Exploring the Great Unknown: New Tools to Assess Complex Environmental Mixtures

Oral Presentation

Prepared by S. Snyder
University of Arizona - Chemical & Environmental Engineering, 1133 E. James E. Rogers Way, Room 108, Tucson, AZ, 85721, United States

Contact Information: snyders2@email.arizona.edu; 520-621-2573


Around the globe, human population continues to grow and urbanize. Population density in major urban zones is often growing at rates that demand water supplies which natural recharge cannot fulfil. For both coastal and inland communities, reuse of municipal wastewater is a viable option for extending water supplies. However, water quality constituents, in general, are different in alternative water supplies and can lead to unique formation and speciation of byproducts during oxidative water treatment. There are more than 65 million chemicals available commercially with an innumerable amount of transformation products. While modern analytical techniques can selectively and sensitively identify specific trace levels of contaminants in water, the procedures utilized are historically time-consuming, labour-intensive, and technically-sophisticated. However, new techniques are rapidly evolving to measure trace levels of chemicals with automated and/or minimum sample preparation. For instance, automated solid-phase extraction coupled to liquid chromatography with tandem mass spectrometry and solid-phase microextraction (SPME) coupled to gas chromatography with mass spectrometric detection offers rapid screening of a broad diversity of chemical structure. In addition to monitoring indicator compounds that provide specific information regarding watershed contamination and treatment process efficacy, high-resolution quadrupole mass spectrometry (QTOF) coupled to both GC and LC interfaces can provide both targeted analytic information while simultaneously acquiring full mass spectra that allows a more comprehensive view of the complex chemical mixtures and results transformation products in water. Another technique that has been recently utilized for characterizing environmental samples is inductively-coupled plasma mass spectrometry (ICP/MS), which can be interfaced with GC and LC to provide atomic composition information. As an example, GC-ICP/MS has been demonstrated to effectively screen for potentially toxic iodinated and brominated disinfection byproducts resulting from chlorination of water. Coupled with high-throughput bioassays, these techniques provide a new view as to the complex mixtures occurring in the environment and their potential impacts to health. This presentation will show how these methods have been developed and utilized to characterize water that is recycled for drinking through advanced water treatment processes.