Techniques and Methods 5–B2
Quality assurance reviews during May 2007 at USGS NWQL detected an error by which the identifications of Acetyl-hexamethyl-tetrahydronaphthalene (AHTN) and Hexahydrohexamethylcyclopentabenzopyran (HHCB) were reversed. This error affected data published in this report. The results in this revised publication reflect correct data reporting for these two compounds.
For more information on this issue see the National Water Quality Laboratory Technical Memorandum 2007.03 at http://nwql.usgs.gov/Public/tech_memos/nwql.07-03.htmlAbstract
A method for the determination of 61 compounds in environmental sediment and soil samples is described. The method was developed in response to increasing concern over the effects of endocrine-disrupting chemicals in wastewater and wastewater-impacted sediment on aquatic organisms. This method also may be used to evaluate the effects of combined sanitary and storm-sewer overflow on the water and sediment quality of urban streams. Method development focused on the determination of compounds that were chosen on the basis of their endocrine-disrupting potential or toxicity. These compounds include the alkylphenol ethoxylate nonionic surfactants and their degradates, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclic aromatic hydrocarbons, and high-use domestic pesticides.
Sediment and soil samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from interfering matrix components by high-pressure water/isopropyl alcohol extraction. The compounds were isolated using disposable solid-phase extraction (SPE) cartridges containing chemically modified polystyrene-divinylbenzene resin. The cartridges were dried with nitrogen gas, and then sorbed compounds were eluted with methylene chloride (80 percent)-diethyl ether (20 percent) through Florisil/sodium sulfate SPE cartridge, and then determined by capillary-column gas chromatography/mass spectrometry.
Recoveries in reagent-sand samples fortified at 4 to 72 micrograms averaged 76 percent ±13 percent relative standard deviation for all method compounds. Initial method reporting levels for single-component compounds ranged from 50 to 500 micrograms per kilogram. The concentrations of 20 out of 61 compounds initially will be reported as estimated with the “E” remark code for one of three reasons: (1) unacceptably low-biased recovery (less than 60 percent) or highly variable method performance (greater than 25 percent relative standard deviation), (2) reference standards prepared from technical mixtures, or (3) potential blank contamination.
Samples were preserved by freezing to –20 degrees Celsius. The U.S. Geological Survey National Water Quality Laboratory has established a 1-year sample-holding time limit (prior to sample extraction) from the date of sample collection (if the sample is kept at –20°C) until a statistically accepted method can be used to determine the effectiveness of the sample-freezing procedure.
Posted October 2007
Burkhardt, M.R., Zaugg, S.D., Smith, S.G., and ReVello, R.C., 2006, Determination of wastewater compounds in sediment and soil by pressurized solvent extraction, solid-phase extraction, and capillary-column gas chromatography/mass spectrometry: U.S. Geological Survey Techniques and Methods, book 5, chap. B2, 40 p.
Purpose and Scope
1. Scope and Application
2. Method Summary
3. Safety Precautions and Waste Disposal
5. Apparatus and Instrumentation
6. Reagents and Consumable Materials
8. Sample Preparation
9. Sample Analysis Procedure
10. Instrument Calibration
11. Quality Assurance and Quality Control
12. Calculation of Results
Results and Discussion of Method Validation
Summary and Conclusions
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