Decontaminating materials used in ground water sampling devices: Organic contaminants

In these studies, the efficiency of various decontamination protocols was t ested on small pieces of materials commonly used in ground water sampling d evices. Three materials, which ranged in ability to sorb organic solutes, w ere tested: stainless steel (SS), rigid polyvinyl chloride (PVC), and polyt etrafluoroethylene (PTFE). The test pieces were exposed to two aqueous test solutions: One contained three volatile organic compounds (VOCs) and one n itroaromatic compound. and the other contained four pesticides. Also, three types of polymeric tubing were exposed to pesticide solutions. Generally, the contact times were 10 minutes and 24 hours for sorption and desorption. The contaminants were removed from the nonpermeable SS and the less-sorptiv e rigid PVC test pieces simply by washing with a hot detergent solution and rinsing with hot water. Additional treatment was required for the PTFE tes t pieces exposed to the VOCs and for the low-density polyethylene (LDPE) tu bing exposed to the pesticide test solution. Solvent rinsing did not improv e removal of the three VOCs from the PTFE and only marginally improved remo val of the residual pesticides from the LDPE. However a hot water and deter gent wash and rinse followed by oven drying at approximately 105 degrees C was effective for removing the VOCs from the PTFE and substantially reduced pesticide contamination from the LDPE.