Background: Populations of Indo-Pacific humpback dolphins (Sousa chinensis) in China were known to be distributed from the Beibu Gulf near the border with Vietnam to the mouth of the Yangtze River. According to existing studies, the waters around Hainan Island, China, were not considered to be part of the humpback dolphins' distribution. Results: In 2014, for the first time, we recorded humpback dolphins in waters southwest of Hainan Island.

a b s t r a c tIn this study, dispersive liquid-liquid microextraction (DLLME) combined with ultra-high-pressure liquid chromatography (UHPLC)-tunable ultraviolet detection (TUV), has been developed for pre-concentration and determination of triclosan (TCS), triclocarban (TCC) and methyl-triclosan (M-TCS) in aqueous samples. The key factors, including the kind and volume of extraction solvent and dispersive solvent, extraction time, salt effect and pH, which probably affect the extraction efficiencies were examined and optimized. Under the optimum conditions, linearity of the method was observed in the range of 0.0500-100 g L −1for TCS, 0.0250-50.0 g L −1 for TCC, and 0.500-100 g L −1 for M-TCS, respectively, with correlation coefficients (r 2 ) > 0.9945. The limits of detection (LODs) ranged from 45.1 to 236 ng L −1 . TCS in domestic waters was detected with the concentration of 2.08 g L −1 . The spiked recoveries of three target compounds in river water, irrigating water, reclaimed water and domestic water samples were achieved in the range of 96.4-121%, 64.3-84.9%, 77.2-115% and 75.5-106%, respectively. As a result, this method can be successfully applied for the rapid and convenient determination of TCS, TCC and M-TCS in real water samples.