A field screening method for polychlorinated biphenyl compounds in water
The objective of this study was to develop a simple, inexpensive and rapid procedure for determination of PCBs in water. There was special interest in developing a field-screening procedure for aqueous extracts resulting from a soil remediation procedure; the extracting liquid typically contains 1-3% PCBs by weight to enhance the solubility of PCBs. A test was developed based on forming complexes of PCBs with Ag{dollar}\sp+{dollar} followed by UV irradiation to form Ag metal. The appearance of color (gray to brown depending on the PCB concentration) was used to signal the presence of PCB. The test color can be directly compared to standard color charts to give an estimate of the PCB concentration level without the need for instrumentation. In addition to soil remediation monitoring, potential applications include well monitoring, wellhead protection monitoring, post-closure monitoring and rapid laboratory screening. For applications related to soil remediation, it was found that filter papers or SPE membranes could be used in a dipstick mode by spraying with methanolic AgNO{dollar}\sb3{dollar} and irradiation with 254 nm light from a hand portable UV light. The detection range was 1.0-500 ppm (or higher) in the presence of 3% Renex KB or Neodol (R) 1-7; which surfactants are currently being used for PCB soil remediation.
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