Radiocarbon dating by methanol LSC method

Several experiments for developing of radiocarbon dating by methanol-LSC method were done: (1) Measurement of C-14 content in NIST oxalic acid standard, (2) The test for contamination by contemporary C-14 atoms during methanol preparation and (3) the cross check of our data with those obtained by other researchers. The weighted mean value of 11 times measurements of C-14 content in NIST oxalic acid standard is 18.27 ± 0.024 dpm/gC, which is well consistent with the public value, 18.36 ± 0.15 dpm/gC. It is found that the contamination by the C-14 atoms is negligible in the procedure. Cross checks show that our data are good agreement with those obtained by other researchers within 2 sigma %. The reliability of our method is well verified with the results described here. (author)