Environmental status and early warning value of the pollutant Semicarbazide in Jincheng and Sishili Bays, Shandong Peninsula, China

- An ultra performance liquid chromatography-tandem mass spectrometry was developed for determining Semicarbazide, with short time, high sensitivity and accurate characterization.
- The temporal and spatial distribution of Semicarbazide in seawater was measured and the highly polluted areas identified and traced.
- The distribution of Semicarbazide in sediment and shellfish was also analyzed.
- An early warning value 0.05 μg/L in seawater was deduced.

A verified method for measuring Semicarbazide (SEM) in seawater, sediments, and shellfish was developed based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). A total of 30 stations were radially distributed in Jincheng and Sishili Bays in the Bohai and Yellow Seas, and 1025 monitoring data were collected in 41 voyages, 615 seawater samples, 320 sediment samples and 90 shellfish samples. The concentration ranged from 0.011 μg/L to 0.093 μg/L and 0 to 0.75 μg/kg in seawater and shellfish respectively, but SEM in sediment was all below the limit of detection. Temporal and spatial distribution of SEM was investigated using multivariate analysis to estimate the degree of SEM pollution. Based on the SEM concentration in the three sample types, together with our previous findings, early warning values were deduced for SEM in seawater, and the developed method overcame shortcomings with existing technologies. The results may be helpful to draft national baseline values for SEM in seawater and sediments, and provide a scientific basis for assessing the impacts of SEM on marine ecology and human health.

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