The PENTA RISc Test System is designed to quickly provide semiquantitative results for pentachlorophenol (PCP) in soil and water samples. The system is shown in the photograph below.
PENTA RISc Test System
The technology uses immunoassay chemistry to produce compound-specific reactions that detect and quantify PCP. Polyclonal antibodies are fixed to the inside wall of a test tube, where they offer binding sites for PCP. An enzyme conjugate containing a PCP derivative is added to the test tube to compete with sample PCP for antibody binding sites. Excess sample and enzyme conjugate are washed from the test tube. Reagents are then added to the test tube to react with the enzyme conjugate, forming a color. After a designated time period, a solution is added to the test tube to stop color formation. The sample color is compared to the color formed by a PCP standard. A differential photometer compares the colors. The results obtained from soil samples are compared against a standard to determine the detection levels.
The system can be affected by extremes of naturally occurring matrix effects such as humic acids, pH, or salinity. Site-specific matrix effects that can affect the system include PCP carriers such as petroleum hydrocarbons or solvents; and other chemicals used in conjunction with PCP, including creosote, copper-chromium-arsenate, or herbicides. Specific chemicals similar in structure to PCP can provide positive results, or cross reactivity.
The PCP immunoassay measures PCP concen-trations in soil and water. For semiquantitative soil analysis, the concentration ranges are as follows: greater than 50 parts per million (ppm), between 50 and 5 ppm, between 5 and 0.5 ppm, and less than 0.5 ppm. For water analysis, the concentration ranges are as follows: greater than 5,000 parts per billion (ppb), between 5,000 and 500 ppb, between 500 and 5 ppb, and less than 5 ppb. These ranges can be customized to a user's needs.
The SITE demonstration occurred in summer 1993 at Morrisville, North Carolina. Samples collected from Winona, Missouri were transported to the demonstration location for testing. Samples from both sites were analyzed to evaluate the effects of different sample matrices and of different PCP carriers such as diesel fuel and isopropyl ether-butane. During the demonstration, the PENTA RISc Test System analyzed 112 soil samples and 16 water samples. The Innovative Technology Evaluation Report (EPA/540/R-95/514), which details results from the demonstration, is available from EPA.
The PENTA RISc Test System has been accepted under Solid Waste Method 4010 (SW-846, third edition, second update). In the 4 years that it has been available, more than 12,000 immunoassay-based tests have been used on wood preserving sites.
EPA PROJECT MANAGER:
Jeanette Van Emon
U.S. EPA
National Exposure Research Laboratory
Characterization Research Division
P.O. Box 93478
Las Vegas, NV 89193-3478
702-798-2154
Fax: 702-798-2261
TECHNOLOGY DEVELOPER CONTACT:
Tim Lawruk
Strategic Diagnostics, Inc.
375 Pheasant Run
Newtown, PA 18940
800-544-8881
215-860-5115
Fax: 215-860-5213