STTR Phase I: Raman Spectroscopy for Control of Ethylene Oxide and Other Atmospheric Contaminants

这个第一阶段的小型企业技术转让（STTR）项目将展示一个全光谱拉曼分析仪原型，没有移动部件，包含一个小型的，新颖的拉曼光纤增强单元，可以快速测量环氧乙烷（EtO）和其他气体，低至ppm水平。拉曼的高度专一性最大限度地减少了复杂多组分系统中的信号串扰。光谱有窄峰，即使在有水分的情况下也容易观察到。为了使气相拉曼分析经济实用，我们将使用现成的激光二极管阵列作为光源。专有的外腔配置将线宽缩小到约10厘米-1。一个简单的光纤环路将循环激光能量提高约10倍，以获得足够高的激光能量，用于低浓度的气相检测。拉曼信号将由一个坚固的、光学速度快（f/1.4）的体积全息光谱仪收集，全光谱将使用一个灵敏的te冷却CCD阵列探测器进行检测。这种方法提供了一种简单，可靠的仪器，没有移动部件，减少了维护和良好的稳定性。EtO是一种无色气体，通常用于对温度敏感的医疗产品的灭菌，已被证明即使在低浓度（50 ppm）下也会对呼吸、皮肤和眼睛产生刺激。此外，长期暴露于EtO会给人类带来致突变性、生殖性和致癌性并发症。低于700ppm的EtO气味无法被检测到。需要一个气体传感器来快速监测EtO。与传统的红外、质谱或气相色谱方法相比，拟议的工作将展示拉曼仪器在美国大型工业过程分析仪市场上的易用性和应用范围。

9810572Benner This Phase I Small Business Technology Transfer (STTR) project will demonstrate that a full-spectrum Raman analyzer prototype with no moving parts that incorporates a small, novel Raman optical-fiber based enhancement cell can rapidly measure Ethylene Oxide (EtO) and other gases down to low ppm levels. Raman's high degree of specificity minimizes signal cross-talk in complex multicomponent systems. The spectra have narrow peaks which can be observed easily even in the presence of moisture. In order to make gas-phase Raman analysis affordable and practical we will use an off-the- shelf laser diode array as a light source. A proprietary external-cavity configuration will narrow the linewidth to around 10 cm-1. A simple, fiber-optic loop will enhance the circulating laser energy by approximately 10 X to obtain sufficiently high laser energy for gas-phase detection at low concentrations. The Raman signal will be collected with a rugged, optically fast (f/1.4) volume- holographic spectrograph, and the full spectrum will be detected using a sensitive TE-cooled CCD array detector. This approach offers a simple, reliable instrument with no moving parts, for reduced maintenance and good stability. EtO is a colorless gas commonly used for sterilization of medical products that are temperature sensitive, which has been demonstrated to be a respiratory, skin, and eye irritant even at low concentrations (50 ppm). In addition, long-term exposure to EtO presents mutagenic, reproductive, and carcinogenic complications to humans. Below 700 ppm the odor of EtO cannot be detected. A gas sensor is needed to rapidly monitor EtO. The proposed work will demonstrate the ease of use and breadth of application of Raman instrumentation compared to conventional IR, mass spectroscopy, or GC methodologies in a large U.S. market for industrial process analyzers.