Modern Water: A00201/A00204: PAH in soils/sediment by immunoassay
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Official Method Name
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Carcinogenic PAHs RaPID Assay A00201, with PAH Soil Extraction Kit A00204 (SDI 1998) http://www.sdix.com/ |
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Current Revision
| 1998 |
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Media
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SOILS/SEDIMENT |
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Instrumentation
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Immunoassay |
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Method Subcategory
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Organic |
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Method Source
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Citation
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Brief Method Summary
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Inhibition immunoassay, with a colorimetric indicator for competitive binding of analyte and an enzyme-labeled conjugate to surface-immobilized antibodies. Colorimetric response is inversely related to the (log) concentration of analyte in the sample or standard. Calibrated for benzo(a)pyrene. Sensitivity to benzo(a)pyrene less than to benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene, and chrysene. Reagents are purchased in kits with manufacturers' instructions for sample preparation and analysis. Requirements: a supply of clean water and methanol, to extract soil and sediment samples, to dilute sample extracts, and to prepare standards; filtration equipment to remove particulates from water samples and soil extracts; an oven and an analytical balance, to dry soil and sediments after extraction, and accurately determine sample weights; an SDI magnetic bead separator, required for the SDI RaPID assay kit; a spectrometer, which accepts sample tubes (SDI), for analyses at visible wavelengths (450 nm); equipment to automate sample preparation for large numbers of samples (prefiltration, measurement of uL volumes, rinsing, agitation), so that contact times with reagents are controlled as required; computerized data acquisition and processing. Expendable supplies - approximately $8 per determination |
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Scope and Application
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Ambient and compliance monitoring. Can be used for analysis of soils by Method 4035. Soil screening for polynuclear aromatic hydrocarbons by immunoassay (EPA 1995). |
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Applicable Concentration Range
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0.04 - 5 ug/g as benzo(a)pyrene |
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Interferences
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Carcinogenic PAH tests (sensitivity to possible interferences, compared to benzo(a)pyrene): Sensitivity > benzo(a)pyrene: benzo(a)anthracene, benzo(k)fluoranthene, benzo(b)fluoranthene, indeno(1,2,3-cd)pyrene, chrysene. Sensitivity < benzo(a)pyrene: dibenzo(a,h)anthracene, benzo(ghi)perylene, anthracene. Sensitivity << benzo(a)pyrene: phenanthrene, fluoranthene, pyrene, fluorene, naphthalene, acenaphthalene, acenaphthylene |
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Quality Control Requirements
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Recommended for a kit allowing 100 quantitative determinations: a. calibration with 3 standards and 1 blank, all analyzed in duplicate b. precision: all 46 samples analyzed in duplicate (repeats) c. accuracy: 3 matrix samples, spiked with the target analyte at different levels in the range for quantitative analysis. d. validation: analysis of 4 positive and 4 negative samples by an independent method, for confirmation |
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Sample Handling
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Samples are typically collected in glass containers with Teflon-lined caps. Samples are held in a refrigerator at 4 oC. Immunoassay reagents and kits are stored in the dark at 2 to 8 oC until use. Soil and sediment samples need to be extracted (clean water; methanol). Soil extracts generally need to be centrifuged or prefiltered to 0.2 um and diluted to 3 levels, in series. Aliquots of samples and reagents are accurately measured (mL) and mixed for required times, following manufacturer's instructions for use of the materials purchased. |
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Maximum Holding Time
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5 days at 4oC until extraction and analysis |
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Relative Cost
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Less than $50 |
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Sample Preparation Methods
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