Identification of halogenated disinfection byproducts of nonylphenol in chlorinated wastewater effluent using novel high resolution GC/Q-TOF

Academic Research Topics in Environmental Measurement and Monitoring
Oral Presentation

Prepared by C. Hoppe-Jones1, S. Nieto2, S. Beitel1, S. Snyder1, N. Eno1
1 - University of Arizona, 1657 E Helen St, Keating Research Building 402, Tucson, ARIZONA, 85721, United States
2 - Agilent Technologies, Inc., , Santa Clara, California, United States


Contact Information: hoppejc@email.arizona.edu; 720-454-7066


ABSTRACT

Nonylphenol (NP) is a mixture of isomers that is being widely used as a detergent and lubricant. It is currently on the US EPA’s Contaminant Candidate List 4 (CCL4). Since wastewater treatment plants are only partially effective in removing NP, ppb levels are being discharged into surface waters. Analysis of disinfection byproducts in wastewater effluent presents a substantial challenge due to extreme complexity of wastewater extracts. Both high sensitivity as well as high MS resolving power are often necessary to identify trace amounts of the water contaminants.
NP in a buffered system and wastewater effluent containing bromide and iodide was oxidized with three commonly used disinfectants; chlorine, monochloramine, and chlorine dioxide. Exposure times were between 10 minutes to 5 hours. Samples were extracted by SPE for GC and bioassay analysis. GC data were acquired using a novel 7250 high resolution GC/Q-TOF system. MassHunter Qualitative Analysis “Find-by-Formula” tool as well as Unknowns Analysis were used for targeted and untargeted data analysis, respectively. Compound identification was performed using NIST14 EI library. To further evaluate the genotoxicity of the sum of DBPs in each sample, p53-bioassays were analyzed for each of the extracts.
To identify disinfection byproducts in the disinfected nonylphenol-containing effluent, the target formula list was created. The target list included the formulas that corresponded to halogenated nonlyphenols (NP) as well as halogenated phenols (Ph). Following chlorination, we identified eight different of mono- and di-halogenated nonylphenol isomer groups and five halogenated phenols. To identify additional byproducts, in addition to the targeted approach described above, the extracts were also analyzed in Unknowns Analysis. Untargeted analysis resulted in additional disinfection byproducts putatively identified by NIST library matching. Bioassay results showed that extracts from experiments disinfected with monchloramine did not show any response in the p53 bioassay, while samples from experiments using chlorine and chlorine dioxide showed toxicity.