Determination of fluoride content in tea and tea beverage by activated carbon purification-ion chromatography and its health risk assessment
Objective To establish a method for the determination of fluoride ion in tea and tea beverages by activated carbon purification-ion chromatography,and then to study the health risks of tea water and tea beverages.Methods The experiment was carried out by brewing 6 kinds of tea in 2 ways respectively.Method 1:Tea was brewed in a time gradient.Method 2:Add tea once,brew tea with several times and then collect tea.Collect tea by brewing tea with water several times.The tea and tea beverages were purified by activated carbon,filtered by 0.45 μm microporous filter membrane,separated by AS23 ion chromatographic column(4.0 mm×250 mm)with 4.5 mmol/L Na2CO3 and 0.8 mmol/L NaHCO3 solution as leach solution,and tested by ion chromatography.The health risk was assessed by the highest tea fluoride dissolution with method 1,the total tea fluoride dissolution with method 2 and tea fluoride content in tea beverages.Results Under the optimal analysis conditions,the limit of detection of fluoride ions was 0.016 mg/L.In the range of 0.1-5.0 mg/L,the linear relationship was good,the correlation coefficient(r2)was 0.9996,the recovery rates were 94.93%-105.32%,the relative standard deviations were 1.02%-2.13%(n=6).The method detected the amount of fluoride ion dissolved in tea,and found that the dissolution increased continuously with the extension of brewing time and reached the highest value.With the increase of brewing times,the dissolution of fluoride ion in tea increased first,and then the decline trend gradually slowed down.The dissolution rate of fluoride ion in the first 2 brewing times reached more than 65%of total dissolution.Conclusion The method has high sensitivity,good accuracy,simple operation and practical value.Daily intake of tea fluoride in tea and tea beverages obtained from 6 kinds of tea under 2 brewing methods are in line with the daily intake limit of fluoride recommended by China and the World Health Organization.The target hazard quotient(THQ)values are less than 1,and there is no significant health risk to human.It is recommended to reduce tea brewing time,wash tea,and choose high-quality tea to drink tea scientifically and healthily.
万方数据
维普
