Saturation units for use in aquatic bioassays

Methods were developed for preparing liquid/liquid and glass wool column sa turators for generating chemical stock solutions for conducting aquatic bio assays. Exposures have been conducted using several species of fish, invert ebrate, and mollusks in static and flow-through conditions using these meth ods. Stock solutions for 82 organic chemicals were prepared using these sat uration units. The primary purpose of stock generation was to provide a con tinuous and consistent amount of toxicant laden solution at a measured anal ytical level which would be available to test organisms for the test durati on. In the present study, the glass wool column and liquid/liquid saturator s were used to provide consistent stock concentrations, at times approachin g saturation, for fathead minnow (Pimephales promelas) acute exposures. Att empts were made to achieve the maximum solubility of these compounds for co mparison purposes to water solubility values available in the literature. L iterature solubility values from a database by Yalkowsky et al. [1] provide d information on temperatures and data quality which allowed comparison to values obtained from the present study. Twenty four compounds were identifi ed and analyzed for the comparison of maximum obtainable solubility levels. Maximum saturator stock water concentrations were generally lower (R=0.98) but were in close agreement with published water solubility values. (C) 19 99 Elsevier Science Ltd. All rights reserved.