Abdul Ghaffar* and Masaaki Tabata Pages 136 - 143 ( 8 )
Radiocarbon dating of an archeological parchment sample was carried out by carbosorb and benzene synthesis methods. The sample, with few symbolic letters written on it, was claimed to belong to the Harappa civilization (ca. 3000-1500 BC).
Objective: Carbosorb and benzene synthesis methods were optimized for radiocarbon dating of parchment samples. Radiocarbon analysis conditions were optimized for liquid scintillation counter.
Methods: Archeological parchment sample and a commercial parchment sample (control sample) were processed by chemical and carbonization methods to remove inorganic and organic impurities. Samples were converted into carbamate and benzene through carbosorb and benzene synthesis systems, respectively. The conditions were optimized to achieve 74 % efficiency of carbosorb method and 78% yield in benzene synthesis system.
Results and Conclusion: The pMC of both samples were calculated by using statistical templates. The fractionation in 14C for sample was corrected for and normalized to 13C composition of -25 ‰ PDB by measuring the 13C composition of the sample, standard and background samples.
The pMC of parchment sample, claimed to belong to old civilization, was calculated as 119.3±1.4 in case of carbosorb method and 118.6 ±2.1 in case of benzene synthesis system. Whereas, the commercial parchment sample showed pMC=121±3.4 for carbosorb method and pMC= 123±4.1 for benzene synthesis method. The age of parchment sample was equal to 1958-1962 AD, when bomb NH3 calibration curve was applied. Based on results, it was concluded that archeological sample was indeed have the post 1950 origin and thus has nothing to do with ancient Harappa civilization.
Benzene synthesis method, carbosorb method, LSC, parchment samples, radiocarbon analysis, lime.
Isotope Application Division, PINSTECH, P.O. Nilore, Islamabad, Faculty of Science and Engineering, Saga University, Saga City