ASTM D7730-17

Standard Test Method for Determination of Dioctyl Sulfosuccinate in Sea Water by Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)

SIGNIFICANCE AND USE
5.1 DOSS is an anionic detergent that is approved by the United States Food and Drug Administration (U.S. FDA) and is used widely as a laxative, emulsifying, solubilizing, and dispersing agent, and is used in the cosmetic industry.4 DOSS may also be used as a dispersing agent to treat oil. DOSS may be released into the environment at levels that may be harmful to aquatic life. The U.S. EPA aquatic life benchmark for DOSS is 40 ppb.5  
5.2 This test method has been investigated for use with reagent and sea water.
SCOPE
1.1 This test method covers the determination of dioctyl sulfosuccinate (DOSS) in sea water by direct injection using liquid chromatography (LC) and detection with tandem mass spectrometry (MS/MS). This analyte is qualitatively and quantitatively determined by this test method. This test method adheres to selected reaction monitoring (SRM) mass spectrometry.  
1.2 The detection verification level (DVL) and reporting range for DOSS are listed in Table 1.  
1.2.1 The DVL is required to be at a concentration at least 3 times below the reporting limit (RL) and have a signal/noise ratio greater than 3:1. Fig. 1 and Fig. 2 display the signal/noise ratio of the selected reaction monitoring (SRM) transition.  
FIG. 1 Detection Verification Level Signal/Noise Ratio  
FIG. 2 Reporting Level Signal/Noise Ratio  
1.2.2 The reporting limit is the concentration of the Level 1 calibration standard as shown in Table 5 for DOSS, taking into account the 50 % sample preparation dilution factor.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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-Dec-2017
• ICS: 71.060.50 - Salts
• Technical Committee: D19 - Water
• Drafting Committee: D19.06 - Methods for Analysis for Organic Substances in Water

Relations

• Replaces: ASTM D7730-11 - Standard Test Method for Determination of Dioctyl Sulfosuccinate in Sea Water by Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)
• Effective Date: 15-Dec-2017
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• 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 D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• 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 D1129-04e1 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2004
• Refers: ASTM D1129-04 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2004
• Refers: ASTM D1129-03a - Standard Terminology Relating to Water
• Effective Date: 10-Aug-2003
• Refers: ASTM D2777-03 - Standard Practice for Determination of Precision and Bias of Applicable Methods of Committee D-19 on Water
• Effective Date: 10-Aug-2003
• Refers: ASTM D1129-03 - Standard Terminology Relating to Water
• Effective Date: 10-Mar-2003

Overview

ASTM D7730-17 is the internationally recognized standard test method developed by ASTM for the determination of dioctyl sulfosuccinate (DOSS) in sea water. This standard utilizes direct injection liquid chromatography with tandem mass spectrometry (LC/MS/MS) to detect and quantify DOSS residues. DOSS is a commonly used anionic detergent and surfactant, found in pharmaceuticals, cosmetics, and as an oil dispersant. Due to its widespread applications, monitoring DOSS in marine environments is vital for ensuring compliance with regulatory benchmarks and protecting aquatic life. The U.S. Environmental Protection Agency (EPA) sets a benchmark of 40 ppb for DOSS in aquatic systems, underscoring the importance of precise and reliable detection methods.

Key Topics

• Test Method Scope: The standard outlines procedures for both qualitative and quantitative determination of DOSS in sea water. It employs selective reaction monitoring (SRM) within LC/MS/MS, ensuring high specificity and sensitivity.
• Detection Capabilities: The detection verification level (DVL) for DOSS is set at 3 µg/L, with a reporting range from 20 to 400 µg/L. These parameters allow laboratories to accurately identify and report DOSS concentrations at levels relevant to regulatory thresholds.
• Sample Preparation: Detailed steps are provided for collecting, preserving, and preparing sea water samples, ensuring minimal contamination or analyte loss. Proper use of glassware and certified high-purity reagents is emphasized to avoid background interference.
• Quality Control: Strict quality assurance measures are included, such as method blanks, laboratory control samples, surrogates, and matrix spikes. These ensure the reliability, accuracy, and reproducibility of results.
• Data Calibration and Analysis: The method covers calibration procedures, including use of external standards and calculation of results using linear or quadratic regression.

Applications

ASTM D7730-17 is applicable across multiple sectors where environmental monitoring and safety are necessary:

• Environmental Monitoring: Used by marine research organizations and regulatory agencies to monitor DOSS contamination and assess compliance with environmental standards.
• Oil Spill Response: Essential for evaluating the residual presence of DOSS used as a dispersant following oil spill treatments, supporting environmental impact assessments.
• Industrial Discharge Control: Relevant for industries that either use or produce DOSS-containing products, ensuring that wastewater discharges do not exceed established limits.
• Pharmaceutical and Cosmetic Industry: Supports manufacturers in confirming that wastewater management practices prevent the release of hazardous surfactants into marine environments.

Related Standards

For comprehensive water quality monitoring and analysis, the following standards are commonly referenced alongside ASTM D7730-17:

• 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
• EPA SW-846 – Test Methods for Evaluating Solid Waste, Physical/Chemical Methods

Summary

Adopting ASTM D7730-17 enables laboratories and industries to accurately monitor DOSS concentrations in sea water using LC/MS/MS. This standard supports regulatory compliance, environmental stewardship, and public health by offering a validated, robust analytical procedure. Implementing this method ensures precise measurement of DOSS, guiding effective pollution prevention and control strategies in marine and estuarine environments.

By integrating ASTM D7730-17 into routine water quality monitoring protocols, organizations demonstrate commitment to global environmental standards and sustainable 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:D7730 −17
Standard Test Method for
Determination of Dioctyl Sulfosuccinate in Sea Water by
Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/
MS)
This standard is issued under the fixed designation D7730; 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 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers the determination of dioctyl
D1129Terminology Relating to Water
sulfosuccinate (DOSS) in sea water by direct injection using
D1193Specification for Reagent Water
liquid chromatography (LC) and detection with tandem mass
D2777Practice for Determination of Precision and Bias of
spectrometry (MS/MS).This analyte is qualitatively and quan-
Applicable Test Methods of Committee D19 on Water
titatively determined by this test method. This test method
2.2 Other Standards:
adherestoselectedreactionmonitoring(SRM)massspectrom-
EPAPublication SW-846Test Methods for Evaluating Solid
etry.
Waste, Physical/Chemical Methods
1.2 The detection verification level (DVL) and reporting
range for DOSS are listed in Table 1. 3. Terminology
1.2.1 The DVL is required to be at a concentration at least
3.1 Definitions:
3 times below the reporting limit (RL) and have a signal/noise
3.1.1 For definitions of terms used in this standard, refer to
ratiogreaterthan3:1.Fig.1andFig.2displaythesignal/noise
Terminology D1129.
ratio of the selected reaction monitoring (SRM) transition.
3.2 Definitions of Terms Specific to This Standard:
1.2.2 The reporting limit is the concentration of the Level 1
3.2.1 detection verification level, DVL, n—a concentration
calibrationstandardasshowninTable5forDOSS,takinginto
that has a signal/noise ratio greater than 3:1 and is at least 3
account the 50 % sample preparation dilution factor.
times below the reporting limit (RL).
3.2.2 reporting limit, RL, n—the concentration of the
1.3 The values stated in SI units are to be regarded as
lowest-level calibration standard used for quantification.
standard. No other units of measurement are included in this
standard.
3.3 Abbreviations:
–3
3.3.1 mM—millimolar,1×10 moles/L
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.3.2 NA—no addition
responsibility of the user of this standard to establish appro-
3.3.3 ND—non-detect
priate safety, health, and environmental practices and deter-
3.3.4 ppb—parts per billion, µg/L
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
4. Summary of Test Method
dance with internationally recognized principles on standard-
4.1 This is a performance-based method, and modifications
ization established in the Decision on Principles for the
are allowed to improve performance.
Development of International Standards, Guides and Recom-
4.2 For DOSS analysis, samples are shipped to the lab
mendations issued by the World Trade Organization Technical
between 0°C and 6°C and analyzed within 5 days. In the lab,
Barriers to Trade (TBT) Committee.
the entire collected 20-mL sample is spiked with surrogate,
1 2
This test method is under the jurisdiction ofASTM Committee D19 on Water For referenced ASTM standards, visit the ASTM website, www.astm.org, or
andisthedirectresponsibilityofSubcommitteeD19.06onMethodsforAnalysisfor contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Organic Substances in Water. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Dec. 15, 2017. Published January 2018. Originally the ASTM website.
approved in 2011. Last previous edition approved in 2011 as D7730 – 11. DOI: Available from NationalTechnical Information Service (NTIS), 5301 Shawnee
10.1520/D7730-17. Rd., Alexandria, VA 22312, http://www.ntis.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7730−17
TABLE 1 Detection Verification Level (DVL) and Reporting Range
6.5 Matrix interferences may be caused by contaminants in
DVL Reporting Range the sample. The extent of matrix interferences can vary
Analyte
(µg/L) (µg/L)
considerably from sample source depending on variations of
DOSS 3 20–400
the sample matrix.
6.6 Sulfonate filters contribute significantly to background
interference and should be avoided for this standard. In
ammoniumformatebuffersolutionandbroughttoavolumeof
additiontosamplefiltration,sulfonatefiltersmaybepresentin
40 mL with acetonitrile. This prepared sample is then filtered
water purification systems.
using a syringe driven filter unit, and analyzed by LC/MS/MS.
Ifvisibleoilispresent,thepreparedsampleisallowedtosettle
7. Apparatus
resulting in an oil layer at the top of the 40-mL solution. A
portionoftheaqueous(bottom)layerisfiltered,leavingtheoil
7.1 LC/MS/MS System:
layer behind, through a syringe driven filter assembly and
7.1.1 Liquid Chromatography System—Acomplete LC sys-
analyzed by LC/MS/MS.
tem is needed in order to analyze samples. Any system that is
capable of performing at the flows, pressures, controlled
4.3 DOSS and DOSS surrogate are quantitated by retention
temperatures, sample volumes, and requirements of the stan-
time and one SRM transition. The final report issued for each
dard may be used.
sample lists the concentration of DOSS and the surrogate
7.1.2 Analytical Column—WatersAtlantis dC18, 2.1 × 150
recovery.
mm, 3-µm particle size was used to develop this test method.
5. Significance and Use
Anycolumnthatachievesbaselineresolutionoftheseanalytes
may be used. Baseline resolution simplifies data analysis and
5.1 DOSS is an anionic detergent that is approved by the
can reduce the chance of ion suppression, leading to higher
United States Food and Drug Administration (U.S. FDA) and
limits of detection. The retention times and order of elution
is used widely as a laxative, emulsifying, solubilizing, and
may change depending on the column used and need to be
dispersing agent, and is used in the cosmetic industry. DOSS
monitored.
may also be used as a dispersing agent to treat oil. DOSS may
7.1.3 Tandem Mass Spectrometer System—A MS/MS sys-
be released into the environment at levels that may be harmful
tem capable of MRM analysis. Any system that is capable of
toaquaticlife.TheU.S.EPAaquaticlifebenchmarkforDOSS
performing at the requirements in this standard may be used.
is 40 ppb.
7.2 Filtration Device:
5.2 This test method has been investigated for use with
7.2.1 Hypodermic syringe—A Lock Tip Glass Syringe ca-
reagent and sea water.
pableofholdingaMillexHVSyringeDrivenFilterUnitPVDF
9,10
6. Interferences
0.22 µm, or similar, may be used.
7.2.1.1 A Lock Tip Glass Syringe was used in this test
6.1 Methodinterferencesmaybecausedbycontaminantsin
method.
solvents, reagents, glassware, and other apparatus producing
7.2.2 Filter—Millex HV Syringe Driven Filter Unit PVDF
discrete artifacts or elevated baselines. All of these materials
0.22 µm, or similar, may be used.
are demonstrated to be free from interferences by analyzing
laboratory reagent blanks under the same conditions as
8. Reagents and Materials
samples.
8.1 Purity of Reagents—High Performance Liquid Chroma-
6.2 All glassware is washed in hot water with detergent and
tography (HPLC) pesticide residue analysis and spectropho-
rinsed in hot water followed by distilled water. The glassware
tometry grade chemicals shall be used in all tests. Unless
is then dried and heated in an oven at 250°C for 15 to 30
indicated otherwise, it is intended that all reagents shall
minutes.All glassware is subsequently cleaned with methanol
conform to the Committee on Analytical Reagents of the
or 50 % acetonitrile/50 % water, or both.
6.3 Systemcontaminationandsurfacebindingareproblem-
atic as DOSS is a surface active compound. It is important to
A Waters ACQUITY UltraPerformance Liquid Chromatography (UPLC)
thoroughly rinse sample containers with organic solvent to
System, a trademark of the Waters Corporation, Milford, MA, was used to develop
thistestmethod.Allparametersinthistestmethodarebasedonthissystemandmay
accurately measure DOSSconcentrations.Thoroughrinsing of
vary depending on your instrument.
all lab equipment is necessary to reduce contamination. Care-
The Waters Atlantis dC18 is a trademark of the Waters Corporation, Milford,
fully analyze blanks to ensure that the method minimizes
MA.
DOSS carryover. A Waters Quattro Premier XE tandem quadrupole mass spectrometer, a
trademark of the Waters Corporation, Milford, MA, was used to develop this test
6.4 All reagents and solvents should be pesticide residue
method.All parameters in this test method are based on this system and may vary
purity or higher to minimize interference problems. depending on your instrument.
The sole source of supply of the Millex HV Syringe Driven Filter Unit PVDF
0.45 µm known to the committee at this time is Millipore Corporation, Catalog #
Code of Federal Regulations—Title 21: Food and Drugs, Part 172, Available SLHV033NS. If you are aware of alternative suppliers, please provide this
from U.S. Government Printing Office, Superintendent of Documents, 732 N. information to ASTM International Headquarters. Your comments will receive
Capitol St., NW, Washington, DC 20401-0001, http://www.access.gpo.gov. careful consideration at a meeting of the responsible technical committee, which
AdditionalinformationaboutDOSSisavailableathttp://www.epa.gov/bpspill/ you may attend.
dispersant-methods.html (2010) Millex is a trademark of Merck KGAA, Darmstadt, Germany.
D7730−17
FIG. 1Detection Verification Level Signal/Noise Ratio
FIG. 2Reporting Level Signal/Noise Ratio
D7730−17
American Chemical Society. Other reagent grades may be 10.2 DOSS is surface active. The surface activity results in
used provided they are first determined to be of sufficiently DOSS adhering to many materials. Sampling techniques that
highpuritytopermittheirusewithoutaffectingtheaccuracyof expose samples to materials other than the sample container
the measurements. may reduce DOSS concentration in samples. Sampling tech-
niques such as peristaltic pumping expose the sample to large
8.2 Purity of Water—Unless otherwise indicated, references
surface areas compared to sample volume. Grab sampling
towatershallbeunderstoodtomeanreagentwaterconforming
techniques should be used. Transferring of sample from an
toType1ofSpecificationD1193.Itmustbedemonstratedthat
initial collection device to sampling vial may result in biased
this water does not contain contaminants at concentrations
low DOSS concentrations and must be avoided.
sufficient to interfere with the analysis.
8.3 Gases—Ultrapure nitrogen and argon.
11. Preparation of LC/MS/MS
8.4 Acetonitrile (CH CN, CAS # 75-05-8).
3 6
11.1 LC Chromatograph Operating Conditions:
8.5 Methanol (CAS # 67-56-1).
11.1.1 Injection volumes of all calibration standards and
8.6 Ammonium formate (NH CO H, CAS # 540-69-2). samples are made at 50-µLvolume using a full loop injection.
4 2
“Full loop” mode is the preferred technique when performing
8.7 2-Propanol (CAS # 67-63-0).
quantitative analyses. Multiple blank samples should be ana-
8.8 Dioctylsulfosuccinate(DOSS)purchasedasthesodium
lyzed at the beginning of a run to remove residual DOSS from
salt (CAS # 577-11-7).
the system. The first sample analyzed after the calibration
8.9 Dioctyl sulfosuccinate- C , (bis(2-ethylhexyl) sulfos- curve is a blank to ensure there is negligible (less than the
uccinate (Fumaric acid- C ) sodium salt (Unlabeled CAS # DVL) DOSS carry-over.The gradient conditions for the liquid
577-11-7), (Optional Surrogate, custom synthesis). chromatograph are shown in Table 2. Divert the column flow
away from the electrospray source for 0 to 5 minutes after
8.10 Dioctyl sulfosuccinate-D (DOSS-D ), bis(2-
34 34
injection.Flowdiversiontowastemaybedoneusingthemass
ethylhexyl-D ) sulfosuccinate sodium salt (Unlabeled CAS #
spectrometer divert valve, divert tubing configurations vary
577-11-7).
from manual injection. Test the divert valve configuration and
operationpriortoanalysis.Seawatersamplescontainnonvola-
9. Hazards
tile salts; the elution from injection to 5 minutes after injection
9.1 Normal laboratory safety applies to this test method.
is diverted to waste in order to prevent mass spectrometer
Analysts should wear safety glasses, gloves, and lab coats
sourcecontamination.Ifthereiscarry-overfromonesampleto
when working in the lab.Analysts should review the Material
another, greater than half the reporting limit, the initial per-
Safety Data Sheets (MSDS) for all reagents used in this test
centage of acetonitrile should be raised as shown in Table 3 to
method.
try and remove the carry-over. This will shorten the elution
timeofDOSSapproximately1minute;thereforeitisnecessary
10. Sampling
reducetheflowdiversionandadjusttheMRMtime.Increasing
10.1 Sampling and Preservation—Grab samples should be
the initial acetonitrile gradient concentration does not increase
collected in 20-mL pre-cleaned glass vials with TFE-
the DVL or reporting limit.
fluorocarbon–lined septa caps demonstrated to be free of
11.2 LC Sample Manager Conditions:
interferences. This test method is based on a 20-mL sample
size per analysis. Each sample should be collected in duplicate
11.2.1 Wash Solvents—Weak wash is 4.0 mL of 50 %
andaquadruplicatesamplemustbeincludedwitheachsample
water/50 % acetonitrile. Strong wash is 2.0 mL of 60 %
batch of 10 for MS/MSD quality control analyses. Store
acetonitrile/40 % 2-propanol. The strong wash solvent is
samplesbetween0°Cand6°Cfromthetimeofcollectionuntil
needed to eliminate carry-over between injections of DOSS
analysis. Analyze the sample within five days of collection.
samples. The weak wash is used to remove the strong wash
solvent. Instrument manufacturer specifications should be fol-
lowed in order to eliminate sample carry-over.
Reagent Chemicals, American Chemical Society Specifications, American
11.2.2 Temperatures—Column, 35°C; sample compartment,
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
15°C.
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
11.2.3 Seal Wash—Solvent: 50 % acetonitrile/50 % water;
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
time: 2 minutes.
MD.
TABLE 2 Gradient Conditions for DOSS Liquid Chromatography
Time (min) Flow (mL/min) Percent 95 % Water/ 5 % CH CN, 5mMNH CO H Percent 95 % CH CN/ 5 % Water, 5 mM NH CO H
3 4 2 3 4 2
0.0 0.3 100 0
2.0 0.3 100 0
5.0 0.3 0 100
8.0 0.3 0 100
8.3 0.3 100 0
10.0 0.3 100 0
D7730−17
TABLE 3 Gradient Conditions for DOSS Liquid Chromatography Starting with a Higher Acetonitrile Concentration
Percent 95 % Water/ 5 % CH CN, 5 mM Percent 95 % CH CN/ 5 % Water, 5 mM
3 3
Time (min) Flow (mL/min)
NH CO H NH CO H
4 2 4 2
0.0 0.3 50 50
2.0 0.3 50 50
5.0 0.3 0 100
8.0 0.3 0 100
8.3 0.3 50 50
10.0 0.3 50 50
11.3 Mass Spectrometer Parameters: 12.1.1 AccountforthepurityandsodiummassoftheDOSS
11.3.1 To acquire the maximum number of data points per standards. The DOSS anion is quantitated, therefore the cali-
SRM channel while maintaining adequate sensitivity, the tune brations standards should be the DOSS anion concentration.
parameters may be optimized according to your instrument. For example:
Each peak requires at least 10 scans per peak for adequate 10.76 mg of 98 % pure dioctyl sulfosuccinate sodium salt
quantitation. This procedure will contain one surrogate, which standard contains 10.54 mg of dioctyl sulfosuccinate sodium
is isotopically labeled DOSS, DOSS-quantitation and DOSS- salt (577-11-7),
confirmation are in one MRM acquisition function to optimize 10.54 mg of dioctyl sulfosuccinate sodium salt (577-11-7)
sensitivity. Variable parameters regarding retention times, contains 10.00 mg of dioctyl sulfosuccinate (DOSS), and
SRM transitions, and cone and collision energies are shown in 10.00 mg of DOSS in 50.0 mL 50 % acetonitrile/50 %
Table 4. Mass spectrometer parameters used in the develop- water contains 200.0 ppm DOSS.
ment of this test method are listed below:
12.2 Calibration and Standardization—To calibrate the
The instrument is set in the Electrospray negative source setting.
instrument,analyzesevencalibrationstandards;thecalibration
Capillary Voltage: 3.5 kV
standards nominal concentrations are detailed in Table 5.A
Cone: Variable depending on analyte (Table 4)
calibration solution is prepared from standard materials or
Extractor: 2 Volts
RF Lens: 0.3 Volts
certified solutions. Level 7 calibration solution containing the
Source Temperature: 120°C
DOSS and surrogate is prepared and aliquots of that solution
Desolvation Temperature: 350°C
are diluted to prepare Levels 1 through 6 and the DVL. The
Desolvation Gas Flow: 800 L/hr
Cone Gas Flow: 25 L/hr
following steps will produce standards with the concentration
Low Mass Resolution 1: 14.0
values shown in Table 5. The analyst is responsible for
High Mass Resolution 1: 14.0
Ion Energy 1: 0.8 recording initial component weight, calculating dilutions and
Entrance Energy: -1
preparing appropriate solutions. The DOSS 421.1 > 80.6
Collision Energy: Variable depending on analyte (Table 4)
transition (Table 4) shall be used for DOSS quantitation. The
Exit Energy: 0
DOSS confirmatory transition (421.1>183.1) serves to support
Low Mass Resolution 2: 14.0
High Mass resolution 2: 14.0
DOSS identification, but is not required due to low sensitivity
Ion Energy 2: 1.0
and may not be seen at lower concentrations.
Multiplier: 650
-3
12.2.1 PrepareLevel7calibrationstockstandardat200ppb
Gas Cell Pirani Gauge: 7.0 × 10 Torr
Inter-Channel Delay: 0.02 seconds
by adding to a 10-mL volumetric flask individual solutions of
Inter-Scan Delay: 0.01 seconds
thefollowing:100µLofDOSSandDOSS-D eachat20ppm
Dwell: 0.1 seconds
Solvent Delay: 5 minutes in 50 % water/50 % acetonitrile and dilute to 10 mL with a
solution of 5 millimolar ammonium formate in 50 % water/50
12. Calibration and Standardization
% acetonitrile. The preparation of the stock standard can be
12.1 The mass spectrometer must be calibrated in accor- accomplished using different volumes and concentrations of
dance with manufacturer specifications before analysis. In stock solutions as is accustomed in the individual laboratory.
order to obtain accurate analytical values through using this Depending on the prepared stock concentrations, the solubility
test method within the confidence limits, the following proce- at that concentration will have to be ensured.
dures must be followed when performing this test method. 12.2.2 Aliquots of Level 7 calibration stock standard are
Prepare all solutions in the lab using Class A volumetric then diluted with 5 millimolar ammonium formate in 50 %
glassware. water/50%acetonitriletopreparethedesiredcalibrationlevels
TABLE 4 Retention Times, SRM transitions, and DOSS-Specific Mass Spectrometer Parameters
SRM Mass Transition (Parent >
Analyte Retention time (min) Cone Voltage (Volts) Collision Energy (eV)
Product)
DOSS 6.44 36 24 421.1 > 80.6
A
DOSS-confirmatory 6.44 36 15 421.1 > 183.1
DOSS-D (Surrogate) 6.16 37 26 455.3 > 80.6
DOSS- C (Optional 6.44 36 24 425.3 > 80.6
Surrogate)
A
DOSS-confirmatory SRM transition observed at higher DOSS concentrations, not required for DOSS identification.
D7730−17
TABLE 5 Concentrations of Calibration Standards (PPB)
Analyte/
DVL LV 1 LV 2 LV 3 LV 4 LV 5 LV 6 LV 7
Surrogate
DOSS 3 10 20 40 60 100 150 200
DOSS- 3 10 20 40 60 100 150 200
D (Surrogate)
in 2-mL amber glass autosampler vials. The calibration vials re-injected. If the retention time is still incorrect in the sample,
mustbeusedwithin24hourstoensureoptimumresults.Stock refer to the analyte as an unknown.
calibrationstandardsareroutinelyreplacedeverysevendaysif
12.2.7 A calibration check standard (near the midpoint, for
notpreviouslydiscardedforqualitycontrolfailure.Calibration
example: 60 or 100 ppb) must be analyzed at the end of each
standards are not filtered.
batch of 20 samples or within 24 hours after the initial
12.2.3 Injecteachstandardandobtainitschromatogram.An
calibration curve was generated. The end calibration check
external calibration technique is used to monitor the SRM
should be the same calibration standard that was used to
transitions of each analyte. Calibration software is utilized to
generate the initial curve. The regression result from the end
conduct the quantitation of the target analytes and surrogates
calibration check standard must have a percent deviation less
using the SRM transition. The calibration software manual
than 35 % from the target analyte and surrogate nominal
should be consulted to use the software correctly. The quanti-
concentration. If the results are not within these criteria, the
tation method is set as an external calibration using the peak
problem must be corrected and either all samples in the batch
areas in ppb units. Concentrations may be calculated using the
must be re-analyzed against a new calibration curve or the
data system software to generate linear regression or quadratic
affected results must be qualified with an indication that they
calibration curves. Forcing the calibration curve through the
are not within the performance criteria of this test method. If
origin is not recommended.
the analyst inspects the vial containing the end calibration
12.2.4 Linear calibration may be used if the coefficient of
check standards and notices that the samples evaporated
determination, r , is >0.98 for the analyte. The point of origin
affecting the concentration, a new end calibration check
is excluded and a fit weighting of 1/X is used in order to give
standardmaybemadeandanalyzed.Ifthisnewendcalibration
more emphasis to the lower concentrations. If one of the
checkstandardhasapercentdeviationlessthan35%fromthe
calibration standards other than the high or low point causes
calculated concentration for the target analyte and surrogate,
ther ofthecurvetobe<0.98,thispointmustbere-injectedor
the results may be reported unqualified.
a new calibration curve must be regenerated. If the Level 1 or
12.3 If a laborato
...

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: D7730 − 11 D7730 − 17
Standard Test Method for
Determination of Dioctyl Sulfosuccinate in Sea Water by
Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/
MS)
This standard is issued under the fixed designation D7730; 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 dioctyl sulfosuccinate (DOSS) in sea water by direct injection using
liquid chromatography (LC) and detection with tandem mass spectrometry (MS/MS). This analyte is qualitatively and
quantitatively determined by this test method. This test method adheres to selected reaction monitoring (SRM) mass spectrometry.
1.2 The Detection Verification Leveldetection verification level (DVL) and Reporting Rangereporting range for DOSS are listed
in Table 1.
1.2.1 The DVL is required to be at a concentration at least 3 times below the Reporting Limitreporting limit (RL) and have a
signal/noise ratio greater than 3:1. Fig. 1 and Fig. 2 display the signal/noise ratio of the selected reaction monitoring (SRM)
transition.
1.2.2 The reporting limit is the concentration of the Level 1 calibration standard as shown in Table 5 for DOSS, taking into
account the 50% 50 % sample preparation dilution factor.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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 safety, health, and healthenvironmental 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
2.2 Other Standards:
EPA publication SW-846,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:Definitions of Terms Specific to This Standard:
3.2.1 detection verification level, DVL, n—a concentration that has a signal/noise ratio greater than 3:1 and is at least 3 times
below the Reporting Limitreporting limit (RL).
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 May 1, 2011Dec. 15, 2017. Published July 2011January 2018. Originally approved in 2011. Last previous edition approved in 2011 as D7730
– 11. DOI: 10.1520/D7730–11.10.1520/D7730-17.
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 National Technical Information Service (NTIS), U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA, 22161 or at http://www.epa.gov/
epawaste/hazard/testmethods/index.htm5301 Shawnee Rd., Alexandria, VA 22312, http://www.ntis.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7730 − 17
TABLE 1 Detection Verification Level and Reporting Range
DVL Reporting Range
Analyte
(μg/L) (μg/L)
DOSS 3 20-400
TABLE 1 Detection Verification Level (DVL) and Reporting Range
DVL Reporting Range
Analyte
(μg/L) (μg/L)
DOSS 3 20–400
3.2.2 reporting limit, RL, n—the concentration of the lowest-level calibration standard used for quantification.
3.2 Abbreviations:
3.2.1 ppb—parts per billion, μg/L
-3
3.2.2 mM—millimolar, 1 x 10 moles/L
3.2.3 NA—no addition
3.2.4 ND—non-detect
3.3 Abbreviations:
–3
3.3.1 mM—millimolar, 1 × 10 moles/L
3.3.2 NA—no addition
3.3.3 ND—non-detect
3.3.4 ppb—parts per billion, μg/L
4. Summary of Test Method
4.1 This is a performance based performance-based method, and modifications are allowed to improve performance.
4.2 For DOSS analysis, samples are shipped to the lab between 0°C and 6°C and analyzed within 5 days. In the lab, the entire
collected 20 mL 20-mL sample is spiked with surrogate, ammonium formate buffer solution and brought to a volume of 40 mL
with acetonitrile. This prepared sample is then filtered using a syringe driven filter unit, and analyzed by LC/MS/MS. If visible
oil is present, the prepared sample is allowed to settle resulting in an oil layer at the top of the 40 mL 40-mL solution. A portion
of the aqueous (bottom) layer is filtered, leaving the oil layer behind, through a syringe driven filter assembly and analyzed by
LC/MS/MS.
4.3 DOSS and DOSS surrogate are quantitated by retention time and one SRM transition. The final report issued for each
sample lists the concentration of DOSS and the surrogate recovery.
5. Significance and Use
5.1 DOSS is an anionic detergent that is approved by the United States Food and Drug Administration (U.S. FDA) and is used
widely as a laxative, emulsifying, solubilizing, and dispersing agent, and is used in the cosmetic industry. DOSS may also be used
as a dispersing agent to treat oil. DOSS may be released into the environment at levels that may be harmful to aquatic life. The
USU.S. EPA aquatic life benchmark for DOSS is 40 ppb.
5.2 This test method has been investigated for use with reagent and sea water.
6. Interferences
6.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other apparatus producing
discrete artifacts or elevated baselines. All of these materials are demonstrated to be free from interferences by analyzing laboratory
reagent blanks under the same conditions as samples.
6.2 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. All glassware is subsequently cleaned with methanol or 50%
acetonitrile/50% 50 % acetonitrile/50 % water, or both.
6.3 System contamination and surface binding are problematic as DOSS is a surface active compound. It is important to
thoroughly rinse sample containers with organic solvent to accurately measure DOSS concentrations. Thorough rinsing of all lab
equipment is necessary to reduce contamination. Carefully analyze blanks to ensure that the method minimizes DOSS carryover.
6.4 All reagents and solvents should be pesticide residue purity or higher to minimize interference problems.
Code of Federal Regulations-TitleRegulations—Title 21: Food and Drugs, Part 172 available at http://www.gpoaccess.gov/cfr/index.html.172, Available from U.S.
Government Printing Office, Superintendent of Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://www.access.gpo.gov.
Additional information about DOSS is available at http://www.epa.gov/bpspill/dispersant-methods.html (2010)
D7730 − 17
FIG. 1 Detection Verification Level Signal/Noise Ratio.Ratio
FIG. 2 Reporting Level Signal/Noise Ratio.Ratio
6.5 Matrix interferences may be caused by contaminants in the sample. The extent of matrix interferences can vary considerably
from sample source depending on variations of the sample matrix.
6.6 Sulfonate filters contribute significantly to background interference and should be avoided for this standard. In addition to
sample filtration, sulfonate filters may be present in water purification systems.
7. Apparatus
7.1 LC/MS/MS SystemLC/MS/MS System:
D7730 − 17
7.1.1 Liquid Chromatography System—A complete LC system is needed in order to analyze samples. Any system that is
capable of performing at the flows, pressures, controlled temperatures, sample volumes, and requirements of the standard may be
used.
7.1.2 Analytical Column—Waters—Column—Atlantis™ Waters Atlantis dC18, 2.1 x× 150 mm, 3 μm 3-μm particle size was
used to develop this test method. Any column that achieves baseline resolution of these analytes may be used. Baseline resolution
simplifies data analysis and can reduce the chance of ion suppression, leading to higher limits of detection. The retention times
and order of elution may change depending on the column used and need to be monitored.
7.1.3 Tandem Mass Spectrometer System—A MS/MS system capable of MRM analysis. Any system that is capable of
performing at the requirements in this standard may be used.
7.2 Filtration DeviceDevice:
7.2.1 Hypodermic syringe—A Lock Tip Glass Syringe capable of holding a Millex®Millex HV Syringe Driven Filter Unit
9,10
PVDF 0.22 μm, or similar, may be used.
7.2.1.1 A Lock Tip Glass Syringe was used in this test method.
7.2.2 Filter—Millex®Millex HV Syringe Driven Filter Unit PVDF 0.22 μm (Millipore Corporation, Catalog # SLGV033NS)
or similarμm, or similar, may be used.
8. Reagents and Materials
8.1 Purity of Reagents—High Performance Liquid Chromatography (HPLC) pesticide residue analysis and spectrophotometry
grade chemicals shall be used in all tests. Unless indicated otherwise, it is intended that all reagents shall 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 shall be understood to mean reagent water conforming to
Type 1 of Specification D1193. It must be demonstrated that this water does not contain contaminants at concentrations sufficient
to interfere with the analysis.
8.3 Gases—Ultrapure nitrogen and argon.
8.4 Acetonitrile (CH CN, CAS # 75-05-8).
8.5 Methanol (CAS # 67-56-1).
8.6 Ammonium formate (NH CO H, CAS # 540-69-2).
4 2
8.7 2-Propanol (CAS # 67-63-0).
8.8 Dioctyl sulfosuccinate (DOSS) purchased as the sodium salt (CAS # 577-11-7).
13 13
8.9 Dioctyl sulfosuccinate- C , (bis(2-ethylhexyl) sulfosuccinate (Fumaric acid- C ) sodium salt (Unlabeled CAS #
4 4
577-11-7), (Optional Surrogate, custom synthesis).
8.10 Dioctyl sulfosuccinate-D (DOSS-D ), bis(2-ethylhexyl-D ) sulfosuccinate sodium salt (Unlabeled CAS # 577-11-7).
34 34 17
9. Hazards
9.1 Normal laboratory safety applies to this test method. Analysts should wear safety glasses, gloves, and lab coats when
working in the lab. Analysts should review the Material Safety Data Sheets (MSDS) for all reagents used in this test method.
10. Sampling
10.1 Sampling and Preservation—Grab samples should be collected in 20 mL 20-mL pre-cleaned glass vials with Teflon® lined
TFE-fluorocarbon–lined septa caps demonstrated to be free of interferences. This test method is based on a 20 mL 20-mL sample
size per analysis. Each sample should be collected in duplicate and a quadruplicate sample must be included with each sample
batch of 10 for MS/MSD quality control analyses. Store samples between 0°C and 6°C from the time of collection until analysis.
Analyze the sample within 5five days of collection.
A Waters ACQUITY UltraPerformance Liquid Chromatography (UPLC®) System (UPLC) System, a trademark of the Waters Corporation, Milford, MA, was used to
develop this test method. All parameters in this test method are based on this system and may vary depending on your instrument.
The Waters Atlantis dC18 is a trademark of the Waters Corporation, Milford, MA.
A Waters Quattro Premier™Premier XE tandem quadrupole mass spectrometer spectrometer, a trademark of the Waters Corporation, Milford, MA, was used to develop
this test method. All parameters in this test method are based on this system and may vary depending on your instrument.
The sole source of supply of the Millex HV Syringe Driven Filter Unit PVDF 0.45 μm known to the committee at this time is Millipore Corporation, Catalog #
SLHV033NS. 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.
Millex is a trademark of Merck KGAA, Darmstadt, Germany.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, D.C.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 Formulators,Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
D7730 − 17
10.2 DOSS is surface active. The surface activity results in DOSS adhering to many materials. Sampling techniques that expose
samples to materials other than the sample container may reduce DOSS concentration in samples. Sampling techniques such as
peristaltic pumping expose the sample to large surface areas compared to sample volume. Grab sampling techniques should be
used. Transferring of sample from an initial collection device to sampling vial may result in biased low DOSS concentrations and
must be avoided.
11. Preparation of LC/MS/MS
6 6
11.1 LC Chromatograph Operating Conditions LC Chromatograph Operating Conditions:
11.1.1 Injection volumes of all calibration standards and samples are made at 50 μL 50-μL volume using a full loop injection.
“Full loop” mode is the preferred technique when performing quantitative analyses. Multiple blank samples should be analyzed
at the beginning of a run to remove residual DOSS from the system. The first sample analyzed after the calibration curve is a blank
to ensure there is negligible (Less(less than the DVL) DOSS carry-over. The gradient conditions for the liquid chromatograph are
shown in Table 2. Divert the column flow away from the electrospray source for 0 to 5 minutes after injection. Flow diversion to
waste may be done using the mass spectrometer divert valve, divert tubing configurations vary from manual injection. Test the
divert valve configuration and operation prior to analysis. Seawater samples contain nonvolatile salts; the elution from injection
to 5 minutes after injection is diverted to waste in order to prevent mass spectrometer source contamination. If there is carry-over
from one sample to another, greater than half the reporting limit, the initial percentage of acetonitrile should be raised as shown
in Table 3 to try and remove the carry-over. This will shorten the elution time of DOSS approximately 1 minute; therefore it is
necessary reduce the flow diversion and adjust the MRM time. Increasing the initial acetonitrile gradient concentration does not
increase the DVL or reporting limit.
11.2 LC Sample Manager Conditions : Conditions:
11.2.1 Wash Solvents—Weak wash is 4.0 mL of 50% water/50% 50 % water/50 % acetonitrile. Strong wash is 2.0 mL of 60%
acetonitrile/40% 60 % acetonitrile/40 % 2-propanol. The strong wash solvent is needed to eliminate carry-over between injections
of DOSS samples. The weak wash is used to remove the strong wash solvent. Instrument manufacturer specifications should be
followed in order to eliminate sample carry-over.
11.2.2 Temperatures—Column, 35°C; Samplesample compartment, 15°C.
11.2.3 Seal Wash—Solvent: 50% acetonitrile/50% water; Time:50 % acetonitrile/50 % water; time: 2 minutes.
TABLE 2 Gradient Conditions for DOSS Liquid Chromatography
Percent 95% Water/ 5% 95 % Water/ 5 % CH CN, 5 Percent 95% 95 % CH CN/ 5% 5 % Water, 5 mM
3 3
Time (min) Flow (mL/min)
mM NH CO H NH CO H
4 2 4 2
0.0 0.3 100 0
2.0 0.3 100 0
5.0 0.3 0 100
8.0 0.3 0 100
8.3 0.3 100 0
10.0 0.3 100 0
D7730 − 17
TABLE 3 Gradient Conditions for DOSS Liquid Chromatography Starting with a Higher Acetonitrile Concentration
Percent 95% Water/ 5% 95 % Water/ 5 % Percent 95% 95 % CH CN/ 5% 5 % Water, 5 mM
Time (min) Flow (mL/min)
CH CN, 5 mM NH CO H NH CO H
3 4 2 4 2
0.0 0.3 50 50
2.0 0.3 50 50
5.0 0.3 0 100
8.0 0.3 0 100
8.3 0.3 50 50
10.0 0.3 50 50
11.3 Mass Spectrometer ParametersParameters: :
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 your instrument. Each peak requires at least 10 scans per peak for adequate quantitation.
This procedure will contain one surrogate, which is isotopically labeled DOSS, DOSS-quantitation and DOSS-confirmation are in
one MRM acquisition function to optimize sensitivity. Variable parameters regarding retention times, SRM transitions, and cone
and collision energies are shown in Table 4. Mass spectrometer parameters used in the development of this test method are listed
below:
The instrument is set in the Electrospray negative source setting.
Capillary Voltage: 3.5 kV
Cone: Variable depending on analyte (Table 4)
Extractor: 2 Volts
RF Lens: 0.3 Volts
Source Temperature: 120°C
Desolvation Temperature: 350°C
Desolvation Gas Flow: 800 L/hr
Cone Gas Flow: 25 L/hr
Low Mass Resolution 1: 14.0
High Mass Resolution 1: 14.0
Ion Energy 1: 0.8
Entrance Energy: -1
Collision Energy: Variable depending on analyte (Table 4)
Exit Energy: 0
Low Mass Resolution 2: 14.0
High Mass resolution 2: 14.0
Ion Energy 2: 1.0
Multiplier: 650
-3
Gas Cell Pirani Gauge: 7.0 x 10 Torr
Inter-Channel Delay: 0.02 seconds
Inter-Scan Delay: 0.01 seconds
Dwell: 0.1 seconds
Solvent Delay: 5 minutes
The instrument is set in the Electrospray negative source setting.
Capillary Voltage: 3.5 kV
Cone: Variable depending on analyte (Table 4)
Extractor: 2 Volts
RF Lens: 0.3 Volts
Source Temperature: 120°C
Desolvation Temperature: 350°C
Desolvation Gas Flow: 800 L/hr
TABLE 4 Retention Times, SRM transitions, and DOSS-Specific Mass Spectrometer Parameters
SRM Mass Transition (Parent >
Analyte Retention time (min) Cone Voltage (Volts) Collision Energy (eV)
Product)
DOSS 6.44 36 24 421.1 > 80.6
A
DOSS-confirmatory 6.44 36 15 421.1>183.1
A
DOSS-confirmatory 6.44 36 15 421.1 > 183.1
DOSS-D (Surrogate) 6.16 37 26 455.3 > 80.6
DOSS- C (Optional 6.44 36 24 425.3> 80.6
Surrogate)
DOSS- C (Optional 6.44 36 24 425.3 > 80.6
Surrogate)
A
DOSS-confirmatory SRM transition observed at higher DOSS concentrations, not required for DOSS identification.
D7730 − 17
Cone Gas Flow: 25 L/hr
Low Mass Resolution 1: 14.0
High Mass Resolution 1: 14.0
Ion Energy 1: 0.8
Entrance Energy: -1
Collision Energy: Variable depending on analyte (Table 4)
Exit Energy: 0
Low Mass Resolution 2: 14.0
High Mass resolution 2: 14.0
Ion Energy 2: 1.0
Multiplier: 650
-3
Gas Cell Pirani Gauge: 7.0 × 10 Torr
Inter-Channel Delay: 0.02 seconds
Inter-Scan Delay: 0.01 seconds
Dwell: 0.1 seconds
Solvent Delay: 5 minutes
12. Calibration and Standardization
12.1 The mass spectrometer must be calibrated per in accordance with manufacturer specifications before analysis. In order to
obtain accurate analytical values through using this test method within the confidence limits, the following procedures must be
followed when performing thethis test method. Prepare all solutions in the lab using Class A volumetric glassware.
12.1.1 Account for the purity and sodium mass of the DOSS standards. The DOSS anion is quantitated, therefore the
calibrations standards should be the DOSS anion concentration. For example:
10.76 mg of 98% pure dioctyl sulfosuccinate sodium salt standard contains 10.54 mg of dioctyl sulfosuccinate sodium salt
(577-11-7),
10.76 mg of 98 % pure dioctyl sulfosuccinate sodium salt standard contains 10.54 mg of dioctyl sulfosuccinate sodium salt
(577-11-7),
10.54 mg of dioctyl sulfosuccinate sodium salt (577-11-7) contains 10.00 mg of dioctyl sulfosuccinate (DOSS), and
10.00 mg of DOSS in 50.0 mL 50 % acetonitrile/50 % water contains 200.0 ppm DOSS.
10.54 mg of dioctyl sulfosuccinate sodium salt (577-11-7) contains 10.00 mg of dioctyl sulfosuccinate (DOSS),
10.00 mg of DOSS in 50.0 mL 50 % acetonitrile/50% water contains 200.0 ppm DOSS.
12.2 Calibration and Standardization—Calibration and Standardization– To calibrate the instrument, analyze seven calibration
standards; the calibration standards nominal concentrations are detailed in Table 5. A calibration solution is prepared from standard
materials or certified solutions. Level 7 calibration solution containing the DOSS and surrogate is prepared and aliquots of that
solution are diluted to prepare Levels 1 through 6 and the DVL. The following steps will produce standards with the concentration
values shown in Table 5. The analyst is responsible for recording initial component weight, calculating dilutions and preparing
appropriate solutions. The DOSS 421.1 > 80.6 transition (Table 4) shall be used for DOSS quantitation. The DOSS confirmatory
transition (421.1>183.1) serves to support DOSS identification, but is not required due to low sensitivity and may not be seen at
lower concentrations.
12.2.1 Prepare Level 7 calibration stock standard at 200 ppb by adding to a 10 mL 10-mL volumetric flask individual solutions
of the following: 100 μL of DOSS and DOSS-D each at 20 ppm in 50% water/50% 50 % water/50 % acetonitrile and dilute to
10 mL with a solution of 5 millimolar ammonium formate in 50% water/50% 50 % water/50 % acetonitrile. The preparation of
the stock standard can be accomplished using different volumes and concentrations of stock solutions as is accustomed in the
individual laboratory. Depending on the prepared stock concentrations, the solubility at that concentration will have to be ensured.
12.2.2 Aliquots of Level 7 calibration stock standard are then diluted with 5 millimolar ammonium formate in 50% water/50%
50 % water/50 % acetonitrile to prepare the desired calibration levels in 2 mL 2-mL amber glass autosampler vials. The calibration
vials must be used within 24 hours to ensure optimum results. Stock calibration standards are routinely replaced every 7seven days
if not previously discarded for quality control failure. Calibration standards are not filtered.
12.2.3 Inject each standard and obtain its chromatogram. An external calibration technique is used to monitor the SRM
transitions of each analyte. Calibration software is utilized to conduct the quantitation of the target analytes and surrogates using
the SRM transition. The calibration software manual should be consulted to use the software correctly. The quantitation method
is set as an external calibration using the peak areas in ppb units. Concentrations may be calculated using the data system software
to generate linear regression or quadratic calibration curves. Forcing the calibration curve through the origin is not recommended.
12.2.4 Linear calibration may be used if the coefficient of determination, r , is >0.98 for the analyte. The point of origin is
excluded and a fit weighting of 1/X is used in order to give more emphasis to the lower concentrations. If one of the calibration
TABLE 5 Concentrations of Calibration Standards (PPB)
Analyte/
DVL LV 1 LV 2 LV 3 LV 4 LV 5 LV 6 LV 7
Surrogate
DOSS 3 10 20 40 60 100 150 200
DOSS- 3 10 20 40 60 100 150 200
D (Surrogate)
D7730 − 17
standards other than the high or low point causes the r of the curve to be <0.98, this point must be re-injected or a new calibration
curve must be regenerated. If the Level 1 or Level 7 calibration result is excluded, minimally a five point five-point curve is
acceptable but the reporting range must be modified to reflect this change.
12.2.5 Quadratic calibration may be used if the coefficient of determination, r , is >0.99 for the analyte. The point of origin is
excluded, and a fit weighting of 1/X is used in order to give more emphasis to the lower concentrations. If one of the calibration
standards causes the curve to be <0.99, this point must be re-injected or a new calibration curve must be regenerated. At least six
calibration points are required for quadratic regression. If the Level 1 or Level 7 calibration result is excluded, the reporting range
must be modified to reflect this change. Each calibration point used to generate the curve must have a calculated percent deviation
less than 25% 25 % between the nominal concentration and the regression cal
...