Contents of 4-Nonylphenol in Surface Sea Water of Amur Bay (Japan/East Sea)

The determination of 4-nonylphenols has been developed using HPLC with fluorescence detection method. 4-Nonylphenols in sea water samples were extracted using a liquid–liquid extraction. Acidification and adding salting-out agents (NaI) of water samples increased the extraction degree. The extraction of 4-nonylphenols was done twice with 20 mL of methylene chloride. The applied concentrated range was over 5–1000 ng/mL for the 4-nonylphenol. The recovery test ranged from 78.5 to 89.9% with relative standard deviations between 1.0 and 7.5% of 100 ng/mL of the standard phenols spiked with the water sample and the detection limit was 1 ng/mL. The proposed method was applied satisfactorily for the determination of 4-nonylphenole in sea water samples. Levels of 4-nonylphenol were determined in the sea waters of the Amur Bay. Water samples were collected every year from 2008 to 2015. Concentrations of 4-nonylphenol in the waters ranged from levels below the detection limits up to 1.24 μg/L.