Pagano Todd, Biacchi Adam J, Kenny Jonathan E
Department of Science and Mathematics, Laboratory Science Technology Program, Rochester Institute of Technology, National Technical Institute for the Deaf, 52 Lomb Memorial Drive, Rochester, New York 14623, USA.
Appl Spectrosc. 2008 Mar;62(3):333-6. doi: 10.1366/000370208783759696.
During routine fluorescence analysis, the presence of dissolved oxygen in solutions can result in the dynamic quenching of a fluorophore's emission through collisional deexcitation of the fluorophore's excited state. In order to avoid this type of fluorescence quenching, dissolved oxygen is often removed from solutions by an inert gas purging procedure. However, the details and quantification of this purging process are often limited in fluorescence studies. In this work, standard 10 mm x 10 mm fluorescence cuvettes are filled with polyaromatic hydrocarbon (PAH) solutions in cyclohexane and purged using nitrogen gas, and the experimental purging parameters (nitrogen flow rate, amount of volatile solvent loss, and rate of oxygen removal) are measured and analyzed. For experimental conditions similar to those used in this study, we are able to provide useful guidelines for the deoxygenation of solutions, specifically the purge times required for solutions of fluorophores with various fluorescence lifetimes. Enhancement factors, or F(0)/F values (the ratio of fluorescence intensity of a completely deoxygenated solution to the fluorescence intensity of an aerated solution), for chrysene, phenanthrene, naphthalene, and pyrene solutions in cyclohexane were found to be 3.61 +/- 0.02, 4.17 +/- 0.02, 7.63 +/- 0.07, and 21.81 +/- 0.35, respectively.
在常规荧光分析过程中，溶液中溶解氧的存在会通过荧光团激发态的碰撞去激发作用导致荧光团发射的动态猝灭。为了避免这种类型的荧光猝灭，通常通过惰性气体吹扫程序从溶液中去除溶解氧。然而，在荧光研究中，这种吹扫过程的细节和定量往往受到限制。在这项工作中，将标准的10毫米×10毫米荧光比色皿装满环己烷中的多环芳烃（PAH）溶液，并用氮气吹扫，测量并分析了实验吹扫参数（氮气流速、挥发性溶剂损失量和氧气去除率）。对于与本研究中使用的条件相似的实验条件，我们能够为溶液的脱氧提供有用的指导方针，特别是对于具有不同荧光寿命的荧光团溶液所需的吹扫时间。发现环己烷中蒽、菲、萘和芘溶液的增强因子或F(0)/F值（完全脱氧溶液的荧光强度与曝气溶液的荧光强度之比）分别为3.61±0.02、4.17±0.02、7.63±0.07和21.81±0.35。
