Isotope dilution analysis was applied to determine urinary excretion of fentanyl (FT) and its main metabolite, norfentanyl (Nor-FT), by isotopic fractionation using a capillary gas chromatograph equipped with a surface ionization detector (SID) . Urinary FT was determined quantitatively in the range of 0.4-40 ng/ml using deuterium labeled FT (FT-2H19), as an internal standard. We also performed isotope dilution analysis of Nor-FT in urine. NV Alkylation was necessary to sensitively detect Nor-FT with SID. Methyl derivative was selected from 3 kinds of NV alkyl derivatives to increase sensitivity and peak resolution, and to prevent interference with urinary compound. Nor-FT concentration was quantitatively determined in the range of 10-400 ng/ml using deuterium labeled Nor-FT (Nor-FT-2H10) . No endogenous compounds or concomitant drugs interfered with the detection of FT and Nor-FT in the urine of patients. The present method will be useful for pharmacokinetic studies and the evaluation of drug interactions in FT metabolism.
Atmospheric concentrations of210Pb and7Be were observed in the region of the western Pacific Ocean with aerosol samples collected on board in cruises from Fremantle, Australia, to Kobe, Japan. Observations were carried out during the period from the end of August to early September in 1993 and 1994. The atmospheric concentrations of210Pb and7Be ranged from 0.0 to 1.4 mBq/m3and from 1.1 to 9.5mBq/m3, respectively, and both nuclides exhibited a similar distribution pattern along the two cruising routes. The atmospheric concentrations of both nuclides observed in the 1994 cruising were generally higher than those in the 1993 cruising.
Cd-hem method is the most simple and easy method for the determination of metallothionein (Mt) . In this method, Mt-unbound Cd is removed by a treatment with rat hemoglobin (Hb) and heating at 100 °C. This step is usually repeated 3 times. The authors have carried out several experiments on the Cd-removal process in the Cd-hem method. Bovine and swine Hbs have a high affinity for Cd and are satisfactorily available for the Cd-hem method instead of the rat Hb. Although Mt is not lost by the treatment with Hb and heating at 100°C, only a single treatment is recommended because it is enough for the removal of Mt-unbound Cd. For the accurate determination of Mt, the value of blank which is determined without biological samples should be subtracted from that of biological samples because the Mt-unbound Cd cannot be removed completely by this treatment even though the treatment is repeated 3 times.
Tritiated water vapor from a radioluminous watch was transferred to water in a small vessel situated near the watch through HTO exchange in a short time. From the mathematical transfer model, the concentration of HTO vapor was found to amount to be about 108 Bq/g, which was about 1011 times greater than the environmental background level of tritium in water. The large difference in the specific activity of HTO between the vapor in the air and the water in the vessel caused the prompt increase of HTO concentration in the water.