Comparison of O-SPE and Using Liquid Chromatography Tandem Mass Spectrometry for the Detection of Trace Organic Compounds in Surface Waters, Wastewater Effluents, and Advanced Treatment Effluents

Oral Presentation

Prepared by K. Daniels, G. Flores, A. Nienhauser, J. Ordine, S. Snyder
University of Arizona, 1657 E. Helen St., Tucson, Arizona, 85719, United States


Contact Information: kddaniels@email.arizona.edu; 760-705-0828


ABSTRACT

Increasing human populations, climatic shifts, and environmental degradation have caused water shortages and drought in many regions of the world. This has led to the pursuit of alternative water supplies capable of alleviating water deficits. Of the common water alternatives, water reuse is applied the most. In the United States, wastewater treatment plants typically apply conventional treatment methods and release effluents into an environmental buffer. This process is known as indirect potable reuse (IPR). Wastewater effluents from IPR processes have most, but not all contaminants removed. Of the remaining contaminants, trace organic compounds (TOrCs) have been frequently detected at concentrations that raise questions about environmental and human health implications. In addition to IPR, there is an additional water reuse method known as direct potable reuse (DPR). Using advanced treatment techniques, DPR purifies wastewater to a high enough quality that it can be directly introduced into a city’s water supply. Thus, between the current and growing applications of water reuse, there is a need for fast and accurate quantification of TOrCs.

The purpose of this study is to compare two different analytical methods capable of quantifying TOrCs in different water matricies. Due to the low concentrations of TOrCs in various water matricies, conventional liquid chromatography mass spectrometry methods using solid phase extraction for sample enrichment are often applied, but are time consuming. Online-solid phase extraction (O-SPE) and direct water injection (DWI) reduce the amount of time to analyze a sample by eliminating the conditioning, loading, drying, and eluting steps that were done manually before the sample is ready to be evaporated down and raised in the necessary solvent before instrument injection. Altogether, quarterly samples from multiple surface waters, wastewater effluents, advanced treatment steps, and DPR final effluents were analyzed using the O-SPE and DWI methods. Both methods were effective in quantifying the selected TOrCs and displayed similar results.