ASTM D8024-23

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: D8024 − 16 D8024 − 23
Standard Test Method for
Determination of (Tri-n-butyl)-n-tetradecylphosphonium
chloride (TTPC) in Water by Multiple Reaction Monitoring
Liquid Chromatography/Mass Spectrometry (LC/MS/MS)
This standard is issued under the fixed designation D8024; 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 covers the determination of (Tri-n-butyl)-n-tetradecylphosphonium chloride (TTPC) in water by dilution with
acetone, filtration and analysis by liquid chromatography/tandem mass spectrometry. This test method is not amenable for the
analysis of isomeric mixtures of Tributyl-tetradecylphosphonium chloride. TTPC is a biocide that strongly adsorbs to soils. The
water samples are prepared in a solution of 75 % acetone and 25 % water because TTPC has an affinity for surfaces and particles.
The reporting range for this method is from 100–4000100 ng ng/L. ⁄L to 4000 ng ⁄L. This analyte is qualitatively and quantitatively
determined by this method. This test method adheres to multiple reaction monitoring (MRM) mass spectrometry.
1.2 A full collaborative study to meet the requirements of Practice D2777 has not been completed. This test method contains
single-operator precision and bias based on single-operator data. Publication of standards that have not been fully validated is done
to make the current technology accessible to users of standards, and to solicit additional input from the user community.
3 4
1.3 The Method Detection Limit (MDL) and Reporting Range for the target analyte are listed in Table 1.
1.3.1 The reporting limit in this test method is the minimum value below which data are documented as non-detects. Analyte
detections between the method detection limit and the reporting limit are estimated concentrations and are not reported following
this test method. The reporting limit is calculated from the concentration of the Level 1 calibration standard as shown in Table 4
for TTPC after taking into account a 2.5 mL water sample volume and a final diluted sample volume of 10 mL (75 % acetone/25
% water). The final solution volume is 10 mL because a 7.5 mL volume of acetone is added to each 2.5 mL water sample which
is shaken and filtered.
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
standard.
1.5 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 D19 on Water and is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
Organic Substances in Water.
Current edition approved June 1, 2016April 15, 2023. Published August 2016May 2023. Originally approved in 2016. Last previous edition approved in 2016 as
D8024 – 16. DOI: 10.1520/D8024-16.10.1520/D8024-23.
More information on TTPC can be found at http://www.buruenergy.com/wp-content/uploads/BE-Environmental-Properties-of-Proposed-Biocide-BE-91.pdf (2014) and
http://iaspub.epa.gov/sor_internet/registry/substreg/searchandretrieve/advancedsearch/externalSearch.do?p_type=CASNO&p=81741-28-8 (2014).
The MDL is determined following the Code of Federal Regulations, 40 CFR Part 136, Appendix B, as a guide. A detailed process determining the MDL is explained
in the reference and is beyond the scope of this test method to be explained here.
Reporting range concentration is calculated from Table 4 concentrations assuming a 50 μL injection of the Level 1 calibration standard for TTPC, and the highest level
calibration standard with a 10 mL final diluted sample volume starting with a 2.5 mL water sample. Volume variations will change the reporting limit and ranges.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8024 − 23
TABLE 1 Method Detection Limit and Reporting Range
MDL Reporting Range
Analyte
(ng/L) (ng/L)
TTPC 13 100–4000
1.6 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
D3856 Guide for Management Systems in Laboratories Engaged in Analysis of Water
D4841 Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic Constituents
D5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
E2554 Practice for Estimating and Monitoring the Uncertainty of Test Results of a Test Method Using Control Chart Techniques
2.2 Other Standards:
40 CFR Part 136, Appendix B Definition and Procedure for the Determination of the Method Detection Limit
EPA Publication SW-846 Test Methods for Evaluating Solid Waste, Physical/Chemical Methods
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 reporting limit, RL, n—the minimum concentration below which data are documented as non-detects.
3.2.2 reporting limit check sample, RLCS, n—a sample used to ensure that if the analyte was present at the reporting limit, it would
be confidently identified.
3.2.3 batch QC, n—all the quality control samples and standards included in an analytical procedure.
3.2.4 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.
3.2.4.1 Discussion—
The IRM shallmust 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 CRW, n—Chicago River Water
3.3.3 IC, n—Initial Calibration
3.3.4 LC, n—Liquid Chromatography
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from U.S. Government Printing Office, Superintendent of Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://www.access.gpo.gov.
Available from United States Environmental Protection Agency (EPA), William Jefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460,
http://www.epa.gov.
D8024 − 23
TABLE 2 Gradient Conditions for Liquid Chromatography
Percent
Time Flow Percent Percent
400 mM Ammonium Acetate
(min) (mL/min) 95 % Water: 5 % Acetonitrile Acetonitrile
(95 % Water: 5 % Acetonitrile)
0 0.3 95 0 5
1 0.3 95 0 5
4 0.4 0 95 5
11 0.4 0 95 5
12 0.4 95 0 5
15 0.4 95 0 5
TABLE 3 Retention Time, SRM Ions, and Analyte-Specific Mass Spectrometer Parameters
Retention Primary/
Primary/ SRM Cone Collision
Chemical Time Confirmatory
Confirmatory Transition (V) (eV)
(minutes) SRM Area Ratio
Primary (Quantitation) 40 45 NA
399.5→229.3
TTPC First Confirmatory 399.5→75.9 40 46 8.1 0.92
Second Confirmatory 40 10 3.02
399.5→343.5
TABLE 4 Concentrations of Calibration Standards (ng/L)
Concentrations
LV1 LV2 LV3 LV4 LV5 LV6 LV7 LV8
(ng/L)
TTPC 25 50 100 200 400 600 800 1000
3.3.5 LCS/LCSD, n—Laboratory Control Sample/Laboratory Control Sample Duplicate
3.3.6 MDL, n—Method Detection Limit
3.3.7 MeOH, n—Methanol
-3
3.3.8 mM, n—millimolar, 1 × 10 moles/L
3.3.9 MRM, n—Multiple Reaction Monitoring
3.3.10 MS/MSD, n—Matrix Spike/Matrix Spike Duplicate
3.3.11 NA, adj—Not Available
3.3.12 ND, n—non-detect
3.3.13 P&A, n—Precision and Accuracy
3.3.14 ppt, n—parts-per-trillion
3.3.15 QA, adj—Quality Assurance
3.3.16 QC, adj—Quality Control
3.3.17 RL, n—Reporting Limit
3.3.18 RLCS, n—Reporting Limit Check Sample
3.3.19 RSD, n—Relative Standard Deviation
D8024 − 23
3.3.20 RT, n—Retention Time
3.3.21 SDS, n—Safety Data Sheets
3.3.22 SRM, n—Single Reaction Monitoring
3.3.23 SS, n—Surrogate Standard
3.3.24 TC, n—Target Compound
3.3.25 TTPBr, n—(Tri-n-butyl)-n-tetradecylphosphonium bromide
3.3.26 TTPC, n—(Tri-n-butyl)-n-tetradecylphosphonium chloride
3.3.27 VOA, n—Volatile Organic Analysis
4. Summary of Test Method
4.1 The operating conditions presented in this test method have been successfully used in the determination of TTPC in water;
however, this test method is intended to be performance based and alternative operating conditions can be used to perform this
method provided data quality objectives are attained.
4.2 For TTPC analysis, samples are shipped to the lab on ice and analyzed within 14 days of collection. A sample (2.5 mL) is
transferred to a VOA vial, a TTPC spike solution is added to Laboratory Control and Matrix Spike samples before the addition
of acetone. An isotopically labeled TTPC surrogate would be added at this point. An isotopically labeled TTPBr-D29 surrogate
is now available and should be incorporated into this method by the user if requested by the customer. 7.5 mL of acetone is them
added and the solution is mixed by hand or vortex for 1 minute. 1 min. The samples are then filtered through a Nylon membrane
syringe driven filter unit and then analyzed by LC/MS/MS. All concentrations reported only to the reporting limit.
4.3 TTPC is identified by comparing the single reaction monitoring (SRM) transition and its confirmatory SRM transitions if
correlated to the known standard SRM transition (Table 3) and quantitated utilizing an external calibration. The final report issued
for each sample lists the concentration of TTPC, if detected, or RL, if not detected, in ng/L and surrogate recovery, if available.
5. Significance and Use
5.1 TTPC may be used in various industrial and commercial products for use as a biocide. Products containing TTPC have been
approved for controlling algal, bacterial, and fungal slimes in industrial water systems. TTPC should not be persistent in water
TABLE 5 Preparation of Calibration Standards
Solution LV1 LV2 LV3 LV4 LV5 LV6 LV7 LV8
A
A 25 μL 50 μL 100 μL 200 μL 400 μL 600 μL 800 μL 1000 μL
B
B 975 μL 950 μL 900 μL 800 μL 600 μL 400 μL 200 μL 0 μL
A
Solution A: Level 8 stock solution prepared according to Section 12 and at Table 4 concentrations.
B
Solution B: 75 % Acetone, 25 % Water.
A surrogate, TTPBr-D29, was custom synthesized by Cambridge Isotope Laboratories Inc., Andover, MA 01810 and was found to be acceptable. Any commercial source
of TTPBr-D29 surrogate may be used, SRM transition 428.6 > 372.5 was used. If you are aware of an alternative source 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 Whatman Puradisc (a trademark of Whatman International Limited of Maidstone, Kent) 25 NYL Disposable Filter unit (Diameter 25 mm, 0.2 μm Nylon membrane
syringe driven filter unit has been found suitable for use for this method, any filter unit may be used that meets the performance of this method may be used. If you are aware
of an alternative filter 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.
D8024 − 23
but may be deposited in sediments at concentrations of concern. Hence, there is a need for quick, easy and robust method to
determine TTPC concentration at trace levels in water matrices for understanding the sources and concentration levels in affected
areas.
5.2 This method has been used to determine TTPC in reagent water and a river water (Table 8).
NOTE 1—This test method has been used to characterize TTPC in real world water samples with success and similar recoveries as shown in Table 8.
6. Interferences
6.1 All glassware is washed in hot water with detergent and rinsed in hot water followed by distilled water. The glassware is then
dried and heated in an oven at 250°C for 15 to 30 minutes. 250 °C for 15 min to 30 min. All glassware is subsequently rinsed and/or
sonicated with acetone, n-propanol and/or acetonitrile.or sonicated, or both, with acetone, n-propanol, or acetonitrile, or
combinations thereof.
6.2 TTPC should not be a common contaminant found in a laboratory, unless involved in the analysis or matrices that contain
TTPC. TTPC has been found to continue to adhere to glassware and syringes after routine glassware washing. Rinsing glassware
with acetone, n-propanol and/orn-propanol, or acetonitrile, or combinations thereof, or even sonication, may be required to remove
TTPC. All of the materials and supplies are routinely demonstrated to be free from interferences of TTPC by analyzing laboratory
blanks under the same conditions as the samples. If found, measures should be taken to remove the contamination or data should
be qualified, background subtraction of blank contamination is not allowed.
6.3 All reagents and solvents should be pesticide residue purity or higher to minimize interference problems.
6.4 Matrix interferences may be caused by contaminants in the sample. The extent of matrix interferences can vary considerably
depending on variations in the sample matrices.
6.5 Automatic pipettes with polypropylene tips were used to prepare the standards, spiking, and calibration solutions. The use of
glass syringes for preparing standards, spiking, and calibration solutions generated erratic results; glass syringes should be avoided
for these critical tasks. A thoroughly cleaned 1010 mL or 20 mL hypodermic glass syringe with a nylon filter was found to perform
well to filter the 10 mL prepared sample. 20 mL 20 mL Luer-Lock polypropylene syringes have also been shown to meet the
performance of this test method; these are disposable and do not require cleaning before use. It seems when preparing small
volumes of solutions, concentrations are affected by adhesion of TTPC to the syringe barrel or plunger.
TABLE 6 QC Acceptance Criteria
NOTE 1—Table 6 data is preliminary until a multi-lab validation study is completed.
Initial Demonstration of Performance Laboratory Control Sample
Spike
Recovery (%) Precision Recovery (%)
Analyte Conc.
Maximum
Lower Control Limit Upper Control Limit
ng/L
Lower Limit Upper Limit
(LCL) % (UCL) %
% RSD
TTPC 2000 70 130 30 70 130
D8024 − 23
TABLE 7 MS/MSD QC Acceptance Criteria
NOTE 1—Table 7 data is preliminary until a multi-lab validation study is completed.
MS/MSD Precision
Spike
Analyte Conc. Recovery (%)
RPD (%)
ng/L
Lower Limit Upper Limit
TTPC 2000 70 130 30
TABLE 8 Single-Laboratory Recovery Data in Water
Reagent Water P&A Data CRW P&A Data
(2000 ng/L spike) (2000 ng/L spike)
Sample
TTPC TTPC
MB 1 MB 2 P&A 1 1861 1898
P&A 2 1891 1965
P&A 3 1882 1933
P&A 4 1894 1871
P&A 5 1975 1929
P&A 6 1975 1974
Average Recovery (ng/L) 1893 1928
% Average Recovery 94.6 96.4
Standard Deviation 42.8 39.1
RSD (%) 2.26 2.03
NOTE 2—The use of PTFE, PVDF and polypropylene filter units resulted in poor performance and low recoveries.
7. Apparatus
7.1 LC/MS/MS System:
7.1.1 Liquid Chromatography SystemSystem——A complete LC system is required 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 LC system that is capable of performing
at the flows, pressures, controlled temperatures, sample volumes, and requirements of this test method shallmust be used.
7.1.2 Analytical Column —A reverse phase C18 particle column was used to develop this test method. Any column that achieves
adequate resolution may be used. The retention times and order of elution may change depending on the column used and need
to be monitored.
7.2 Tandem Mass Spectrometer SystemSystem——A MS/MS system capable of multiple reaction monitoring (MRM) analysis or
any system that is capable of meeting the requirements in this test method shallmust be used.
7.3 Adjustable Volume Pipettes—10, 20, 100, and 1000 μL and 5 and 10 mL.10 μL, 20 μL, 100 μL, 1000 μL, 5 mL, and 10 mL.
NOTE 3—Any pipette may be used providing the data generated meets the performance of this test method.
7.3.1 Pipette Tips—Polypropylene pipette tips free of release agents or low retention coating of various sizes.
7.4 Class A Volumetric Glassware.
7.5 Filtration Device.
A Waters Acquity UPLC BEH C18, 2.12.1 mm × 100 mm and 1.7 μm particle size column, or equivalent, has been found suitable for use. It was used to develop this
test method and generate the precision and biascolumn 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, data presented in
Section which you may attend.16.
D8024 − 23
7.5.1 Hypodermic Syringe—A Luer-Lock tip glass or polypropylene syringe capable of holding a syringe driven filter unit.
7.5.2 A 1010 mL or 20 mL Lock Tip Syringe size is recommended since a 10 mL prepared sample size is used in this test method.
If a smaller volume syringe is used, do not wash out the syringe or change filters while filtering the same sample if multiple refills
of the syringe is required in order to filter the 10 mL 10 mL prepared sample.
7.5.3 Filter Unit —Nylon filter units were used to filter the samples.
7.6 Vials—2-mL autosampler vials (LC vials) with pre-slit PTFE/silicone septa or equivalent.
7.7 VOA Vials—40 mL.
7.8 Sonicator.
7.9 Oven, capable to achieve 250°C.250 °C.
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
Committee on Analytical Reagents of the American Chemical Society. Other reagent grades may be used provided they are first
determined to be of sufficiently high purity to permit their use without affecting the accuracy of the measurements.
8.2 Purity of Water—Unless otherwise indicated, references to water shallmust be understood to mean reagent water conforming
to Type 1 of Specification D1193. It shallmust be demonstrated that this water does not contain contaminants at concentrations
sufficient to interfere with the analysis.
8.3 All prepared solutions are routinely replaced every year if not previously discarded for quality control failure.
8.4 Gases—Ultrapure nitrogen and argon.
8.5 Acetone (CAS # 67-64-1).
8.6 Acetonitrile (CAS # 75-05-8).
8.7 Methanol (CAS # 67-56-1).
8.8 Ammonium Acetate (CAS # 631-61-8).
8.9 2-Propanol (isopropyl alcohol, CAS # 67-63-0).
8.10 Ottawa Sand (CAS # 14808-60-7).
8.11 (Tri-n-butyl)-n-tetradecylphosphonium chloride (CAS # 81741-28-8).
8.12 (Tri-n-butyl)-n-tetradecylphosphonium bromide –D29 (TTPBr-D29, CAS # NA, optional surrogate).
A Whatman Puradisc 25 NYL Disposable Filter unit (diameter 25 mm, 0.2 μm nylon membrane syringe driven filter unit) has been found suitable for use for this method.
Any filter unit may be used was used. If you are aware of an alternative filter that meets the performance of this method. 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.
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 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. Pharmacopeial Convention, Inc. (USPC),
Rockville, MD.
D8024 − 23
9. Hazards
9.1 Normal laboratory safety applies to this method. Analysts should wear safety glasses, gloves, and lab coats when working in
the lab. Analysts should review the Safety Data Sheets (SDS) for all reagents used in this method.
10. Sampling and Preservation
10.1 Grab samples are collected in glass containers with Tefloninert-lined-lined caps. As part of the overall quality assurance
program for this test method, field blanks exposed to the same field conditions as samples are collected and analyzed according
to this test method to assess the potential for field contamination, refer to Guide D3856 as a guide for sampling. This test method
is based on a 2.5 mL sample size per analysis. If different sample sizes are used, spiking solution amounts may need to be modified.
EPA Publication SW-8466 may be used as a sampling guide. Samples shallmust be shipped with a trip blank and at less than
6°C.between above freezing and 6 °C.
10.2 Once received the sample temperature is taken and should be less than 6°C.6 °C. If the receiving temperature is greater than
6°C,6 °C, the sample temperature is noted in the case narrative accompanying the data. Samples should be stored refrigerated
between 0°C and 6°Cabove freezing and 6 °C from the time of collection until analysis.
10.3 The sample should be analyzed within 14 days of collection. No holding time study has been done on water matrices tested
in this test method. Holding time may vary depending on the matrix and individual laboratories should determine the holding time
in their matrix, refer to Practice D4841.
11. Preparation of LC/MS/MS
11.1 LC Chromatograph Operating Conditions:
11.1.1 Injections of all standards and samples are made at a 50 μL volume. Other injection volumes may be used to optimize
conditions. Standards and sample extracts shallmust be in a 75:25 acetone:water solution. In the case of extreme concentration
differences amongst samples, it is wise to analyze a blank after a concentrated sample and before a dilute sample to minimize
carry-over of analytes from injection to injection. However, there should not be carry-over between samples. The LC utilized to
develop this test method has a flow through LC needle design. The gradient conditions for liquid chromatography are shown in
Table 2.
11.2 LC Sample Manager Conditions:
11.2.1 Needle Wash Solvent—60 %60 % acetonitrile acetonitrile/40 % ⁄40 % 2-propanol. Eight-second wash time before and after
injection. Instrument manufacturer’s specifications should be followed in order to eliminate sample carry-over.
11.2.2 Temperatures—Column, 35°C;35 °C; sample compartment, 15°C.15 °C.
11.2.3 Seal Wash—Solvent: 50 %50 % methanol methanol/5 0 % ⁄50 % water; time: 5 minutes.5 min.
11.3 Mass Spectrometer Parameters:
11.3.1 To acquire the maximum number of data points per SRM channel while maintaining adequate sensitivity, the tune
parameters may be optimized according to the instrument used. Each peak requires at least 10 scans per peak for adequate
quantitation. Variable parameters regarding SRM transitions, and cone and collision energies are shown in Table 3. The values for
the following parameters are shown here for information only. These conditions should be checked and optimized when required.
Mass spectrometer parameters used in the development of this method are listed below:
The instrument is set in the Electrospray positive source setting:
Capillary Voltage: 1 kV
Cone: Variable depending on analyte
Source Temperature: 150°C
Source Temperature: 150 °C
Desolvation Gas Temperature: 500°C
Desolvation Gas Temperature: 500 °C
Desolvation Gas Flow: 900 L/hr
D8024 − 23
Desolvation Gas Flow: 900 L/h
Cone Gas Flow: 150 L/hr
Cone Gas Flow: 150 L/h
Collision Gas Flow: 0.15 mL/min
Low Mass Resolution 1: 3
Low Mass Resolution 1:3
High Mass Resolution 1: 14
High Mass Resolution 1:14
Ion Energy 1: 1
Ion Energy 1:1
Entrance Ener
...