Modern Water: 70620: PAH in water by immunoassay
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Official Method Name
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EnviroGard PAH in Water Test Kit 70620 (SDI 1998) http://www.sdix.com/ |
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Current Revision
| 1998 |
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Media
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WATER |
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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 concentration of analyte in the sample or standard. Calibrated for phenanthrene. Sensitivity to phenanthrene less than to anthracene, fluoranthene, chrysene, pyrene, and benzo(a)pyrene. Reagents are purchased in kits with manufacturers' instructions for sample preparation and analysis. Requirements: a supply of clean water and methanol, to dilute sample extracts, and to prepare standards; filtration equipment to remove particulates from water samples; a spectrometer, which accepts sample tubes (SDI EnviroGard), for analyses at visible wavelengths (450 nm primary; 600 or 650 nm reference); equipment to automate sample preparation for large numbers of samples (prefiltration, measurement of uL volumes, agitation), so that contact times with reagents are controlled as required; computerized data acquisition and processing. Expendable supplies - approximately $20 per determination. |
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Scope and Application
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Screening for ambient and compliance monitoring. Can be adapted 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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1 - 100 ug/L as phenanthrene |
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Interferences
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PAH tests (sensitivity to possible interferences, compared to phenanthrene): Sensitivity > phenanthrene: benzo(a)pyrene, fluoranthene, chrysene, pyrene, anthracene. Sensitivity < phenanthrene: indeno(1,2,3-cd)pyrene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, fluorene. Sensitivity << phenanthrene: dibenzo(a,h)anthracene, benzo(ghi)perylene, naphthalene, acenaphthalene, acenaphthylene |
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Quality Control Requirements
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Recommended for a kit allowing 20 qualitative determinations: a. calibration with 2 standards and 1 blank b. precision: 1 sample analyzed in duplicate (repeat) c. accuracy: 1 matrix sample, spiked with the target analyte at mid-range. d. validation: analysis of 1 positive and 1 negative sample 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. Immediate dilution with stabilizer (methanol:sample, 1:3, v/v) is recommended to inhibit adsorption to the container. Samples are held in a refrigerator at 4 oC. Immunoassay reagents and kits are stored in the dark at 4 to 8 oC until use. Water samples generally need to be centrifuged or prefiltered to 0.2 um. Aliquots of samples and reagents are accurately measured (uL) 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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