ASTM D7574-23

Standard Test Method for Determination of Bisphenol A in Environmental Waters by Liquid Chromatography/Tandem Mass Spectrometry

SIGNIFICANCE AND USE
5.1 The first reported synthesis of BPA was by the reaction of phenol with acetone by Zincke.4 BPA has become an important high volume industrial chemical used in the manufacture of polycarbonate plastic and epoxy resins. Polycarbonate plastic and resins are used in numerous products including electrical and electronic equipment, automobiles, sports and safety equipment, reusable food and drink containers, electrical laminates for printed circuit boards, composites, paints, adhesives, dental sealants, protective coatings and many other products.5  
5.2 The environmental source of BPA is predominantly from the decomposition of polycarbonate plastics and resins. BPA is not classified as bio-accumulative by the U.S. Environmental Protection Agency and will biodegrade. BPA has been reported to have adverse effects in aquatic organisms and may be released into environmental waters directly at trace levels through landfill leachate and POTW effluents. This method has been investigated for use with surface water and secondary and tertiary POTW effluent samples therefore, it is applicable to these matrices only. It has not been investigated for use with salt water or solid sample matrices.
SCOPE
1.1 This test method covers the determination of bisphenol A (BPA) extracted from water utilizing solid phase extraction (SPE), separated using liquid chromatography (LC) and detected with tandem mass spectrometry (MS/MS). BPA is qualitatively and quantitatively determined by this method. This test method adheres to multiple reaction monitoring (MRM) mass spectrometry.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 The method detection limit (MDL) and reporting limit (RL) for BPA are listed in Table 1.  
1.4 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.  
1.5 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: 14-Apr-2023
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: D19 - Water
• Drafting Committee: D19.06 - Methods for Analysis for Organic Substances in Water

Relations

• Refers: ASTM D3694-96(2024) - Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents
• Effective Date: 01-Apr-2024
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM D5905-98(2013) - Standard Practice for the Preparation of Substitute Wastewater
• Effective Date: 01-Jan-2013
• Refers: ASTM D2777-12 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Jun-2012
• Refers: ASTM D3856-11 - Standard Guide for Management Systems in Laboratories Engaged in Analysis of Water
• Effective Date: 15-Nov-2011
• Refers: ASTM D3694-96(2011) - Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents
• Effective Date: 01-May-2011
• Refers: ASTM D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• Refers: ASTM D5905-98(2008) - Standard Practice for the Preparation of Substitute Wastewater
• Effective Date: 15-Jul-2008
• Refers: ASTM D2777-08 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Jan-2008
• Refers: ASTM D1129-06ae1 - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D1129-06a - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D2777-06 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Aug-2006
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1129-06 - Standard Terminology Relating to Water
• Effective Date: 15-Feb-2006
• Refers: ASTM D3856-95(2006) - Standard Guide for Good Laboratory Practices in Laboratories Engaged in Sampling and Analysis of Water
• Effective Date: 15-Feb-2006

Overview

ASTM D7574-23 is a standard test method developed by ASTM International for the detection and quantification of bisphenol A (BPA) in environmental waters using liquid chromatography/tandem mass spectrometry (LC/MS/MS). BPA is a widely produced industrial chemical used in the manufacture of polycarbonate plastics and epoxy resins, which are commonly found in consumer goods, electronics, automobile parts, food and drink containers, printed circuit boards, composites, coatings, adhesives, and more.

The standard is vital for ensuring accurate measurement of trace BPA levels in water samples, primarily surface water and treated effluents, supporting environmental monitoring and regulatory compliance.

Key Topics

• Significance of BPA Monitoring
  BPA enters the environment mainly through the degradation of polycarbonate plastics and resins. While it is not classified as bioaccumulative by the US Environmental Protection Agency, BPA is known to biodegrade and can be harmful to aquatic organisms at low concentrations.

• Applicability and Scope

  • This method is validated for surface waters, and secondary or tertiary publicly owned treatment works (POTW) effluent.
  • The standard has not been evaluated for marine waters or solid matrices.
  • Detection and reporting limits are set to ensure accurate trace analysis: the method detection limit (MDL) is 5 ng/L, with a reporting range of 20–600 ng/L.

• Test Method Summary

  1. Sample Preparation: Water samples are collected in pre-cleaned, BPA-free, amber glass bottles, acidified to pH 2, and stored at 0–6 °C.
  2. Solid Phase Extraction (SPE): BPA is extracted from water by adjusting the sample pH, passing it through an SPE cartridge, concentrating the eluate, and solvent exchange into methanol.
  3. Analysis by LC/MS/MS: Using LC paired with tandem mass spectrometry in multiple reaction monitoring (MRM) mode, BPA is separated and detected with high sensitivity and specificity.
  4. Calibration and Quality Control: The method requires calibration with standard solutions, use of internal and surrogate standards, and rigorous quality controls (including method blanks, laboratory control samples, and spike recoveries).

• Precision and Accuracy
  The standard includes criteria for calibration acceptance, method performance (recovery and precision), and procedures for initial demonstration of capability and ongoing quality checks to ensure data integrity.

Applications

• Environmental Monitoring:

  • Analysis of surface water and treated wastewater for regulatory and research purposes.
  • Tracking BPA contamination from consumer products, industrial discharges, or landfill leachates.

• Regulatory Compliance:

  • Supports assessment for compliance with environmental protection guidelines and standards for water quality.
  • Enables authorities and organizations to detect and report BPA concentrations at trace levels.

• Risk Assessment and Research:

  • Provides reliable data for evaluating the potential ecological and health impacts of BPA in aquatic environments.
  • Useful for studies on the fate and transport of BPA and related compounds in various water bodies.

• Quality Assurance in Laboratories:

  • Establishes procedures for consistent instrument calibration, quality control, and data validation in environmental testing laboratories.

Related Standards

• ASTM D1129: Terminology Relating to Water
• ASTM D1193: Specification for Reagent Water
• ASTM D2777: Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• ASTM D3694: Practices for Preparation of Sample Containers and for Preservation of Organic Constituents
• ASTM D3856: Guide for Management Systems in Laboratories Engaged in Analysis of Water
• ASTM D5847: Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
• ASTM D5905: Practice for the Preparation of Substitute Wastewater

By following ASTM D7574-23, laboratories and environmental professionals are equipped with a robust, internationally recognized test method for precise quantification of bisphenol A in environmental water samples-contributing to improved water quality monitoring and environmental safety.

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: D7574 − 23
Standard Test Method for
Determination of Bisphenol A in Environmental Waters by
Liquid Chromatography/Tandem Mass Spectrometry
This standard is issued under the fixed designation D7574; 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 D3694 Practices for Preparation of Sample Containers and
for Preservation of Organic Constituents
1.1 This test method covers the determination of bisphenol
D3856 Guide for Management Systems in Laboratories
A (BPA) extracted from water utilizing solid phase extraction
Engaged in Analysis of Water
(SPE), separated using liquid chromatography (LC) and de-
D5847 Practice for Writing Quality Control Specifications
tected with tandem mass spectrometry (MS/MS). BPA is
for Standard Test Methods for Water Analysis
qualitatively and quantitatively determined by this method.
D5905 Practice for the Preparation of Substitute Wastewater
This test method adheres to multiple reaction monitoring
2.2 Other Documents:
(MRM) mass spectrometry.
40 CFR Part 136, Appendix B Definition and Procedure for
1.2 The values stated in SI units are to be regarded as
the Determination of the Method Detection Limit
standard. No other units of measurement are included in this
standard.
3. Terminology
1.3 The method detection limit (MDL) and reporting limit
3.1 Definitions:
(RL) for BPA are listed in Table 1.
3.1.1 For definitions of terms used in this standard, refer to
1.4 This standard does not purport to address all of the
Terminology D1129.
safety concerns, if any, associated with its use. It is the
3.2 Definitions of Terms Specific to This Standard:
responsibility of the user of this standard to establish appro-
3.2.1 environmental water, n—shall refer to water tested
priate safety, health, and environmental practices and deter-
using this method. See Section 5.
mine the applicability of regulatory limitations prior to use.
3.2.2 independent reference material, IRM, n—a material of
1.5 This international standard was developed in accor-
known purity and concentration obtained either from the
dance with internationally recognized principles on standard-
National Institute of Standards and Technology (NIST) or other
ization established in the Decision on Principles for the
reputable supplier; the IRM must be obtained from a different
Development of International Standards, Guides and Recom-
lot of material than is used for calibration.
mendations issued by the World Trade Organization Technical
3.3 Acronyms:
Barriers to Trade (TBT) Committee.
3.3.1 CCC, n—Continuing Calibration Check
2. Referenced Documents 3.3.2 IC, n—Initial Calibration
3.3.3 LC, n—Liquid Chromatography
2.1 ASTM Standards:
D1129 Terminology Relating to Water
3.3.4 LCS/LCSD, n—Laboratory Control Sample/
D1193 Specification for Reagent Water
Laboratory Control Sample Duplicate
D2777 Practice for Determination of Precision and Bias of
3.3.5 MDL, n—Method Detection Limit
Applicable Test Methods of Committee D19 on Water
3.3.6 MeOH, n—Methanol
-3
3.3.7 mM, n—millimolar, 1 × 10 moles/L
This test method is under the jurisdiction of ASTM Committee D19 on Water 3.3.8 MRM, n—Multiple Reaction Monitoring
and is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
3.3.9 MS/MSD, n—Matrix Spike/Matrix Spike Duplicate
Organic Substances in Water.
Current edition approved April 15, 2023. Published June 2023. Originally
3.3.10 NA, adj—Not Available
approved in 2009. Last previous edition approved in 2016 as D7574 – 16. DOI:
10.1520/D7574-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from U.S. Government Printing Office Superintendent of Documents,
Standards volume information, refer to the standard’s Document Summary page on 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
the ASTM website. www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7574 − 23
TABLE 1 MDL and Reporting Range
laminates for printed circuit boards, composites, paints,
A B
Analyte MDL (ng/L) Reporting Range (ng/L) adhesives, dental sealants, protective coatings and many other
Bisphenol A 5 20–600
products.
A
MDL determined following the Code of Federal Regulations, 40 CFR Part 136,
5.2 The environmental source of BPA is predominantly
Appendix B.
B
Lowest point of the reporting range, reporting limit, is calculated from the LV 1 from the decomposition of polycarbonate plastics and resins.
concentration calibration standard in Table 4. Fig. 1 displays the signal/noise ratio
BPA is not classified as bio-accumulative by the U.S. Environ-
at the reporting limit.
mental Protection Agency and will biodegrade. BPA has been
reported to have adverse effects in aquatic organisms and may
be released into environmental waters directly at trace levels
3.3.11 ND, n—non-detect
through landfill leachate and POTW effluents. This method has
3.3.12 P&A, n—Precision and Accuracy
been investigated for use with surface water and secondary and
tertiary POTW effluent samples therefore, it is applicable to
3.3.13 PPB, n—parts per billion
these matrices only. It has not been investigated for use with
3.3.14 PPT, n—parts per trillion
salt water or solid sample matrices.
3.3.15 QA, adj—Quality Assurance
6. Interferences
3.3.16 QC, adj—Quality Control
6.1 Method interferences may be caused by contaminants in
3.3.17 RL, n—Reporting Limit
solvents, reagents, glassware and other apparatus producing
3.3.18 RSD, n—Relative Standard Deviation
discrete artifacts or elevated baselines. The use of plastic
3.3.19 RT, n—Retention Time
supplies and equipment must be avoided because they may
3.3.20 SDS, n—Safety Data Sheets
contain BPA. All of these materials are routinely demonstrated
to be free from interferences by analyzing laboratory reagent
3.3.21 SRM, n—Single Reaction Monitoring
blanks under the same conditions as the samples.
3.3.22 SS, n—Surrogate Standard
6.2 All glassware is washed in hot water with a detergent,
3.3.23 TC, n—Target Compound
rinsed in hot water followed by distilled water. The glassware
-6
3.3.24 μM, n—micromolar, 1 × 10 moles/L
is then dried and heated in an oven at 250 °C for 15 min to
3.3.25 VOA, n—Volatile Organic Analysis
30 min. All glassware is subsequently cleaned with acetone,
then methanol. Detergents in plastic containers that contain
4. Summary of Test Method
BPA must not be used.
4.1 This is a performance based method and modifications
6.3 All reagents and solvents should be of pesticide residue
are allowed to improve performance.
purity or higher to minimize interference problems.
4.2 Solid phase extraction is used to extract water samples.
6.4 Matrix interferences may be caused by contaminants
4.2.1 Solid Phase Extraction—250 mL volume of sample
that are co-extracted from the sample. The extent of matrix
adjusted to pH 2 is extracted using a solid phase extraction
interferences can vary considerably from sample source to
cartridge. The resulting methyl tert-butyl ether (MTBE) extract
sample source, depending on variations of the sample matrix.
is solvent exchanged into methanol, concentrated to a volume
of 0.2 mL, brought to a final volume of 1 mL with water and
7. Apparatus
then analyzed by LC/MS/MS operated in the multiple reaction
7.1 LC/MS/MS System:
monitoring (MRM) mode.
7.1.1 Liquid Chromatography System—A complete LC sys-
4.3 The target compound, surrogate and internal standards
tem is needed in order to analyze samples. This should include
are identified by retention time and two SRM transitions. The
a sample injection system, a solvent pumping system capable
target analyte and surrogate are quantitated using the primary
of mixing solvents, a sample compartment capable of main-
SRM transitions utilizing internal standard calibration. The
taining required temperature and a temperature controlled
final report issued for each sample lists the concentration of
column compartment. A system that is capable of performing at
BPA and the bisphenol A (Ring-13C12) surrogate recovery.
the flows, pressures, controlled temperatures, sample volumes
and requirements of the standard may be used.
5. Significance and Use
7.1.1.1 Columns—Column to separate instrument back-
5.1 The first reported synthesis of BPA was by the reaction
ground (isolator): A short (2.1 mm × 50 mm) C8 or C18
of phenol with acetone by Zincke. BPA has become an
column stable at higher pH up to 12 and an analytical column.
important high volume industrial chemical used in the manu-
facture of polycarbonate plastic and epoxy resins. Polycarbon-
Additional information about BPA is available at http://www.bisphenol-a.org
ate plastic and resins are used in numerous products including
(2008).
electrical and electronic equipment, automobiles, sports and
A Waters ACQUITY UPLC (a trademark of the Waters Corporation, Milford,
safety equipment, reusable food and drink containers, electrical
MA) HSS T3, 1.8 μm, 2.1 mm × 50 mm column was used, if you are aware of an
alternative column that meets the performance of the standard, please provide this
information to ASTM International Headquarters. Your comments will receive
4 1
Zincke, T., 1905, “Mittheilungen aus dem chemischen Laboratorium der careful consideration at a meeting of the responsible technical committee, which
Universitat Marburg,” Justus Leibigs Annals Chemie, Vol. 343, pages 75–79. you may attend.
D7574 − 23
7.1.1.2 Tandem Mass Spectrometer (MS/MS) System—A 8.14 Solid Phase Extraction Cartridges —An SPE car-
MS/MS system capable of MRM analysis. A system that is tridge suitable for the extraction of BPA.
capable of performing at the requirements in this standard may
NOTE 1—If plastic cartridges are used, BPA may be found, therefore it
be used.
is advisable that the cartridges be lot certified BPA-free. BPA may adhere
to plastic cartridges which will cause lower recoveries. Glass cartridges
7.2 SPE Vacuum Manifold System—A solid phase extraction
have a much lower adhesive tendency to BPA and should not contain BPA
vacuum manifold or similar may be utilized.
in the packing or support materials, therefore glass cartridges should be
used.
7.3 Organic solvent evaporation device.
9. Hazards
8. Reagents and Materials
9.1 Normal laboratory safety applies to this method. Ana-
8.1 Purity of Reagents—High Performance Liquid Chroma-
lysts should wear safety glasses, gloves and lab coats when
tography (HPLC) pesticide residue analysis and spectropho-
working with acids. Analysts should review the Safety Data
tometry grade chemicals must be used in all tests. Unless
Sheets (SDS) for all reagents used in this method.
indicated otherwise, it is intended that all reagents must
conform to the specifications of the Committee on Analytical
10. Sample Collection, Preservation, and Storage
Reagents of the American Chemical Society. Other reagent
10.1 Sampling—Grab samples must be collected in amber
grades may be used, provided it is first ascertained that they are
glass bottles, minimum size of 250 mL. Rinsing of the bottle
of sufficiently high purity to permit their use without affecting
with 10 % methanol in water, water, and 10 % methanol/2 %
the accuracy of the measurement.
NH OH in water is required in order to get quantitative transfer
8.2 Purity of Water—Unless otherwise indicated, references
of the sample into the SPE cartridge and extraction process.
to water must be understood to mean reagent water conforming
BPA tends to adsorb to surfaces and rinsing will allow
to Type I of Specification D1193. It must be demonstrated that
optimum recoveries. Conventional sampling practices should
this water does not contain contaminants at concentrations
be followed. Refer to Guide D3856 and Practices D3694.
sufficient to interfere with the analysis.
Pre-cleaned bottles demonstrated to be free of interferences
8.3 Gases—Ultrapure nitrogen and argon.
may be used. Automatic sampling equipment should be free
from plastics and tubing that contains BPA and other potential
8.4 Acetonitrile (CAS # 75-05-8).
sources of contamination or adhesion.
8.5 Methanol (CAS # 67-56-1).
10.2 Preservation—Adjust sample to pH 2 with concen-
8.6 2-Propanol (CAS # 67-63-0).
trated HCl at time of collection. Store samples between above
8.7 Acetone (CAS # 67-64-1).
freezing and 6 °C from the time of collection until extraction.
Extract the sample within 7 days of collection and completely
8.8 Methyl tert-butyl ether (MTBE, CAS # 1634-04-4).
analyze within 14 days of extraction.
8.9 Ammonium Hydroxide (CAS # 1336-21-6) (ACS re-
agent grade or better).
11. Preparation of LC/MS/MS
8.10 Concentrated HCl (CAS # 7647-01-0).
11.1 LC Set Up for Liquid Chromatography BPA Isolator
Column for Low Level BPA Analysis—BPA may be a contami-
8.11 Bisphenol A (BPA, 2,2’-Bis(4-hydroxyphenyl)propane,
nant in the LC system due to the widespread use of plastic parts
CAS # 80-05-7).
and tubing. Incorporating an isolator column into the LC
8.12 Bisphenol A (Ring-13C12) represents C labeled
system allows for the low level analysis of BPA and reduces
bisphenol A where all ring carbon atoms are uniformly
the risk of high biased data. The LC conditions in this standard
labeled C.
allow for the BPA in the system to elute 0.4 min later than BPA
8.12.1 Bisphenol A (Ring-13C12) is used as a surrogate in
from the sample injection. The BPA concentration found in the
this standard.
LC system used was below the MDL of the standard but an
8.13 Bisphenol A (Propane-D6) represents deuterium la-
isolator column must be incorporated to eliminate the risk of
beled bisphenol A where the 2 methyl moieties contain all H.
high bias. An isolator column was placed after the mixer of two
8.13.1 Bisphenol A (Propane-D6) is used as an internal
solvent feeds and before the port of the multi-port valve which
standard in this method.
contains the injection loop. No plastics are used in the system
at this point ensuring that the first eluted BPA peak is only from
the BPA in the sample and not the LC system. This placement
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
allows for the impurities in the LC, such as BPA, to be trapped
Standard-Grade Reference Materials, American Chemical Society, Washington,
by the isolator column and elute after the BPA from the sample.
DC. For suggestions on the testing of reagents not listed by the American Chemical
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
copeial Convention, Inc. (USPC), Rockville, MD. A Waters Oasis (a trademark of the Waters Corporation, Milford, MA) HLB 5cc
A source for the labeled BPA standards is Cambridge Isotope Laboratories, 50 (200 mg) LP Glass Cartridges were used, if you are aware of an alternative column
Frontage Road, Andover, MA 01810-5413. If you are aware of alternative suppliers, that meets the performance of the standard, please provide this information to
please provide this information to ASTM International Headquarters. Your com- ASTM International Headquarters. Your comments will receive careful consider-
ments will receive careful consideration at a meeting of the responsible technical ation at a meeting of the responsible technical committee, which you may attend.
committee, which you may attend.
D7574 − 23
Consult with the instrument manufacturer for the proper 11.5.1 In order to acquire the maximum number of data
placement of the isolator column for optimum results. points per MRM channel with optimum sensitivity, the scan,
delay and dwell times may be changed and optimized accord-
11.2 LC Analytical Column—C18 column or equivalent.
ing to the instrument. The SRM chromatograms displayed in
11.3 LC Operating Conditions—Injections of all calibration
Fig. 1 contain 17 data points across the peak at the reporting
standards and samples are made at a 50 μL volume using a full
limit. Each peak requires at least 10 scans per peak for
loop injection. If a 50 μL volume loop is installed in the LC, a
adequate quantitation. This standard contains only one target
“full loop” mode is the preferred technique when performing
compound, one surrogate and one internal standard which are
fast, quantitative analyses. This mode should be used whenever
in one MRM experiment window. For details regarding reten-
accuracy and precision are the primary concerns. Specific
tion times and SRM transitions cone and collision energies,
instrument manufacturer specifications should be followed to
refer to Table 3.
achieve maximum performance. The first sample analyzed
after the calibration curve is a blank to ensure there is no
12. Calibration and Standardization
carry-over. The gradient conditions for the liquid chromato-
12.1 In order to be certain that analytical values obtained
graph are shown in Table 2.
using this test method are valid and accurate within the
11.4 LC Auto Sampler Conditions—Wash Solvents: Weak
confidence limits of the test, the following procedures de-
wash is 1.2 mL of 5 % methanol in water. Strong wash is 1 mL
scribed below must be followed when performing the test
of 30 % acetonitrile/30 % methanol/30 % 2-propanol/10 %
method.
water. The strong wash solvent is needed to eliminate carry-
over between injections. The weak wash is used to remove the
12.2 Calibration and Standardization—To calibrate the
strong wash solvent. Specific instrument manufacturer speci-
instrument, analyze eight calibration standards containing the
fications should be followed in order to eliminate sample
eight concentration levels of BPA and BPA (Ring-13C12)
carry-over in the analysis of BPA. Temperatures: Column
surrogate with a constant concentration of BPA (Propane-D6)
40 °C, Sample compartment 15 °C. Seal Wash: 5 min.
Internal Standard prior to analysis as shown in Table 4. A
11.5 Mass Spectrometer Parameters—The instrument uti- calibration stock standard solution is prepared from standard
materials or purchased as certified solutions. Stock Standard
lized may require different settings. Variable parameters de-
pending on analyte are shown in Table 3. Solution A (Level 8) containing BPA and BPA (Ring-13C12) is
prepared at Level 8 concentration and aliquots of that solution
The instrument is set in the Electrospray source setting.
Capillary Voltage: 3.5 kV
are diluted to prepare Levels 1 through 7. Stock Internal
Cone: ESI Negative 40 Volts (Table 3)
Standard Solution B is made at a concentration of 7.5 ppm
Extractor: 3 Volts
bisphenol A (Propane-D6) in methanol. The following steps
RF Lens: 0.3 Volts
Source Temperature: 120 °C
will produce standards with the concentrations values shown in
Desolvation Temperature: 400 °C
Table 4. The analyst is responsible for recording initial
Desolvation Gas Flow: 800 L/h
component weights carefully when working with the pure
Cone Gas Flow: 20 L/h
Low Mass Resolution 1:14 materials, and correctly carrying the weights through the
High Mass Resolution 1:14
dilution calculations.
Ion Energy 1:1
Entrance Energy: –1 12.2.1 Prepare Stock Standard Solution A (Level 8) by
Collision Energy: Variable depending on analyte (Table 3)
adding to a 25 mL volumetric flask individual solutions of the
Exit Energy: 0
following: 37.5 μL of 100 ppm BPA in methanol and 37.5 μL
Low Mass Resolution 2:14
of 100 ppm BPA (Ring-13C12) in acetonitrile then dilute to
High Mass Resolution 2:14
Ion Energy 2:1
25 mL with 90 % water/10 % methanol to ensure the BPA
Multiplier: 650
remains in solution and does not adhere to the walls of the
–3
Collision Cell Pirani Gauge: 7 × 10 Torr
–5
Analyser Penning Gauge: 3 × 10 Torr flask. The 100 ppm BPA stock solution is made in methanol to
Inter-Channel Delay: 0.02 s
ensure solubility. The 100 ppm BPA (Ring-13C12) in acetoni-
Inter-Scan Delay: 0.02 s
trile is purchased. The preparation of the Level 8 standard can
Repeats: 1
Span: 0 Daltons be accomplished using different volumes and concentrations of
Dwell: 0.05 s
stock solutions as is accustomed in the individual laboratory.
TABLE 2 Gradient Conditions for Liquid Chromatography
Time Flow Percent Water/5 Percent Methanol/5
(Minutes) (μL/Minute) mmolar mmolar
NH OH NH OH
4 4
0 300 100 0
1 300 100 0
2 250 75 25
5 250 25 75
6 250 25 75
7 300 0 100
9 300 0 100
10 300 100 0
12 300 100 0
D7574 − 23
TABLE 3 Retention Times, SRM transitions, SRM Ratios and Analyte-Specific Mass Spectrometer Parameters
Analyte Primary/Confirmatory Retention time Cone Voltage Collision SRM Mass Primary/
(min) (Volts) Energy transition Confirmatory
(eV) (Parent > Product) SRM Area Ratio
Primary –40 19 227 > 211.9
Bisphenol A 5.9 2.97
Confirmatory –40 25 227 > 132.8
Primary –40 19 239 > 224
Bisphenol A (Ring-13C12) Surrogate 5.9 3.02
Confirmatory –40 25 239 >138.8
Primary –40 19 233 > 214.9
Bisphenol A (Propane-D6) Internal Standard 5.9 3.31
Confirmatory –40 25 233 > 137.7
FIG. 1 Example SRM Chromatograms Signal/Noise at Reporting Limit
TABLE 4 Concentrations of Calibration Standards (ppb)
12.2.2 Aliquots of Stock Standard Solution A and Stock
Analyte/ LV 1 LV 2 LV 3 LV 4 LV 5 LV 6 LV 7 LV 8
Internal Standard Solution B are then diluted with 90 %
Surrogate/
water/10 % methanol to prepare the desired calibration levels
Internal
in 2 mL amber LC vials. The calibration vials must be used
Standard
BPA 5 10 25 50 75 100 125 150
within 24 h to ensure optimum results. Stock calibration
BPA (Ring- 5 10 25 50 75 100 125 150
standards are routinely replaced every six months if not
13C12)
Surrogate previously discarded for QC criteria failure.
BPA (Propane- 75 75 75 75 75 75 75 75
12.2.3 Inject each standard and obtain a chromatogram for
D6)
each one. An internal standard calibration technique is used
Internal
Standard
monitoring the primary and c
...

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: D7574 − 16 D7574 − 23
Standard Test Method for
Determination of Bisphenol A in Environmental Waters by
Liquid Chromatography/Tandem Mass Spectrometry
This standard is issued under the fixed designation D7574; 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 procedure test method covers the determination of bisphenol A (BPA) extracted from water utilizing solid phase
extraction (SPE), separated using liquid chromatography (LC) and detected with tandem mass spectrometry (MS/MS). BPA is
qualitatively and quantitatively determined by this method. This test method adheres to multiple reaction monitoring (MRM) mass
spectrometry.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 The method detection limit (MDL) and reporting limit (RL) for BPA are listed in Table 1.
1.4 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 and healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use.
1.5 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:
D1129 Terminology Relating to Water
D1193 Specification for Reagent Water
D2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
D3694 Practices for Preparation of Sample Containers and for Preservation of Organic Constituents
D3856 Guide for Management Systems in Laboratories Engaged in Analysis of Water
D5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
D5905 Practice for the Preparation of Substitute Wastewater
2.2 Other Documents:
The Code of Federal Regulations40 CFR Part 136, Appendix B 40 CFR Part 136, Appendix BDefinition and Procedure for the
Determination of the Method Detection Limit
This test method is under the jurisdiction of ASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
Organic Substances in Water.
Current edition approved Feb. 1, 2016April 15, 2023. Published March 2016June 2023. Originally approved in 2009. Last previous edition approved in 20092016 as
D7574D7574 – 16. – 09. DOI: 10.1520/D7574-16.DOI: 10.1520/D7574-23.
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.
Available from U.S. Government Printing Office Superintendent of Documents, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7574 − 23
TABLE 1 MDL and Reporting Range
A B
Analyte MDL (ng/L) Reporting Range (ng/L)
Bisphenol A 5 20–600
A
MDL determined following the Code of Federal Regulations, 40CFR 40 CFR Part
136, Appendix B.
B
Lowest point of the reporting range, reporting limit, is calculated from the LV 1
concentration calibration standard in Table 4. Fig. 1 displays the signal/noise ratio
at the reporting limit.
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this standard, refer to Terminology D1129.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 environmental water, n—shall refer to water tested using this method. See Section 5.
3.2.2 independent reference material, IRM, n—a material of known purity and concentration obtained either from the National
Institute of Standards and Technology (NIST) or other reputable supplier. The IRM shallsupplier; the IRM must be obtained from
a different lot of material than is used for calibration.
3.3 Acronyms:
3.3.1 CCC, n—Continuing Calibration Check
3.3.2 IC, n—Initial Calibration
3.3.3 LC, n—Liquid Chromatography
3.3.4 LCS/LCSD, n—Laboratory Control Sample/Laboratory Control Sample Duplicate
3.3.5 MDL, n—Method Detection Limit
3.3.6 MeOH, n—Methanol
-3
3.3.7 mM, n—millimolar, 1 × 10 moles/L
3.3.8 MRM, n—Multiple Reaction Monitoring
3.3.9 MS/MSD, n—Matrix Spike/Matrix Spike Duplicate
3.3.10 NA, adj—Not Available
3.3.11 ND, n—non-detect
3.3.12 P&A, n—Precision and Accuracy
3.3.13 PPB, n—parts per billion
3.3.14 PPT, n—parts per trillion
3.3.15 QA, adj—Quality Assurance
3.3.16 QC, adj—Quality Control
D7574 − 23
3.3.17 RL, n—Reporting Limit
3.3.18 RSD, n—Relative Standard Deviation
3.3.19 RT, n—Retention Time
3.3.20 SDS, n—Safety Data Sheets
3.3.21 SRM, n—Single Reaction Monitoring
3.3.22 SS, n—Surrogate Standard
3.3.23 TC, n—Target Compound
-6
3.3.24 μM, n—micromolar, 1 × 10 moles/L
3.3.25 VOA, n—Volatile Organic Analysis
4. Summary of Test Method
4.1 This is a performance based method and modifications are allowed to improve performance.
4.2 Solid phase extraction is used to extract water samples.
4.2.1 Solid Phase Extraction—250 milliliter 250 mL volume of sample adjusted to pH 2 is extracted using a solid phase extraction
cartridge. The resulting methyl tert-butyl ether (MTBE) extract is solvent exchanged into methanol, concentrated to a volume of
0.2 mL, brought to a final volume of 1 mL with water and then analyzed by LC/MS/MS operated in the multiple reaction
monitoring (MRM) mode.
4.3 The target compound, surrogate and internal standards are identified by retention time and two SRM transitions. The target
analyte and surrogate are quantitated using the primary SRM transitions utilizing internal standard calibration. The final report
issued for each sample lists the concentration of BPA and the bisphenol A (Ring-13C12) surrogate recovery.
5. Significance and Use
5.1 The first reported synthesis of BPA was by the reaction of phenol with acetone by Zincke. BPA has become an important high
volume industrial chemical used in the manufacture of polycarbonate plastic and epoxy resins. Polycarbonate plastic and resins
are used in numerous products including electrical and electronic equipment, automobiles, sports and safety equipment, reusable
food and drink containers, electrical laminates for printed circuit boards, composites, paints, adhesives, dental sealants, protective
coatings and many other products.
5.2 The environmental source of BPA is predominantly from the decomposition of polycarbonate plastics and resins. BPA is not
classified as bio-accumulative by the U.S. Environmental Protection Agency and will biodegrade. BPA has been reported to have
adverse effects in aquatic organisms and may be released into environmental waters directly at trace levels through landfill leachate
and POTW effluents. This method has been investigated for use with surface water and secondary and tertiary POTW effluent
samples therefore, it is applicable to these matrices only. It has not been investigated for use with salt water or solid sample
matrices.
6. Interferences
6.1 Method interferences may be caused by contaminants in solvents, reagents, glassware and other apparatus producing discrete
Zincke, T., 1905, “Mittheilungen aus dem chemischen Laboratorium der Universitat Marburg,” Justus Leibigs Annals Chemie, Vol. 343, pages 75–79.
Additional information about BPA is available at http://www.bisphenol-a.org (2008).
D7574 − 23
artifacts or elevated baselines. The use of plastic supplies and equipment must be avoided because they may contain BPA. All of
these materials are routinely demonstrated to be free from interferences by analyzing laboratory reagent blanks under the same
conditions as the samples.
6.2 All glassware is washed in hot water with a detergent, rinsed in hot water followed by distilled water. The glassware is then
dried and heated in an oven at 250ºC for 15 to 30 minutes. 250 °C for 15 min to 30 min. All glassware is subsequently cleaned
with acetone, then methanol. Detergents in plastic containers that contain BPA must not be used.
6.3 All reagents and solvents should be of pesticide residue purity or higher to minimize interference problems.
6.4 Matrix interferences may be caused by contaminants that are co-extracted from the sample. The extent of matrix interferences
can vary considerably from sample source to sample source, depending on variations of the sample matrix.
7. Apparatus
7.1 LC/MS/MS System:
7.1.1 Liquid Chromatography System—A complete LC system is needed in order to analyze samples. This should include a sample
injection system, a solvent pumping system capable of mixing solvents, a sample compartment capable of maintaining required
temperature and a temperature controlled column compartment. A system that is capable of performing at the flows, pressures,
controlled temperatures, sample volumes and requirements of the standard may be used.
7.1.1.1 Columns—Column to separate instrument background (isolator): A short (2.1(2.1 mm × 50 mm) C8 or C18 column stable
at higher pH up to 12 and an analytical column.
7.1.1.2 Tandem Mass Spectrometer (MS/MS) System—A MS/MS system capable of MRM analysis. A system that is capable of
performing at the requirements in this standard may be used.
7.2 SPE Vacuum Manifold SystemSystem——Supelco Visiprep A solid phase extraction vacuum manifold or similar may be
utilized.
7.3 Organic solvent evaporation device.
8. Reagents and Materials
8.1 Purity of Reagents—High Performance Liquid Chromatography (HPLC) pesticide residue analysis and spectrophotometry
grade chemicals shallmust be used in all tests. Unless indicated otherwise, it is intended that all reagents shallmust conform to the
specifications of the Committee on Analytical Reagents of the American Chemical Society. Other reagent grades may be used,
provided it is first ascertained that they are of sufficiently high purity to permit their use without affecting the accuracy of the
measurement.
8.2 Purity of Water—Unless otherwise indicated, references to water shallmust be understood to mean reagent water conforming
to Type I of Specification D1193. It must be demonstrated that this water does not contain contaminants at concentrations sufficient
to interfere with the analysis.
A Waters ACQUITY UPLC (a trademark of the Waters Corporation, Milford, MA) HSS T3, 1.8 μm, 2.12.1 mm × 50 mm column, or equivalent, was found suitable for
use.column was used, if you are aware of an alternative column that meets the performance of the standard, please provide this information to ASTM International
Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.
A Waters Quattro Premier (a trademark of the Waters Corporation, Milford, MA) mass spectrometer, or equivalent, was found suitable for use.
A Supelco Visiprep (a trademark of Sigma-Aldrich Co., LLC, St. Louis, MO) was found suitable to use, any SPE extraction manifold may be used.
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
Materials, American Chemical Society, Washington, DC. For Suggestionssuggestions on the testing of reagents not listed by the American Chemical Society, see
AnnualAnalar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial
Convention, Inc. (USPC), Rockville, MD.
A source for the labeled BPA standards is Cambridge Isotope Laboratories, 50 Frontage Road, Andover, MA 01810-5413. If you are aware of alternative suppliers, please
provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which
you may attend.
D7574 − 23
8.3 Gases—Ultrapure nitrogen and argon.
8.4 Acetonitrile (CAS # 75-05-8).
8.5 Methanol (CAS # 67-56-1).
8.6 2-Propanol (CAS # 67-63-0).
8.7 Acetone (CAS # 67-64-1).
8.8 Methyl tert-butyl ether (MTBE, CAS # 1634-04-4).
8.9 Ammonium Hydroxide (CAS # 1336-21-6) (ACS reagent grade or better).
8.10 Concentrated HCl (CAS # 7647-01-0).
8.11 Bisphenol A (BPA, 2,2’-Bis(4-hydroxyphenyl)propane, CAS # 80-05-7).
13 13
8.12 Bisphenol A (Ring-13C12) represents C labeled bisphenol A where all ring carbon atoms are uniformly labeled C.
8.12.1 Bisphenol A (Ring-13C12) is used as a surrogate in this standard.
8.13 Bisphenol A (Propane-D6) represents deuterium labeled bisphenol A where the 2 methyl moieties contain all H.
8.13.1 Bisphenol A (Propane-D6) is used as an internal standard in this method.
8.14 Solid Phase Extraction Cartridges—Cartridges —An SPE cartridge suitable for the extraction of BPA.
NOTE 1—If plastic cartridges are used, BPA may be found, therefore it is advisable that the cartridges be lot certified BPA-free. BPA may adhere to plastic
cartridges which will cause lower recoveries. Glass cartridges have a much lower adhesive tendency to BPA and should not contain BPA in the packing
or support materials, therefore glass cartridges should be used.
9. Hazards
9.1 Normal laboratory safety applies to this method. Analysts should wear safety glasses, gloves and lab coats when working with
acids. Analysts should review the Safety Data Sheets (SDS) for all reagents used in this method.
10. Sample Collection, Preservation, and Storage
10.1 Sampling—Grab samples must be collected in 250 mL amber glass bottles. amber glass bottles, minimum size of 250 mL.
Rinsing of the bottle with 10 % methanol in water, water, and 10 % methanol/2 % NH OH in water is required in order to get
quantitative transfer of the sample into the SPE cartridge and extraction process. BPA tends to adsorb to surfaces and rinsing will
allow optimum recoveries. Conventional sampling practices should be followed. Refer to Guide D3856 and Practices D3694.
Pre-cleaned bottles demonstrated to be free of interferences may be used. Automatic sampling equipment should be free from
plastics and tubing that contains BPA and other potential sources of contamination or adhesion.
10.2 Preservation—Adjust sample to pH 2 with concentrated HCl at time of collection. Store samples between 0ºC and 6ºCabove
freezing and 6 °C from the time of collection until extraction. Extract the sample within 7 days of collection and completely
analyze within 14 days of extraction.
A Waters Oasis (a trademark of the Waters Corporation, Milford, MA) HLB 5cc (200 mg) LP Glass Cartridges, or equivalent, have been found suitable for use.Cartridges
were used, if you are aware of an alternative column that meets the performance of the standard, please provide this information to ASTM International Headquarters. Your
comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.
D7574 − 23
11. Preparation of LC/MS/MS
11.1 LC Set Up for Liquid Chromatography BPA Isolator Column for Low Level BPA Analysis—BPA may be a contaminant in the
LC system due to the widespread use of plastic parts and tubing. Incorporating an isolator column into the LC system allows for
the low level analysis of BPA and reduces the risk of high biased data. The LC conditions in this standard allow for the BPA in
the system to elute 0.4 minutesmin later than BPA from the sample injection. The BPA concentration found in the LC system used
was below the MDL of the standard but an isolator column must be incorporated to eliminate the risk of high bias. An isolator
column was placed after the mixer of two solvent feeds and before the port 5 of the multi-port valve which contains the injection
loop. No plastics are used in the system at this point ensuring that the first eluted BPA peak is only from the BPA in the sample
and not the LC system. This placement allows for the impurities in the LC, such as BPA, to be trapped by the isolator column and
elute after the BPA from the sample. If a different LC system is used, consult Consult with the instrument manufacturer for the
proper placement of the isolator column for optimum results.
11.2 LC Analytical ColumnColumn——C18 column or equivalent.
11.3 LC Operating Conditions—Injections of all calibration standards and samples are made at a 50 μL volume using a full loop
injection. If a 50 μL volume loop is installed in yourthe LC, a “full loop” mode is the preferred technique when performing fast,
quantitative analyses. This mode should be used whenever accuracy and precision are the primary concerns. Specific instrument
manufacturer specifications should be followed to achieve maximum performance. The first sample analyzed after the calibration
curve is a blank to ensure there is no carry-over. The gradient conditions for the liquid chromatograph are shown in Table 2.
11.4 LC Auto Sampler Conditions—Wash Solvents: Weak wash is 1.2 mL of 5 % methanol in water. Strong wash is 1 mL of 30 %
acetonitrile/30 % methanol/30 % 2-propanol/10 % water. The strong wash solvent is needed to eliminate carry-over between
injections. The weak wash is used to remove the strong wash solvent. Specific instrument manufacturer specifications should be
followed in order to eliminate sample carry-over in the analysis of BPA. Temperatures: Column 40°C,40 °C, Sample compartment
15°C.15 °C. Seal Wash: 5 minutes.min.
11.5 Mass Spectrometer Parameters—YourThe instrument utilized may require different settings. Variable parameters depending
on analyte are shown in Table 3.
The instrument is set in the Electrospray source setting.
Capillary Voltage: 3.5 kV
Cone: ESI Negative 40 Volts (Table 3)
Extractor: 3 Volts
RF Lens: 0.3 Volts
Source Temperature: 120°C
Source Temperature: 120 °C
Desolvation Temperature: 400°C
Desolvation Temperature: 400 °C
Desolvation Gas Flow: 800 L/hr
Desolvation Gas Flow: 800 L/h
Cone Gas Flow: 20 L/hr
Cone Gas Flow: 20 L/h
Low Mass Resolution 1:14
High Mass Resolution 1:14
Ion Energy 1:1
Entrance Energy: –1
Collision Energy: Variable depending on analyte (Table 3)
Exit Energy: 0
TABLE 2 Gradient Conditions for Liquid Chromatography
Time Flow Percent Water/5 Percent Methanol/5
(Minutes) (μL/Minute) mmolar mmolar
NH OH NH OH
4 4
0 300 100 0
1 300 100 0
2 250 75 25
5 250 25 75
6 250 25 75
7 300 0 100
9 300 0 100
10 300 100 0
12 300 100 0
D7574 − 23
TABLE 3 Retention Times, SRM transitions, SRM Ratios and Analyte-Specific Mass Spectrometer Parameters
Analyte Primary/Confirmatory Retention time Cone Voltage Collision SRM Mass Primary/
(min) (Volts) Energy transition Confirmatory
(eV) (Parent > Product) SRM Area Ratio
Primary –40 19 227 > 211.9
Bisphenol A 5.9 2.97
Confirmatory –40 25 227 > 132.8
Primary –40 19 239 > 224
Bisphenol A (Ring-13C12) Surrogate 5.9 3.02
Confirmatory –40 25 239 >138.8
Primary –40 19 233 > 214.9
Bisphenol A (Propane-D6) Internal Standard 5.9 3.31
Confirmatory –40 25 233 > 137.7
Low Mass Resolution 2:14
High Mass Resolution 2:14
Ion Energy 2:1
Multiplier: 650
–3
Collision Cell Pirani Gauge: 7 × 10 Torr
–5
Analyser Penning Gauge: 3 × 10 Torr
Inter-Channel Delay: 0.02 seconds
Inter-Channel Delay: 0.02 s
Inter-Scan Delay: 0.02 seconds
Inter-Scan Delay: 0.02 s
Repeats: 1
Span: 0 Daltons
Dwell: 0.05 seconds
Dwell: 0.05 s
11.5.1 In order to acquire the maximum number of data points per MRM channel with optimum sensitivity, the scan, delay and
dwell times may be changed and optimized according to yourthe instrument. The SRM chromatograms displayed in Fig. 1 contain
FIG. 1 Example SRM Chromatograms Signal/Noise at Reporting Limit
D7574 − 23
17 data points across the peak at the reporting limit. Each peak requires at least 10 scans per peak for adequate quantitation. This
standard contains only one target compound, one surrogate and one internal standard which are in one MRM experiment window.
For details regarding retention times and SRM transitions cone and collision energies, refer to Table 3.
12. Calibration and Standardization
12.1 In order to be certain that analytical values obtained using this test method are valid and accurate within the confidence limits
of the test, the following procedures described below must be followed when performing the test method.
12.2 Calibration and Standardization—To calibrate the instrument, analyze eight calibration standards containing the eight
concentration levels of BPA and BPA (Ring-13C12) surrogate with a constant concentration of BPA (Propane-D6) Internal
Standard prior to analysis as shown in Table 4. A calibration stock standard solution is prepared from standard materials or
purchased as certified solutions. Stock Standard Solution A (Level 8) containing BPA and BPA (Ring-13C12) is prepared at Level
8 concentration and aliquots of that solution are diluted to prepare Levels 1 through 7. Stock Internal Standard Solution B is made
at a concentration of 7.5 ppm bisphenol A (Propane-D6) in methanol. The following steps will produce standards with the
concentrations values shown in Table 4. The analyst is responsible for recording initial component weights carefully when working
with the pure materials, and correctly carrying the weights through the dilution calculations.
12.2.1 Prepare Stock Standard Solution A (Level 8) by adding to a 25 mL 25 mL volumetric flask individual solutions of the
following: 37.5 μL 37.5 μL of 100 ppm BPA in methanol and 37.5 μL 37.5 μL of 100 ppm BPA (Ring-13C12) in acetonitrile then
dilute to 25 mL 25 mL with 90 % water/10 % methanol to ensure the BPA remains in solution and does not adhere to the walls
of the flask. The 100 ppm BPA stock solution is made in methanol to ensure solubility. The 100 ppm BPA (Ring-13C12) in
acetonitrile is purchased. The preparation of the Level 8 standard can be accomplished using different volumes and concentrations
of stock solutions as is accustomed in the individual laboratory. Depending on the stock concentrations prepared, the solubility at
that concentration will have to be ensured.
12.2.2 Aliquots of Stock Standard Solution A and Stock Internal Standard Solution B are then diluted with 90 % water/10 %
methanol to prepare the desired calibration levels in 2 mL amber LC vials. The calibration vials must be used within 24 hoursh
to ensure optimum results. Stock calibration standards are routinely replaced every six months if not previously discarded for QC
criteria failure.
12.2.3 Inject each standard and obtain a chromatogram for each one. An internal standard calibration technique is used monitoring
the primary and confirmatory SRM transition of each analyte. Calibration software is utilized to conduct the quantitation of the
target analyte and surrogate using the primary SRM transition. The ratio of th
...