Carbon-14 radioactivity measuring method for determination of carbon-14 activity concentration, involves mixing compound with scintillating liquid, and measuring radioactivity emitted by carbon-14 of compound by liquid scintillation counter

摘要

The method involves acidifying a raw aqueous sample using acid when pH of the sample is higher than 5. An oxidizing agent is added to the sample to oxidize carbonated chemical species into gaseous carbondioxide. The carbondioxide is contacted with a solution containing a reagent i.e. 3-methoxypropylamine, associated with the carbondioxide to form a compound, in a reaction chamber. The compound is mixed with Permafluor E+(RTM: scintillating liquid) i.e. 1, 2, 4 trimethylbenzene, and radioactivity emitted by carbon-14 of the compound is measured by a liquid scintillation counter. The oxidizing agent is chosen from a group comprising persulphate, perchlorate, permanganate and bichromate. The acid is chosen from a group comprising nitric acid, orthophosphoric acid and sulfuric acid. The gaseous carbondioxide traverses a trap to retain halogens and/or tritium.