Document ZBV4YwKjm0LGbV5VGrX8oqRo8
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BIODEGRADATION
TEST SUBSTANCE
Identity: Remarks:
Perfluorooctanesulfonamide; may also be referred to as FOSA or F-10105 (1-Octanesulfonamide, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8heptadecafluoro, CAS # not available)
FOSA was a light yellow waxy solid. The 3M production lot number was not noted, the 3M standard identification # SD-029. Available GC information indicates the purity to be 95.1%. All results in this study were calculated assuming 100% purity.
METHOD:
Method:
Based on EPA Guidelines OPPTS 835.3200
Test Type: Aerobic
GLP:
No
Year Completed: 2001
Contact time: 18 days
Inoculum: Activated sludge collected 7/31/00 from the aeration basin at the Metro
Wastewater Treatment Plant, St Paul, MN. The MLSS was determined to be 2,280 mg/L
when first collected. The MLSS was stored at 4 C for approximately 5 weeks prior to
being used for this study. The sludge was allowed to settle and the solids used for
inoculum. The settled sludge constituted approximately 20% of the volume (~200 mL) of
the MLSS used.
Test medium: Test flasks were prepared using a mineral salts medium defined in EPA
Guideline OPPTS 835.3200. Methanol (1 mL per liter) was added per liter of mineral
medium. Fifty mL of settled sludge was added per liter of mineral salts medium. Mineral
medium plus sludge was prepared 9/7/00, while fresh mineral medium without sludge
(abiotic controls) was prepared 8/10/00.
Study design:
Blank Sludge Controls (mineral medium, inoculum)
Abiotic Controls
(mineral medium, FOSA)
Test Substance
(mineral medium, inoculum, FOSA)
Test vessels were set in duplicate. Additional quality control samples (blanks) were prepared and analyzed as appropriate.
Test concentration: 2.566 mg/L FOSA Incubation conditions:
Temperature: 25oC +/- 3oC Agitation: ~200 rpm Test vessels: Sterile 125 mL Nalgene polycarbonate culture flasks containing 25 mL of media
Dosing procedure: Test vessels were spiked with 6 pL of an 10,690 mg/L solution of FOSA in methanol yielding 2.566 mg/L. Sampling Frequency: Days 0 and 18. Analytical method: The day zero test vessels were prepared and immediately placed in a freezer that was maintained at -20oC until analyzed. After 18 days, the test vessels were removed from the incubator and frozen until final sample preparation by solid phase extraction (SPE). Following thawing, test vessel contents were adjusted to 1% acetic acid
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and then passed through a conditioned SEP-VAC C18 6cc SPE cartridge. Methanol was then added to the emptied culture flask, shaken vigorously and then passed through the SPE cartridge to extract adsorbed analytes. A second methanol wash was collected separately for analysis to ensure quantitative extraction.
Quantitative analysis was conducted on an HP1100 high performance liquid chromatograph with mass spectrometer detector (HPLC/MSD) system. The MSD was operated in electrospray ionization in negative-ion mode using selected-ion monitoring (SIM) for quantitation.
In addition to FOSA, the compounds below were quantified. In the case of the compounds that are potassium or ammonia salts, only the concentration of the fluorochemical anion was quantified and reported.
Compound Name Acronym
Chemical Formula
2-(N-Ethyl Perfluorooctane sulfonamido) ethyl alcohol N-EtFOSE Alcohol
C8FiySO2N(C2Ha)CH2CH2OH
2-(N-Ethyl Perfluorooctane sulfonamido) acetic acid N-EtFOSAA
C8F17SO2N(C2H5)(CH2COOH)
2-(Perfluorooctane sulfonamido) acetic acid M556
CbF!7 SO2NH(CH2COOH)
N-Ethyl Perfluorooctane sulfonamide N-EtFOSA
CbF!7 SO2NH(C2H5)
Perfluorooctane sulfinate, potassium salt PFOSulfinate C8F17SO2" K+
Perfluorooctanoate, ammonium salt PFOA
C7F!5COO_NH4+
Perfluorooctane sulfonate potassium salt PFOS
C8F17SO3" K+
Reference substance: None. When results from an EtFOSE Alcohol study conducted at the same time are compared to the previous EtFOSE Alcohol 35-day study, the viability of the microbial inoculum is confirmed.
RESULTS__________________________________________________
After 18 days, the analytical results1demonstrate that when exposed to municipal wastewater treatment sludge, 2.566 mg/L FOSA was poorly degraded. In this study
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89.8% of the starting concentration was remaining. The metabolites detected were PFOSulfinate, PFOS and PFOA. Mass balance for FOSA test vessels was excellent and ranged from 94 - 101%. No degradation of FOSA was observed in the abiotic controls.
CONCLUSIONS______________________________
Loss of only 10.2% of 2.825 mg/L of FOSA was demonstrated. The metabolites identified were PFOSulfinate, PFOS and PFOA. The results from this study indicated slower biotransformation of FOSA than expected when compared to the results from the previous 35-day study of N-EtFOSE alcohol.
DATA QUALITY
Klimisch ranking = 2. The study was conducted as a non-GLP study but with the understanding that good data quality objectives be met.
Determination of analyte recovery from spiked sample matrices was not deemed necessary as they have been determined twice previously at several different concentrations, and in both instances recoveries were near 100% with some exceptions for M556. Methanol and sample (mineral medium) blanks contained no detected target analytes.
Analyses of the blank sludge controls (mineral media plus inoculum) at days 0 and 18 demonstrated that the inoculum source did not contain endogenous concentrations of test substance or its metabolites.
A calculation error was discovered subsequent to issuance of the final report. The results and conclusions of the report are not affected. The PFOS molar conversion calculation should have used 538 ng/nmole rather than 522 ng/nmole. The corrected value for PFOS on page 13 of the report should be 92.9 nM.
REFERENCES
biodegradation Study Report, "The 18-Day Aerobic Biodegradation Study of Perfluoroctanesulfonyl-BasedChemistries", Contract Analytical Project ID: CA097, February 23, 2001. Conducted at the request of the 3M Company by Pace Analytical Services, Inc., Minneapolis, MN.
OTHER__________________________________________________
Submitter: 3M Company, Environmental Laboratory, P.O. Box 33331, St. Paul, Minnesota, 55133
Last changed: 6/21/01