Final Decision to Certify Hazardous Waste Environmental Technology
EnviroGard™ Immunoassay for PCB's in Soil
Certification No: 94-01-005
The technology is an enzyme immunoassay for fast, semiquantitative field measurements of polychlorinated biphenyls (PCBs, as Aroclors) in soil. The antibody is supplied in a form bound to polystyrene test tubes. The reaction is performed on an extract prepared by dispersing and shaking a 5-gram sample of soil in a small volume of methanol. A color reaction shows whether the sample extract is equal to, above, or below a chosen target level. The assay is distributed in several formats; the methanol extraction kit is supplied separately. The target level in one format is 1 ppm, in another it can be selected as 5, 10, or 50 ppm (all concentrations based on Aroclor 1242). At these target levels, the confidence interval for negative samples exceeds 95%.
The assay responds similarly to Aroclors 1242 through 1260. It does not respond well to Aroclors 1221 and 1232. The quantification of unknown and weathered Aroclor mixtures requires comparison of results with those obtained by a laboratory method. Both high moisture content and significant oil contamination of soils interfere with the method. The nature of the reagents requires the user to avoid temperature extremes during transport and use. although the method has been tested for a number of possible interferences; results should be confirmed by an approved laboratory method (U.S. EPA SW- 846 Methods 8080 or 8081). The assay itself is accepted by U.S. EPA for use in Draft Method 4020 (Publication SW-846).
Recommended use of this type of assay is in preliminary site investigations where compelling historical data indicate the use of PCBs. In site investigations, the assays allow users to improve the mapping of PCB-polluted areas by a judicious combination of assay results with laboratory results. In remedial actions, progress can be estimated through on-the-spot testing.
Details of the DTSC's evaluation are contained and in an Evaluation Report.
A copy of the published Certification Notice may be obtained by contacting us at:
File last updated: October 9, 1996