In14Cdating by LSC system, benzene is usually synthesized from collected samples via several chemical reactions such as pretreatment, carbonization, combustion, carbonating, carbide production, acetylene generation and polymerization. Since a great deal of efforts is required to the sample preparation, we proposed an another rapid process where the carbonized samples reacted to melted lithium metal directly to produce lithium carbide. Although the yield generating acetylene gas from carbonized samples was low, 52.5±1.5% on average, the yield synthesizing benzene from acetylene was 90% or more in the successive process. Some impurity atoms contained in carbonized samples deteriorate apparently the yield generating acetylene but they did not influence the yield synthesizing benzene from acetylene. This shows that combustion is not indispensable process in14Csample preparation. 14Cages for the samples prepared by the proposed method were agreed to those for the same samples prepared by the conventional method within the age variation corresponding to the statistical error of 1σ.Therefore the fractionation effect of carbon isotopes may be low, if any, in the proposed process. Since this method does not contain combustion and the following carbonating process, the sample preparation is fairly shortened.
We studied the performance of“Ready Cap”solid scintillator developed for the liquid scintillation counter, by using45Ca which is usually employed to deduce intracellular signaling by the tracer method. The liquid scintillators“AQUASOL-2”and“ATOMLIGHT”were used for comparison. Our findings were as follows: (1) A high counting efficiency of over 90% was achieved with the wide range of 200 to 106dpm, (2) measurement errors due to the uneven resolution of the solid scintillator and/or due to contents such as biological high polymers causing a hindrance in scintillation process were revealed to be low at below 5.3%, and (3) minimal effects were observed on (1) and (2) above even when actual samples containing biological high polymers and cell extracts with biopolymers detergent agent were used. We conclude that the solid scintillator studied here is practically enough useful for liquid scintillation measurement required in biological experiments.