[17a-418-1~10] 3.8 Optical measurement, instrumentation, and sensor

▲ [17a-418-9] Cavity Ring-Down Spectroscopy for ¹⁴C Isotope Analysis of Biomedical Samples

〇(P)Volker Thomas Sonnenschein¹, Ryohei Terabayashi¹, Hideki Tomita¹, Noriyoshi Hyashi¹, Shusuke Kato¹, Lei Jin¹, Masahito Yamanaka¹, Norihiko Nishizawa¹, Atsushi Sato², Kohei Nozawa², Kenta Hashizume², Toshinari Oh-hara², Tetsuo Iguchi¹ (1.Nagoya Univ., 2.ADME & Tox. Research Inst., Sekisui Medical, Tokai, Ibaraki)

Keywords:molecular spectroscopy, cavity, 14C

High sensitivity techniques such as Accelerator Mass spectrometry are commonly used for detection of the radioisotope ¹⁴C. In the environment, its abundance is typically at the ppt level, however in medical samples, where it is used as tracer isotope to study the metabolism of subjects or other biological processes, the abundance can be significantly higher. Detection may then be performed by application of optical methods such as Cavity Ring-Down Spectroscopy (CRDS), thus providing a more compact and inexpensive solution as well as possibilities for in-field measurements.
We have built a compact CRDS system working in the Mid-infrared and show first results of spectroscopy of ¹⁴CO₂ in biomedical samples (plasma / urine).