Determination of the time-dependent OH-yield by using a fluorescent probe. Application to heavy ion irradiation

• DOI: 10.1016/j.cplett.2008.12.006
• Publication Date: 2008-12-09T10:12:24Z
• Authors: G. Baldacchino; T. Maeyama; S. Yamashita; M. Taguchi; A. Kimura; Y. Katsumura; T. Murakami
• Keywords: 0301 basic medicine; 03 medical and health sciences

Abstract This Letter reports a sensitive method using HPLC-Fluorescence detection of • OH in liquid water under high-energy heavy ion irradiation. The coumarin-3-carboxylic-acid (3CCA) molecule was selected for probing • OH and providing the fluorescent 7-hydroxy-coumarin-3-carboxylic-acid (7OH-3CCA). Since the concentration limit achievable is better than 1 nM, the radiolytic yields were determined with a sensitivity of 2 × 10 −9 mol/J for 4.8 GeV- 12 C 6+ of and 20 GeV- 40 Ar 18+ in the ns time range. They decrease with the linear energy transfer from 2.8 × 10 −7 to 1.3 × 10 −7 mol/J (C 6+ of 11 eV/nm) and 1.5 × 10 −7 to 0.9 × 10 −7 mol/J (Ar 18+ of 90 eV/nm) which is in agreement with the literature data.