Study on the contamination level and dietary exposure of 9,10-anthraquinone in different types of teas in Wuhan / 公共卫生与预防医学

ABSTRACT

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（150）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.