a contaminant that fluoresces and has excitation and emission spectra that overlap with
that of the signal produced by the fluorescent dye bound to beryllium, then this contaminant needs to be removed. The presence
of such a contaminant can be verified by subjecting the filtered sample to fluorescence excitation after the extraction step (without
adding the fluorescent dye). If a fluorescence signal is detected, then that signal is ascribed to the presence of a fluorescent
contaminant. To remove the contaminant, high-purity activated charcoal is added to the beryllium extraction solution and the
extraction procedure is carried out at elevated temperature (80 to 90 °C for at least 45 minutes). If the beryllium extraction
procedure has already been performed, then after the addition of activated charcoal, the extraction process is repeated at the
elevated temperature. The solution is filtered to remove the activated charcoal before making the measurement solution. The
measurement solution is made by the addition of the fluorescent dye solution to an aliquot of the extraction solution. Details of
this process have been published (8).
6.3 If iron is present in high excess in the sample (typically more than 20 μM), the resulting measurement solution may appear
golden-yellow. In this case the solution should be left for an hour or more for the iron to precipitate. The solution should then be
re-filtered using the same procedure as for filtering the dissolution solution (after the dissolution step), prior to fluorescence
measurement.
7. Apparatus
7.1 Sampling Equipment:
7.1.1 Air Sampling—Use air samplers and filters for collecting personal air samples as described in Test Method D7035 and Guide
D8358.
7.1.2 Wipe Sampling—Use wipe sampling apparatus for collecting surface dust samples as described in Practice D6966 (or
Practice D7296 in special cases), using wipes meeting the specifications described in Specification D7707.
7.1.3 Vacuum Sampling—If wipe sampling is not advisable for surface sample collection, use vacuum sampling apparatus for
collecting surface dust samples as described in Practice D7144.
7.2 Instrumentation:
7.2.1 Ultraviolet/Visible (UV/Vis) Fluorometer, with irradiance excitation lamp (excitation λ = 380 nm) and time-integrating
visible detector (400–700 nm, λmax ≈ 475 nm).
7.2.2 Mechanical Agitator or Heating Source, shaker, rotator or ultrasonic bath; or heat block, oven or heating bath.
NOTE 1—For routine samples, a shaker, rotator, or ultrasonic bath is adequate. To achieve higher recoveries from beryllium oxide (especially “high-fired”
BeO), a heat block, oven or heating bath is required.
7.3 Laboratory Supplies:
7.3.1 Centrifuge tubes, plastic, 15-mL (plus 50-mL, if necessary).
7.3.2 Syringe filters, 0.2 to 0.45-μm nylon, polyethersulfone or hydrophilic polypropylene, 13- or 25-mm diameter, in plastic
housings.
D7202 − 22
7.3.3 Syringes, plastic, 5-mL or 10-mL.
7.3.4 Pipetters, mechanical, of assorted sizes as needed, meeting requirements of Specification E1154.
7.3.5 Pipet tips, plastic, disposable, of assorted sizes as needed.
7.3.6 Fluorescence cuvettes, disposable, low fluorescence, 10-mm path length, transparent to UV/Vis radiation.
7.3.7 Labware, plastic (for example, beakers, flasks, graduated cylinders, etc.), of assorted sizes as needed.
7.3.8 Forceps, plastic or plastic-coated.
7.3.9 Personal protective wear, for example, respirators, masks, gloves, lab coats, safety eyewear, etc., as needed.
7.3.10 Thermometer, to at least 100 °C.
7.3.11 Other general laboratory apparatus, as needed.
7.4 Reagents—Use only reagents of analytical spectroscopic grade or greater purity.
7.4.1 Water—Unless otherwise indicated, references to water shall be understood to mean reagent as defined by Type I of
Specification D1193 (ASTM Type I Water: minimum resistance of 18 MΩ-cm or equivalent)
7.4.2 Calibration Stock Solution—1000 ppm beryllium in dilute nitric acid or equivalent.
7.4.3 Ethylenediaminetetraacetic acid (EDTA) disodium salt dihydrate.
7.4.4 L-lysine monohydrochloride.
7.4.5 10-hydroxybenzo[h]quinoline-7-sulfonate (10-HBQS).
7.4.6 Sodium hydroxide.
7.4.7 Extraction (or Dissolution) Solution—1 % ammonium bifluoride (NH HF ) solution (aqueous) for dissolution of beryllium
4 2
in collected particulate matter. (Warning—Ammonium bifluoride will etch glass, so it is essential that all NH HF solutions be
4 2
contained in plastic labware.)
7.4.8 Detection Solution—63.4 μM 10-hydroxybenzo[h]quinoline-7-sulfonate (10-HBQS) / 2.5 mM ethylenediaminetetraacetic
acid (EDTA)/50.8 mM lysine monohydrochloride (pH adjusted to 12.8 with NaOH): The aqueous detection reagent is prepared
by the addition of 12.5 mL of 10.7 mM ethylenediaminetetraacetic acid (EDTA) disodium salt dihydrate and 25 mL of 107 mM
L-lysine monohydrochloride to 3 mL of 1.1 mM 10-hydroxybenzo[h]quinoline-7-sulfonate (10-HBQS). The pH is adjusted to
12.85 with addition of sodium hydroxide and water added to a total of 50 mL (1-3). An alternative preparation of dye solution
without lysine may be made by adding 1.104 g of EDTA and 64 μmoles of the 10-HBQS dye in 900 mL of water. After a clear
solution is obtained, 114.5 mL of 2.5 N NaOH is added and mixed to obtain the final dye solution. The pH of the dye solution
is 13.2. The dye solution without lysine may be used for all analytical purposes and also provides superior detection limits.limits
(9).
NOTE 2—For on-site analysis, it is recommended that the extraction and detection solutions be prepared in a fixed-site laboratory or other such controlled
environment prior to transport to the field.
8. Procedure
8.1 Sampling:
8.1.1 Air Samples—Collect workplace air samples for beryllium in accordance with Test Method D7035 and Guide D8358, using
personal sampling pumps calibrated in accordance with Practice D5337.
D7202 − 22
8.1.2 Wipe Samples—Collect surface wipe samples for beryllium in accordance with Practices D6966 and D7296 using wipe
materials that comply with Specification D7707.
NOTE 3—Practice D7296 should only be used when wetted wipe sampling is not physically feasible (for example, if the surface to be wiped would be
compromised by use of wetted wipes). Otherwise, Practice D6966 should be used.
8.1.3 Vacuum Samples—If wipe sampling is inadvisable for surface dust sampling, collect surface vacuum samples for beryllium
in accordance with Practice D7144.
8.1.4 Sample Transport—If applicable (that is, if samples are transported to a different location prior to sample preparation and
analysis), 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.
8.2 Sample Preparation—Wear appropriate personal protection during sample preparation and analysis activities. Perform sample
preparation and analysis in a clean area that is well removed from any possible beryllium contamination.
8.2.1 Extraction of Air Filter or Vacuum Samples:
8.2.1.1 Don clean gloves and open the samplers. Use either technique (1) or (2) to perform sample extraction on each collected
sample:
(1) Using forceps, remove the filter from the cassette and place it into 15-mL centrifuge tube. The interior of the cassette shall
be rinsed with extraction solution or wiped with another clean filter, and included in the centrifuge tube. For each vacuum sample,
quantitatively transfer all loose dust into the centrifuge tube before removing the filter and then rinsing or wiping the inside walls
of the sampler.
(2) Alternatively, the extraction shall be carried out directly within the sampling cassette (see Test Method D7035 and Guide
D8358).
8.2.1.2 Pipet 5 mL of 1 % ammonium bifluoride extraction solution (see 7.4.7) into the centrifuge tubes or cassettes containing
the air filter or vacuum samples.
8.2.1.3 Cap the centrifuge tubes or cassettes, and agitate or heat the samples:
(1) Activate the shaker, rotator, or ultrasonic bath, and agitate for a minimum of 30 minutes; or
(2) Preheat the heat block, oven or heating bath to 85 °C (65 °C), and heat the samples for a minimum of 30 minutes.
NOTE 4—Extraction is an example of a dissolution and solvating process. Method evaluation might indicate that for complete dissolution of beryllium,
it may be necessary for the dissolution process to be assisted by ultrasonic energy, heat or longer treatment periods to obtain acceptable recoveries. This
will be dependent upon the sample media, particle physical characteristics (such as shape and size) and the inertness of beryllium-containing compounds.
Heating to between 80 and 90 °C is required for the dissolution of refractory compounds such as “high-fired” beryllium oxide.
8.2.1.4 If the samples are heated during the extraction step, they shall be cooled to ambient temperature before aliquots are
removed prior to addition of the detection solution.
8.2.2 Extraction of Wipe Samples:
8.2.2.1 Don clean gloves and, using forceps, place the wipes into 15- or 50-mL centrifuge tubes.
NOTE 5—The size of the wipes used for sampling (8.1.2) will determine the size of the centrifuge tubes to use for extraction. Smaller wipes can be placed
into 15-mL centrifuge tubes. Larger wipes, however, will require the use of larger tubes such as 50-mL volume. Use of 15-mL centrifuge tubes will
facilitate achievement of the lower detection limit.
8.2.2.2 Pipet 5 mL or 10 mL of 1 % ammonium bifluoride extraction solution (see 7.4.7) into the centrifuge tubes containing the
wipe samples.
NOTE 6—The size of the wipes used for sampling (8.1.2) and the size of the centrifuge tubes used for extraction will determine the volume of extraction
solution to add. Smaller wipes in 15-mL tubes will require only 5 mL of extraction solution, but larger wipes in 50-mL tubes will require a minimum
of 10 mL of extraction solution to ensure complete wetting and effective extraction. Use of a 15-mL centrifuge tube and 5 mL of extraction solution will
result in a lower detection limit than with use of the larger centrifuge tube and a larger extraction solution volume.
D7202 − 22
8.2.2.3 Cap the centrifuge tubes, and agitate or heat the samples:
(1) Activate the mechanical shaker, agitator, or ultrasonic bath, and agitate the samples for a minimum of 30 minutes; or
(2) Preheat the heat block, oven, or heating bath to 85 °C (65 °C), and heat the samples for a minimum of 60 minutes.
NOTE 7—Extraction is an example of a dissolution and solvating process. Method evaluation might indicate that for complete dissolution of beryllium,
it may be necessary for the dissolution process to be assisted by ultrasonic energy, heat or longer treatment periods to obtain acceptable recoveries. This
will be dependent upon the sample media, particle physical characteristics (such as shape and size) and the inertness of beryllium-containing compounds.
Heating to between 80 and 90 °C is required for the dissolution of refractory compounds such as “high-fired” beryllium oxide.
8.2.2.4 If the samples are heated during the extraction step, they shall be cooled to ambient temperature before aliquots are
removed prior to addition of the detection solution.
8.2.3 Filtration—Filter aliquots (for example, 5 mL) of extract solution through inert microfilters.
NOTE 8—Filters with 0.2 to 0.45-micrometre pore size have been found to be acceptable. Preferred filters are made out of nylon, polyethersulfone or
hydrophilic polypropylene.
NOTE 9—The filtration process can be carried out by attaching a 25-mm diameter syringe filter to a 5- or 10-mL Luer lock syringe and pouring the liquid
contents into the syringe. The liquid is forced out through the filter into a separate 15-mL centrifuge tube.
8.2.4 Measurement Solution Preparation:
8.2.4.1 For routine samples, pipet 100 μL of filtered solution extracts into fluorescence cuvettes. To this add 1.9 mL of detection
(dye) solution and ensure these are mixed well. This is a 20× dilution. Either of the two dye solutions (with or without lysine) may
be used.
8.2.4.2 For samples where ultra-trace beryllium measurements are required, pipet 400 μL of filtered solution extracts into
fluorescence cuvettes. To this add 1.6 mL of detection (dye) solution and ensure these are mixed well. This is a 5× dilution (910).
The lysine-free dye solution may also be used for obtaining even lower detection limits at a dilution ratio of 3×, where 1.33 mL
of the dye solution is mixed with 0.67 mL of the filtered solution extracts (Table 1).
NOTE 10—If excess iron is present (typically more than 20 μM) in the sample, the resulting measurement solution may be golden-yellow. In this case
the solution should be left for an hour for iron to precipitate and the solution to clarify to colorless/near colorless. The solution should be re-filtered using
the same procedure as was conducted for filtering the dissolution solution and then used for the fluorescence measurement. The waiting time is reduced
when 0.2-micrometre pore size filters made out of polyethersulfone or hydrophilic polypropylene are used.
NOTE 11—A 20× dilution is typically used for samples between about 0.2 and 4 μg of beryllium (the method detection limit for beryllium is about 0.005
μg or lower depending on the fluorescence instrument). Preparation for ultra-trace analysis uses a 5× dilution for samples between about 0.02 and 0.4
μg of beryllium (the method detection limit for beryllium is about 0.0008 μg or lower depending on the fluorescence instrument) (910). When 3× dilution
ratio is used with lysine-free dye solution, one can determine beryllium down to 0.002 μg (as the method detection limit is about 0.0001 μg).
8.3 Fluorometer Set-Up—Set up the fluorometer for excitation radiation from 360 to 390 nm and measurement of emission in a
spectral window selected from a range of (at least) 440 to 490 nm. Allow appropriate warm-up of the system prior to analysis
(follow manufacturer’s instructions).
NOTE 12—For fluorescence measurement, an emission band pass filter with peak transmission wavelength at ~475 nm and with a full width at half
maximum (FWHM) of less than 610 nm have been shown to be effective (1).
8.4 Preparation of Calibration Standards—Using calibration stock solution and 1 % aqueous ammonium bifluoride solution,
prepare at least four standards covering the concentration range of interest.
NOTE 13—For example: To measure from about 0.02 to 4 μg of beryllium in samples, calibration standards from 0 to 800 parts per billion (ppb) are
recommended (see Table 1).
8.5 Calibration and Specifications:
8.5.1 Calibration Blank and Calibration Stock Standard Solutions Preparation—The calibration blank is prepared by adding in
D7202 − 22
TABLE 1 Preparation of Calibration Standards (Example)
Final Concentration of
Concentration of Beryllium Used in Calibration
A
Beryllium (ppb) in Calibration Corresponding Amount of Beryllium (Be) in Media (Filter or Wipe) (μg)
Standards
Standard Solutions
0.1 mL of 0 ppb standard 0.0 Corresponds to 0 μg beryllium per sample when DF = 20
+ 1.9 mL of detection solution (DF = 20)
0.1 mL of 10 ppb standard 0.50 Corresponds to 0.050 μg beryllium per sample when DF = 20
+ 1.9 mL of detection solution (DF = 20)
0.1 mL of 40 ppb standard 2.0 Corresponds to 0.20 μg beryllium per sample when DF = 20
+ 1.9 mL of detection solution (DF = 20)
0.1 mL of 200 ppb standard 10.0 Corresponds to 1.0 μg beryllium per sample when DF = 20
+ 1.9 mL of detection solution (DF = 20)
0.1 mL of 800 ppb standard 40.0 Corresponds to 4.0 μg beryllium per sample when DF = 20
+ 1.9 mL of detection solution (DF = 20)
0.4 mL of 0 ppb standard 0.0 Corresponds to 0 μg beryllium per sample when DF = 5
...