Laser-based spectrometer for real-time monitoring of VOCs at Superfund sites

描述(由申请人提供)：受污染的地下水羽流排放的有毒挥发性有机化合物(VOC)对全国各地的工业场所构成重大健康风险，因此在超级基金地点进行VOC监测是一种特殊的需求。现场对有毒VOCs的准确、实时监测对于评估补救工作的成功、评估人类健康风险以及开发可靠的暴露模型至关重要，这些模型适当地考虑了混杂因素，如时间暴露变化和特定人群的药代动力学。不幸的是，简单、快速和准确的VOC监测是一个持续的挑战，现有的技术成本高、劳动密集型、速度慢，并且无法表征反应性气体(如丙烯醛、臭氧等)。在这个小型企业创新研究(SBIR)项目中，洛斯加托斯研究公司(LGR)将开发一种自主仪器，用于实时监测环境空气中VOCs的百万分比(Ppb)水平，而不需要大量的消耗品。LGR的VOC检测器将显著提高Superfund站点的数据质量，允许更快速、更频繁的测量，而无需劳动密集型样本收集和运输，同时保持与替代技术的成本竞争力。VOC分析仪将使用LGR的中红外(MIR)非相干腔衰荡光谱(ICRDS)技术，该技术利用宽可调的外腔量子级联激光器(8.3-12.55m)和化学计量拟合算法来直接测量和分析环境空气中多个VOCs造成的光吸收。在该项目的第一阶段，LGR将改进现有的MIR iCRDS分析仪，以包括更大的波长范围和改进的光学系统。我们将验证该仪器准确识别和量化各种环境空气成分中VOCs的能力，包括VOC到VOC测量串扰的分析。此外，LGR将在加利福尼亚州山景城的Superfund站点部署该原型，以记录、分析和报告环境空气中的VOC浓度。在项目结束时，LGR将展示使用MIR iCRDS检测超级基金地点的VOCs，作为表征有毒气体入侵对人类健康风险的一种更好的方法。 与公共卫生相关：工业污染物对地下水的污染对在受污染场地上生活和工作的个人的健康构成重大风险。测量到达室内空气(工作场所、办公室和家庭)的污染物浓度是了解并最终将受污染的地下水对人类健康的危害降至最低的关键第一步(特别是在超级基金站点)。洛斯加托斯研究公司提议的挥发性有机污染物测量仪器将极大地改进现有的监测技术，提高数据速率以表征瞬时暴露，准确测量活性物质，并消除与样本采集相关的劳动力成本。

DESCRIPTION (provided by applicant): Toxic volatile organic compounds (VOCs) emitted from contaminated groundwater plumes represent a significant health risk at industrial sites throughout the nation and a specific need exists for VOC monitoring at Superfund sites. Accurate, real-time monitoring of toxic VOCs on site is critical to evaluating the success of remediation efforts, assessing human health risks, and developing robust exposure models that properly account for confounding factors such as temporal exposure variation and population-specific pharmacokinetics. Unfortunately, simple, rapid, and accurate VOC monitoring is an ongoing challenge, and available technology is costly, labor intensive, slow, and unable to characterize reactive gases (e.g. acrolein, ozone, etc.). In this Small Business Innovative Research (SBIR) project, Los Gatos Research (LGR) will develop an autonomous instrument for the real-time monitoring of sub-parts per billion (ppb) levels of VOCs in ambient air without requiring extensive consumables. LGR's VOC detector will significantly improve data quality at Superfund sites by allowing for more rapid and frequent measurements without labor-intensive collection and transport of sample traps, while remaining cost competitive with alternative technologies. The VOC analyzer will use LGR's mid infrared (MIR) incoherent cavity ringdown spectroscopy (iCRDS) technology, which utilizes a broadly tunable external cavity quantum cascade lasers (8.3 - 12.5 5m) and chemometric fitting algorithm to directly measure and analyze optical absorption due to multiple VOCs in ambient air. During Phase I of this project, LGR will refine an existing MIR iCRDS analyzer to include a larger wavelength range and improved optics. We will verify the instrument's ability to accurately identify and quantify VOCs in a variety of ambient air compositions, including an analysis of VOC-to-VOC measurement crosstalk. Additionally, LGR will deploy the prototype at a Superfund site in Mountain View, California to record, analyze, and report VOC concentrations in ambient air. At the conclusion of the project, LGR will have demonstrated the use of MIR iCRDS for the detection of VOCs at Superfund sites as a superior method of characterizing the risks to human health from toxic vapor intrusion. PUBLIC HEALTH RELEVANCE: The contamination of groundwater by industrial pollutants poses a significant risk to the health of individuals living and working above tainted sites. Measuring the concentration of pollutants that reach indoor air (worksites, offices and homes) is a critical first step to understanding and ultimately minimizing the human health hazards of contaminated ground water (especially at Superfund sites). Los Gatos Research's proposed instrument for measuring volatile organic pollutants will greatly improve on existing monitoring technology by increasing the data rate to characterize transient exposure, accurately measuring reactive species, and eliminating labor costs associated with sample collection.