Document M4p6GXVp3VQomjdkJ9LvMzb5L

3M Environmental Laboratory R126-0005 M ethod A nalysis of Potassium Perfluorooctanesulfonate or O ther Fluorochemicals in Serum Extracts U sing H PLC-Electrospray/M ass Spectrometry Method Number: ETS-8-5.1 Author: Lisa Clemen, Robert Wynne Approved By: 'L l Laboratory Manager Adoption Date: 03/01/99 Revision Date: <V / 2 C / Date Group Leader Technical Reviewer Date dh i / m Date 1.0 S c o p e a n d A p p l ic a t io n __________________________________________________________________ 1.1 Scope: This method describes the analysis of serum extracts for fluorochemical surfactants using HPLC-electrospray/mass spectrometry. 1.2 Applicable Compounds: Fluorochemical surfactants or other fluorinated compounds, or other ionizable compounds. 1.3 Matrices: Rabbit, rat, bovine, monkey, and human serum, or other fluids as designated in the validation report. Word 6/95 ETS-8-5.1 Analysis o f Serum Extract Using ES/MS Page 1 of 9 001012 2.0 Summary of Method 2.1 This method describes the analysis of fluorochemical surfactants extracted from serum or other fluids, using HPLC-electrospray/mass spectrometry, or similar system as appropriate. The analysis is performed by monitoring a single ion characteristic of a particular fluorochemical, such as the perfluorooctanesulfonate (PFOS) anion, m/z^ 499. Additionally, samples may be analyzed using a tandem mass spectrometer to further verify the identity of a compound by detecting daughter ions of the parent ion. 3.0 D e f in it io n s _________________________________________________________________________________ 3.1 Atmospheric Pressure Ionization (API): The Micromass Quattro II triple quadrupole systems allow for various methods of ionization by utilizing various sources, probes, and interfaces. These include but are not limited to: Electrospray Ionization (ESI), Atmospheric Pressure chemical Ionization (APcI), Thermospray, etc. The ionization process in these techniques occurs at atmospheric pressure (i.e., not under a vacuum). 3.2 Electrospray Ionization (ES, ESI): a method of ionization performed at atmospheric pressure, whereby ions in solution are transferred to the gas phase via tiny charged droplets. These charged droplets are produced by the application of a strong electrical field. 3.3 Mass Spectrometry, Mass Spectrometer (MS), Tandem Mass Spectrometer (MS/MS): The API Quattro II triple quadrupole systems are equipped with quadrupole mass selective detectors. Ions are selectively discriminated by mass to charge ratio (m/z) and subsequently detected. A single MS may be employed for ion detection or a series (MS/MS) for more specific fragmentation information. 3.4 Conventional vs. Z-spray probe interface: The latest models of Micromass Quattro II triple quadrupole systems (post 1998) utilize a "Z-spray" conformation. The spray emitted from a probe is orthogonal to the cone aperture. In the conventional conformation it is aimed directly at the cone aperture, after passing through a tortuous pathway in the counter electrode. Though the configuration is different, the methods of operation, cleaning, and maintenance are the same. However, Z-spray components and conventional components are not compatible with one another, but only with similar systems (i.e., Z-spray components are compatible with some other Z-spray systems, etc.) 3.5 Mass Lynx Software: System software designed for the specific operation of these Quattro II triple quadrupole systems. Currently MassLynx has Windows 95 and WindowsNT 4.0 versions. All versions are similar. For more details see the manual specific to the instrument (Micromass Quattro II triple quadrupole MassLynx or MassLynx NT User's Guide). 4.0 W a r n in g s a n d C a u t io n s ________________________________________________________________ 4.1 Health and Safety Warnings: 4.1.1 Use caution with the voltage cables for the probe. When engaged, the probe employs a voltage of approximately 5000 Volts. 4.1.2 When handling samples or solvents wear appropriate protective gloves, eyewear, and clothing. ETS-8-5.1 Analysis o f Serum Extract Using ES/MS Page 2 o f 9 001013 4.2 Cautions: 4.2.1 Do not operate solvent pumps above capacity of 400 bar (5800 psi) back pressure. If the back pressure exceeds 400 bar, the HP1100 will initiate automatic shutdown. 4.2.2 Do not run solvent pumps to dryness. 5.0 I n t e r f e r e n c e s ___________________________________________________________________________ _ 5.1 To minimize interferences when analyzing samples, teflon should not be used for sample storage or any part of instrumentation that comes in contact with the sample or extract. 6.0 E q u ip m e n t ________________________________________________________________________________ _ 6.1 Equipment listed below may be modified in order to optimize the system. Document any modifications in the raw data as method deviations. 6.1.1 6.1.2 Micromass Quattro II triple quadrupole Mass Spectrometer equipped with an electrospray ionization source HP1100 low pulse solvent pumping system, solvent degasser, column compartment, and autosampler 7.0 S u p p l ie s a n d M a t e r ia l s ___________________________________________________________________ 7.1 Supplies 7.1.1 High purity grade nitrogen gas regulated to approximately 100 psi (House air system) 7.1.2 HPLC analytical column, specifics to be determined by the analyst and documented in the raw data. 7.1.3 Capped autovials or capped 15 mL centrifuge tubes 8.0 R e a g e n t s a n d S t a n d a r d s _________________________________________ ________________________ 8.1 Reagents 8.1.1 Methanol, HPLC grade or equivalent 8.1.2 Milli-QTM water, all water used in this method should be Milli-QTM water or equivalent, and may be provided by a Milli-Q TOC Plus system or other vendor 8.1.3 Ammonium acetate, reagent grade or equivalent 8.2 Standards 8.2.1 Typically two method blanks, two matrix blanks, and eighteen matrix standards are prepared during the extraction procedure. See ETS-8-4.1. 9.0 S a m p l e H a n d l in g __________________________________________________________________________ 9.1 Fresh matrix standards are prepared with each analysis. Extracted standards and samples are stored in capped autovials or capped 15 mL centrifuge tubes until analysis. ETS-8-5.1 Analysis o f Serum Extract Using ES/MS Page 3 of 9 001014 9.2 If analysis will be delayed, extracted standards and samples can be refrigerated at approximately 4 C, or at room temperature, until analysis can be performed. 10.0 Q u a l it y C o n t r o l _______________________________________________________________ _ 10.1 Solvent Blanks, Method Blanks and Matrix Blanks 10.1.1 Solvent blanks, method blanks and matrix blanks are prepared and analyzed with each batch to determine contamination or carryover. 10.1.2 Analyze a method blank and a matrix blank prior to each calibration curve. 10.2 Matrix Spikes 10.2.1 Matrix spikes are prepared and analyzed to determine the matrix effect on the recovery efficiency. 10.2.2 Matrix spike duplicates are prepared and analyzed to measure the precision and the recovery for each analyte. 10.2.3 Analyze a matrix spike and matrix spike duplicate per forty samples, with a minimum of 2 spikes per batch. 10.2.4 Matrix spike and matrix spike duplicate concentrations will fall in the mid-range of the initial calibration curve. Additional spike concentrations may fall in the lowrange of the initial calibration curve. 10.3 Continuing Calibration Verifications 10.3.1 Continuing calibration verifications are analyzed to verify the continued accuracy of the calibration curve. 10.3.2 Analyze a mid-range calibration standard after every tenth sample, with a minimum of one per batch. 11.0 C a l ib r a t io n a n d S t a n d a r d iz a t io n _____________________________________________________ 11.1 Analyze the extracted matrix standards prior to and following each set of extracts. The average of two standard curves will be plotted by linear regression (y = my + b), weighted 1/x, not forced through zero, using MassLynx or other suitable software. 11.2 If the curve does not meet requirements, perform routine maintenance or reextract the standard curve (if necessary) and reanalyze. 11.3 For purposes of accuracy when quantitating low levels of analyte, it may be necessary to use the low end of the calibration curve rather than the full range of the standard curve. Example: when attempting to quantitate approximately 10 ppb of analyte, generate a calibration curve consisting of the standards from 5 ppb to 100 ppb rather than the full range of the curve (5 ppb to 1000 ppb). This will reduce inaccuracy attributed to linear regression weighting of high concentration standards. ETS-8-5.1 Analysis o f Serum Extract Using ES/MS Page 4 of 9 001015 12.0 Procedures 12.1 Acquisition Set up 12.1.1 Click on start button in the Acquisition Control Panel. Set up a sample list. Assign a filename using MO-DAY-last digit of year-sample number, assign a method (MS) for acquiring, and type in sample descriptions. 12.1.2 To create a method click on scan button in the Acquisition control panel and select SIR (Single Ion Recording) or MRM. Set Ionization Mode as appropriate and mass to 499 or other appropriate masses. A full scan is usually collected along with the SIRs. Save acquisition method. If MS/MS instruments are employed, additional product ion fragmentation information may be collected. See Micromass MassLynx GUIDE TO DATA ACQUISITION for additional information and MRM (Multiple Reaction Monitoring). 12.1.3 Typically the analytical batch run sequence begins with a set of extracted matrix standards and ends with a set of extracted matrix standards. 12.1.4 Samples are analyzed with a continuing calibration check injected after every tenth sample. Solvent blanks should be analyzed periodically to monitor possible analyte carryover and are not considered samples but may be included as such. 12.2 Using the Autosampler 12.2.1 Set up sample tray according to the sample list prepared in Section 12.1.1, 12.2.2 Set-up the HP1100/autosampler at the following conditions or at conditions the analyst considers appropriate for optimal response. Record actual conditions in the instrument logbook: 12.2.2.1 Sample size = 10 p.L injection 12.2.2.2 Inject/sample = 1 12.2.2.3 Cycle time =13.5 minutes 12.2.2.4 Solvent ramp = Time 0.00 min. 8.50 min. 11.0 min. 12.0 min. MeOH 40% 90% 90% 40% 2.0 mM Ammonium acetate 60% 10% 10% 60% 12.2.2.5 Press the "Start" button. 12.3 Instrument Set-up 12.3.1 Refer to ETS-9-24.0 for more details. 12.3.2 Check the solvent level in reservoirs and refill if necessary. ETS-8-5.1 Analysis o f Serum Extract Using ES/MS Page 5 of 9 001016 12.3.3 Check the stainless steel capillary at the end of the probe. Use an eyepiece to check the tip. The tip should be flat with no jagged edges. If the tip is found to be unsatisfactory, disassemble the probe and replace the stainless steel capillary. 12.3.4 Set HPLC pump to "On". Set the flow to 10 - 500 uL/min or as appropriate. Observe droplets coming out of the tip of the probe. Allow to equilibrate for approximately 10 minutes. 12.3.5 Turn on the nitrogen. A fine mist should be expelled with no nitrogen leaking around the tip of the probe. Readjust the tip of the probe if no mist is observed. 12.3.6 The instrument uses these parameters at the following settings. These settings may change in order to optimize the response: 12.3.6.1 Drying gas 250-400 liters/hour 12.3.6.2 ESI nebulizing gas 10-15 liters/hour 12.3.6.3 HPLC constant flow mode, flow rate 10 - 500 pL/min 12.3.6.4 Pressure <400 bar (This parameter is not set, it is a guide to ensure the HPLC is operating correctly.) 12.3.7 Carefully guide the probe into the opening. Insert probe until it will not go any further. Connect the voltage cables to the probe. 12.3.8 Print the tune page, with its parameters, and store it in the study binder with a copy taped into the instrument log. 12.3.9 Using the cross-flow counter electrode in the ES/MS source is recommended for the analysis of biological matrices. 12.3.10Click on start button in the Acquisition Control Panel (this may vary among MassLynx versions, see appropriate MassLynx USER'S GUIDE). Press the start button. Ensure start and end sample number includes all samples to be analyzed. 13.0 D a t a A n a l y s is a n d C a l c u l a t io n s _______________________________________________________ 13.1 Calculations: 13.1.4 Calculate matrix spike percent recoveries using the following equation: % Recovery = Observed Result - Background Result x 100 Expected Result 13.1.5 Calculate percent difference using the following equation: % Difference = Expected Cone. - Calculated Cone, x 100 Expected Cone. 13.1.6 Calculate actual concentration of PFOS, or other fluorochemical, in matrix (pg/mL): (ng of PFOS calc, from std. Curve x Dilution Factor! x 1 ug /Initial Volume of matrix (mLl + mL of Surrogate Standard! 1000 ng Final Volume (mL) ETS-8-5.1 Analysis o f Serum Extract Using ES/MS Page 6 of 9 001017 14.0 Method Performance 14.1 Method Detection Limit (MDL) and Limit of Quantitation (LOQ) are method, analyte, and matrix specific. Please see ETS-8-4.1, Attachment B, for a listing of current validated MDL and LOQ values. 14.2 Solvent Blanks, Method Blanks, and Matrix Blanks 14.2.1 Solvent blanks, method blanks, and matrix blanks values are must be below the lowest standard in the calibration curve 14.3 Calibration Curves 14.3.1 The r2value for the calibration curve must be 0.980 or better. 14.4 Matrix Spikes 14.4.1 Matrix spike percent recoveries are must be within 30% of the spiked concentration. 14.5 Continuing Calibration Verifications 14.5.1 Continuing calibration verification percent recoveries must be 30% of the spiked concentration. 14.6 If criteria listed in this method performance section isn't met, maintenance may be performed on the system and samples reanalyzed or other actions as determined by the analyst. Document all actions in the appropriate logbook. 14.7 If data are to be reported when performance criteria have not been met, the data must be footnoted on tables and discussed in the text of the report. 15.0 P o l l u t io n P r e v e n t io n a n d W a s t e M a n a g e m e n t ______________________________________ 15.1 Sample extract waste and flammable solvent is disposed in high BTU containers, and glass pipette waste is disposed in broken glass containers located in the laboratory. 16.0 R e c o r d s ____________________________________________________________________________________ 16.1 Each page generated for a study must have the following information included either in the header or hand written on the page: study or project number, acquisition method, integration method, sample name, extraction date, dilution factor (if applicable), and analyst. 16.2 Print the tune page, sample list, and acquisition method from MassLynx to include in the appropriate study folder. Copy these pages and tape into the instrument runlog. 16.3 Plot the calibration curve by linear regression, weighted 1/x, then print these graphs and store in the study folder. 16.4 Print data integration summary, integration method, and chromatograms, from MassLynx, and store in the study folder. ETS-8-5.1 Analysis o f Serum Extract Using ES/MS Page 7 o f 9 001018 16.5 Summarize data using suitable software (Excel 5.0) and store in the study folder, see Attachment A for an example of a summary spreadsheet. 16.6 Back up electronic data to appropriate medium. Record in study notebook the file name and location of backup electronic data. 17.0 T a b l e s . D ia g r a m s . F l o w c h a r t s , a n d V a l id a t io n D a t a ______________________________ 17.1 Attachment A: ETS-8-5.1 Data summary spreadsheet. 18.0 R e f e r e n c e s ________________________________________________________________________________ 18.1 FACT-M-4.1, "Extraction of Potassium Perfluorooctanesulfonate or Other Fluorochemical compounds from Serum for Analysis Using HPLC-Electrospray/Mass Spectrometry 18.2 ETS-9-24.0, "Operation and Maintenance of the Micromass Atmospheric Pressure Ionization/Mass Spectrometer Quattro II triple quadrupole Systems" 18.3 The validation report associated with this method is ETS-8-4.0 & 5.0-V-l. 19.0 A f f e c t e d D o c u m e n t s ____________________________________________________________________ 19.1 ETS-8-4.1, "Extraction of Potassium Perfluorooctanesulfonate or Other Fluorochemical Compounds from Serum for Analysis Using HPLC-Electrospray/Mass Spectrometry" 20.0 R e v is io n s __________________________________________________________________________________ Revision Number. 1 Reason For Revision Section 6.1.2 Clarification of HP 1100 system components. Section 11.1 Average of two curves, not standard values, are used for plotting linear regression and added the 1/x weighting of the curve. Section 12.2.2.4 Clarification of solvent ramp. Section 17.1 Changed from attachment B to A. Revision Date 04/02/99 ETS-8-5.1 Analysis o f Serum Extract Using ES/MS Page 8 o f 9 001019 Laboratory Study # Study: Test Material: Matrix/Final Solvent: Method/Revision: Analytical Equipment System Number: Instrument Software/Version: Filename: R-Squared Value: Slope: Y Intercept: Date of Extraction/Analyst: Date o f Analysis/Analyst: Group Dose Sample# Concentration ug/mL Initial Vol. mL Dilution Factor Final Cone. ug/mL Slope: Taken from linear regression equation. Group/Dose: Taken from the study folder. Sample#: Taken from the study folder. Concentration (ug/mL): Taken from the MassLynx integration summary. Initial Volume (mL): Taken from the study folder. Dilution Factor: Taken from the study folder. Final Cone. (ug/mL): Calculated by dividing the initial volume from the concentration Attachment A: Summary Spreadsheet ETS-8-5.1 Analysis o f Serum Extract Using ES/MS Page 9 o f 9 001020