For over 20 years, coho salmon populations in Washington State's Puget Sound have suffered unexplained mass die-offs. Some populations are now listed as endangered or threatened. The cause: stormwater runoff from roads carrying 6PPD-Quinone, a transformation product of the tire rubber antioxidant 6PPD that forms when tyres react with ground-level ozone.
6PPD-Quinone is lethal to juvenile coho salmon at concentrations as low as 0.094 ng/mL. Detecting it in tissue at relevant levels demands serious extraction and cleanup chemistry.
Testing for PPD transformation products is growing rapidly. Tyre manufacturers and ecotoxicologists are evaluating alternative p-phenylenediamine compounds (CPPD, 7PPD) as potentially safer substitutes for 6PPD. That means labs need methods that can screen multiple PPD-quinones simultaneously in complex biological matrices.
UCT developed a purpose-built QuEChERS extraction, cleanup, and LC-MS/MS method for multiple PPD-quinones in salmon tissue. The challenge: salmon tissue contains up to 16% fat, heavy carotenoid pigmentation, and co-extractives that suppress ionisation and obscure trace-level analytes.
After QuEChERS extraction, samples pass through three UCT push-thru cartridges in series:
This layered approach is what gets you from a 16% fat matrix to a clean extract suitable for trace-level quantitation.
Extracts are separated on a core-shell C18 HPLC column by LC-MS/MS. 6PPD-Quinone is quantitated using extracted isotope dilution; remaining PPD-quinones use an extracted internal standard. Matrix-matched calibration with LOD/LOQ studies confirms accuracy and precision.
That's sub-lethal sensitivity from one of the fattiest, most pigmented biological matrices you'll encounter in environmental toxicology.
The home of chromatography consumables. We carry UCT's full QuEChERS range, push-thru cleanup cartridges (Quick QuEChERS, C18, LipiFiltr), and core-shell analytical columns. High-quality consumables at unrivalled prices, making your lab budget go further.
We're so much more than chromatography. Whether you're testing PPD-quinones in fish tissue, pesticides in food, or emerging contaminants in environmental matrices, we supply the sorbent combinations that deliver clean extracts and defensible data. Talk to us about method-specific cartridge bundles and bulk pricing.
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