• • Achieved simultaneous quantification of 11 OUVs in coral tissue with method detection limits (MDLs) of 0.020–0.133 ng·g−1 and quantification limits (MQLs) of 0.080–0.532 ng·g−1, enabling trace-level monitoring essential for assessing bioaccumulation in marine organisms.
• • The optimized extraction protocol (sequential methanol and ethyl acetate, vortexing 20 min, ultrasonication 20 min at 30 °C) yielded recoveries of 60.5%–120.3% across three spiking levels (1, 10, 50 ng·g−1) with RSDs ≤10.7%, demonstrating robustness for complex biological matrices.
• • Chromatographic separation on CAPCELL PAK MG C18 (5 μm, 2.1 mm × 100 mm) at 40 °C with a methanol–0.1% formic acid gradient achieved baseline separation within 15 min, balancing resolution and throughput for routine monitoring.
• • Field application to 89 coral samples from Xidao Island detected five target OUVs, confirming the method's practical utility for environmental surveillance and risk assessment in coral reef ecosystems.