Fluorine and aluminum content in tea leaf

Fluorine and aluminum concentrations of tea leaves have been measured over the growth period from one month to twelve months simultaneously by the proton induced gamma-ray emission (PIGE) method. The 2.49 MeV proton beam was used and the concentrations of fluorine and aluminum were evaluated from the ¹⁹F(p, αγ)¹⁶O 6.1 MeV photon and its two escape yields and ¹³Al (p, p'γ)¹³ Al 1.104 MeV photon yields, respectively. Change of aluminum concentrations showed similar increase pattern obtained last year. While the fluorine concentration showed large dispersion with growth period and no clear dependence on the growth period was observed. (author)