DEVELOPING ANALYTICAL PROTOCOLS FOR 6PPD-Q IN NATURAL WATERS

6PPD-quinone (6PPD-Q), as an oxidized product of 6PPD, is highly toxic and causes the acute mortality of coho salmon (Oncorhynchus kisutch). However, analyzing 6PPD-Q in natural waters can be challenging due to its amphiphilic properties and interference with natural particles and dissolved organic matter. In this study, we sought to develop a streamlined protocol of extracting and analyzing 6PPD-Q in natural waters. We tested how different types of solid phase extraction (SPE) cartridge, filter size, and salinity affected the extraction efficiency of 6PPD-Q in seawater using LC-MS. Also tested were the effects of solvent (ACN vs DMSO), freezing and thawing of DMSO, sonication, and bottle type (plastic vs glass) on the measured concentration of 6PPD-Q. For seawater samples, pre-filtration through 0.2 µm filters and Oasis Prime HLB delivered the best recovery rates of 6PPD-Q, while salinity had no significant effect. Sonicating as well as freezing and thawing samples in DMSO improved recovered 6PPD-Q concentrations, and the measured concentration of 6PPD-Q was higher when using glass bottles. The matrix in which 6PPD-Q is prepared makes a difference: DMSO increased the responding factor of 6PPD-Q in LC-MS compared with ACN, and the effect was most pronounced at higher 6PPD-Q concentrations. Recommended instrumental conditions are suggested, such as mobile phase, column, m/z ratio, and linear range. Finally, field data utilizing these methods are presented. Overall, this work provides an efficient streamlined protocol for extracting and analyzing 6PPD-Q in natural waters.

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Primary Presenter: Jack Lloyd, The University of Texas at Austin (jack.lloyd@utexas.edu)

Authors:

Jack Lloyd, The University of Texas at Austin  (jack.lloyd@utexas.edu)

Kaijun Lu, The University of Texas at Austin  (kaijun.lu@utexas.edu)

Kerri Ackerly, The University of Texas at Austin  (klackerly@utexas.edu)

Kristin Nielsen, The University of Texas at Austin  (kristin.nielsen@austin.utexas.edu)

Andrew Esbaugh, The University of Texas at Austin  (a.esbaugh@austin.utexas.edu)

Zhanfei Liu, The University of Texas at Austin  (zhanfei.liu@utexas.edu)