Biological and biomedical 14C-accelerator mass spectrometry and graphitization of carbonaceous samples

Abstract

Accelerator mass spectrometry (AMS) is the ultimate technique for measuring rare isotopes in small samples. Biological and biomedical applications of (14)C-AMS (bio-(14)C-AMS) commenced in the early 1990s and are now widely used in many research fields including pharmacology, toxicology, food, and nutrition. For accurate, precise, and reproducible bio-(14)C-AMS analysis, the graphitization step in sample preparation is the most critical step. So, various sample preparation methods for a process called graphitization have been reported for specific applications. Catalytic graphitization using either a flame-sealed borosilicate tube or a septa-sealed vial is a popular sample preparation method for bio-(14)C-AMS. In this review, we introduce the AMS system, especially for bio-(14)C-AMS. In addition, we also review the graphitization method for bio-(14)C-AMS to promote further understanding and improvement of sample preparation for this technique. Examples of catalytic graphitization methods over the past two decades are described.

Application of zinc sealed tube graphitization on sub-milligram samples using EnvironMICADAS

“…Recently we have adopted an alternative sealed tube method for 1 mg carbon sample size, where the zinc reagent is used as sole reduction agent (Zn-method) [9][10][11] and optimized it for the MICADAS AMS instrument (under publication). This alternative method has already been successfully applied and used in other labs for micrograms sample size [12][13][14].…”

Radionuclide Monitoring

“…Gas proportional counter (GPS) has been used for both 3 H and 14 C but with less (Gröning et al, 2009;Theodorsson, 1991). Accelerator mass spectrometry (AMS) measurement for 14 C is very widely applied for low-level environmental samples (Chung and Kim, 2013). Attempt has also been made for AMS measurement of 3 H based on the decay product 3 He, however, this method seems not to have won wide acceptance.…”

Flame-Sealed Tube Graphitization Using Zinc as the Sole Reduction Agent: Precision Improvement of EnvironMICADAS 14C Measurements on Graphite Targets

“…sealed vial graphitization method, where zinc alone is used as the reduction agent, has been developed for biological and biomedical applications (Kim et al 2008;Chung and Kim 2013). However, lower ion current and higher background level are disadvantages of that method.…”