27.2.1 Reagents

Ultrapure grade NaOH solution (3 M) was purchased from Kanto Kagaku. Ultrapure grade of tetramethyl ammonium hydroxide (TMAH) solution was pur­chased from Tama Chemicals. The other reagents were all analytical grade or higher and purchased from Wako Chemical. Empore solid extraction disks, Anion-SR, were purchased from 3 M. Standard solution of 129I (35.8 kBq/g 129I; chemical composition, 50 Fg/g NaI and 50 Fg/g Na2S2O3 in H2O) was purchased from AREVA and diluted with H2O before use. Potassium iodide (analytical grade,

99.9 %) and KIO3 (analytical standard material grade, 99.98 %) were purchased from Wako Pure Chemical Industries, and ‘I and ‘IO3 were prepared from these reagents, respectively, because the stable iodine isotope is only 127I.