Study on acid digestion method for barium carbonate precipitate with variation of acids in chemical analysis of C-14

In our atmosphere, 0.04% carbon-di-oxide is present along with other gases. There is a fixed ratio of ¹²C (stable isotope) and ¹⁴C (radioisotope). ¹⁴C, pure beta emitter with Bmax 156 keV and average energy of 52 keV, decays into the stable (non-radioactive) isotope ¹⁴N. ¹⁴C, is produced via path route of ¹⁴N(n,p)¹⁴C, ¹³C(n,r)¹⁴C and ¹⁷O(n,A)¹⁴C. Amount of ¹⁴C present in air can be estimated by proper sampling and chemical analysis. Air sample can be passed through different sorbing mediums like sodium hydroxide, amines, hydroxyl amines to exchange carbon-di-oxide within the solution. 2 (N) NaOH solution is taken as standard sorbing medium, which is a established method. Carbon-di-oxide reacts with sodium hydroxide solution to form sodium carbonate. In order to avoid the interference of tritium, barium carbonate precipitate is obtained with chemical reaction of barium chloride and sodium carbonate, followed by digestion with lactic acid solution. Evolved radioactive carbon-dioxide gas was trapped into another sorbing medium (ethanolamine and methanol mixture). This organic mixture was analysed in liquid scintillation counter for quantification of ¹⁴C. In order to assess the effect of different acids in digestion method of barium carbonate, acids with different density (organic and inorganic acids) were used. The variability study of acids during digestion method is presented in the paper