Abstract: Disclosed is a method for concentrating by 20 to 10,000 fold a semivolatile or essentially nonvolatile organic compound, such as a herbicide or pesticide, from a contaminated aqueous solution into a carrier fluid for simultaneous or subsequent analysis. A perstraction membrane is contacted on one surface with a large volume of an aqueous feedstream containing a low concentration of an organic compound, and an opposite surface of the same membrane is contacted with a small volume of a carrier fluid. The perstraction membrane is characterized by a nonporous layer therein which precludes convective flow and mixing between the aqueous and carrier fluid phases. The organic compound is absorbed into the nonporous skin layer from the aqueous fluid and is transferred from the nonporous skin layer into the carrier fluid by an affinity driving force, the affinity of the carrier fluid for the organic compound being greater than the affinity of water for the same compound.

Abstract: An apparatus for the treatment of articles with a polymerizate-producing gas plasma is disclosed wherein a set of movable film liners is used to shield the walls of a gas-plasma-containing reaction tunnel from excessive build-up of polymerizate deposits. In an operation involving continuous gas plasma coating of a film, fiber, fabric, tubing or string of workpieces, at least 75 to 90 percent of potential wall deposits are removable by the set of film liners.