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Objective To investigate the pollution level of 9,10-anthraquinone in teas sold in Wuhan, and to assess the dietary exposure of 9,10-anthraquinone ingested through tea. Methods The content of 9,10-anthraquinone in teas collected from local tea markets in Wuhan was analyzed by GC-MS/MS. Results 9,10-anthraquinone was detected in all 36 tea samples with a concentration ranging from 0.0080 mg/kg to 0.137 mg/kg. The standard limit for 9,10-anthraquinone has not yet been set in China. Referring to EU standards, the total over-standard rate was 86.11% (31/36). Generally, the concentration of residual 9,10-anthraquinone was higher in highly fermented teas. The highest average concentration of residual 9,10-anthraquinone was found in fully/post-fermented tea (0.0762 mg/kg), and the over-standard rate was 100%. The second highest was in semi-fermented tea (0.0452 mg/kg), and the over-standard rate was 86.7%. The concentration of 9,10-anthraquinone in non-fermented tea was 0.0262 mg/kg, and the over-standard rate was 42.9%. According to people’s tea-drinking habits, tea samples were brewed with boiling water（1:50）for 5 minutes, and the concentration of 9,10-anthraquinone in tea soup was 0.0004 mg/kg～0.01 mg/kg, with an average leaching rate of 7.2%. The average daily intake exposure of tea for an adult was 0.0551μg/kg bw/day. Conclusion There was a certain degree of 9,10-anthraquinone pollution in the teas sold in Wuhan, and the rate exceeding the standard was high. Since the acceptable daily intake (ADI) for 9,10-anthraquinone has not been established, it is impossible to assess the health risks of 9,10-anthraquinone ingested through tea.
RESUMO
Medical vacuum knife (MVK) is a new approach for liver surgery. This paper introduces its principles and applications. Some detailed issues related to MVK are also presented such as its differences from other methods, its development and application perspective to abdominal surgery.