中性子放射化分析法による大麻中のリンの定量-³²Pの液体シンチレーションスペクトロメーターによるチェレンコフ光測定-

抄録

Thermal neutron activation analysis with measurement of ³²P Cerenkov radiation by liquid scintillation spectrometer was used to determine phosphorus in cannabis. After irradiation of the sample, wet ashing was carried out with conc. nitric acid and 70% perchloric acid. The solution in 1M perchloric acid transferred to an inorganic ion-exchange column containing acid aluminum oxide and phosphorus was quantitatively eluted with 1M hydrofluoric acid. The ³²P radioactivity of each fraction of the eluate was counted with Cerenkov radiation by a liquid scintillation spectrometer from 2 to 7 weeks after the irradiation. The activity curve decayed with ³²P half-life. The isotope channel ratio technique was applied for the quench correction. The values for upper and middle leaves, and male flower of cannabis, in parts per million, were 0.55, 0.31, and 0.71, respectively, and a good agreement was found with the values from Molybdenum Blue method. The determination limit of phosphorus by this method was calculated to be 2.5×10^-8g. The optimal experimental conditions for chemical separation of phosphorus and for measuring the ³²P Cerenkov radiation were also examined.