Modern Water: 7061301: PAH in soils/sediment by immunoassay
|
Official Method Name
|
PAH EnSys 12T Soil Test System 7061301 (SDI 1998) http://www.sdix.com/ |
|---|---|
|
Current Revision
| 1998 |
|
Media
|
SOILS/SEDIMENT |
|
Instrumentation
|
Immunoassay |
|
Method Subcategory
|
Organic |
|
Method Source
|
|
|
Citation
|
|
|
Brief Method Summary
|
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 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 analytical balance, to accurately determine weights of soil and sediment samples after drying and extraction; 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, rinsing, agitation), so that contact times with reagents are controlled as required; computerized data acquisition and processing. Expendable supplies - approximately $52 per determination. |
|
Scope and Application
|
Screening presence/absence for ambient and compliance monitoring. Can be used for Method 4035. Soil screening for polynuclear aromatic hydrocarbons by immunoassay (EPA 1995) |
|
Applicable Concentration Range
|
1, 10 ug/g as phenanthrene |
|
Interferences
|
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 |
|
Quality Control Requirements
|
Recommended for a kit allowing 12 qualitative determinations: a. calibration with 2 standards (1, 10 ug/g) and 1 blank (methanol) b. precision: 1 sample analyzed in duplicate (repeat) c. accuracy: 1 matrix sample, spiked at mid-range with the target analyte. d. validation: analysis of 1 positive sample by independent method for confirmation |
|
Sample Handling
|
Samples are typically collected in glass containers with Teflon-lined caps. Instructions are written for analysis in the field at the time of sampling. Immunoassay reagents and kits are stored in the dark at 4 to 8 oC until use. Soil and sediment samples need to be dried, weighed, and extracted (methanol; clean water). Soil extracts may need to be centrifuged or prefiltered to 0.2 um. Aliquots of sample extracts and reagents are accurately measured (uL) and mixed for required times, following manufacturer's instructions for use of the materials purchased. |
|
Maximum Holding Time
|
Instructions are written for analysis in the field at the time of sampling. |
|
Relative Cost
|
Less than $50 |
|
Sample Preparation Methods
|
