Analytical method development and risk characterisation of anthraquinone in various types of tea

Methods available for analysis of natural and artificial anthraquinone contamination of tea are cumbersome due to the need for expensive equipment and purification for sample preparation. Therefore, herein, a new method based on HPLC-PDA, GC/MS, and the QuEChERS method for sample preparation was developed and validated. Comparison of the performance characteristics and measurement uncertainties revealed an LOD of 0.0038 mg/kg, precision of 0.47–2.51%, and measurement uncertainty of 2.5% for GC/MS and an LOD of 0.15 mg/kg, precision of 0.32–3.75%, and measurement uncertainty of 4.9% for HPLC-PDA; thus, GC/MS was concluded to be the more suitable method. Green tea, oolong tea, black tea, and pu-erh tea were analysed by the developed GC/MS method. The hazard quotient values of exposure to anthraquinone from drinking tea indicated that exposure to anthraquinone from drinking tea does not cause adverse health effects in consumers.