Smith Philip A, Lepage Carmela Jackson, Harrer Kristin L, Brochu Paul J
Naval Medical Center San Diego, Directorate for Public Health, San Diego, California 92126, USA.
J Occup Environ Hyg. 2007 Oct;4(10):729-38. doi: 10.1080/15459620701547233.
Suitable detectors are needed to support survey needs of incident responders and health care personnel who may receive patients from an incident with exposures to hazardous chemicals. In the health care setting, such a detector would avoid cross-contamination to workers, patients, and to the treatment facility and associated equipment. An ideal survey detector would be sensitive, hand-held, capable of extended battery operation, and would provide a nearly immediate detector response on exposure to a broad range of high-concern chemicals. For responders, important capabilities would include quantitative measurement of gas/vapor contamination, and for both response and health care settings, qualitative detection of contaminated people and objects. In this study, the operating characteristics of photoionization detector (PID) instruments were examined using O-isopropyl methylphosphonofluoridate (sarin) in a laboratory setting. Instrument response factors were calculated for quantitation of airborne sarin, and speed of detector response and recovery were examined with point-contaminated cloth material. By sampling a range of sarin-contaminated air, calculated isobutylene unit response factors for high-and moderate-sensitivity commercial PID instrument types were 11.3 and 14.0 (dry air) and 20.1 and 44.4 (50% relative humidity), respectively. Response of the PID systems was highly correlated to concentration sampled, with R(2) values greater than or equal to 0.997 for all combinations of PID detector type and humidity. While not sensitive enough to warn the unprotected public against a chemical with an extremely low "safe" exposure concentration, quantitation with available PID instruments could be useful to quickly prioritize corrective measures for a PID-detectable chemical. Qualitative survey characteristics were examined for the more sensitive PID tested using a piece of cloth material contaminated by a 1.0 micro L droplet of liquid sarin. Rapid response and recovery times (seconds) were observed when the sampling inlet was moved close to and away from the point of contamination. Within the health care setting, hand-held PID instruments could fill an important and currently unmet need as a point source detector for liquid contamination from extremely dangerous chemicals to help identify contaminated surfaces and limit secondary contamination and exposures.
需要合适的探测器来满足事故应急人员和医护人员的检测需求，这些人员可能接收来自接触危险化学品事故的患者。在医疗环境中，这样的探测器应避免对工作人员、患者以及治疗设施和相关设备造成交叉污染。理想的检测探测器应灵敏、手持式、具备长时间电池续航能力，并且在接触多种高关注度化学品时能几乎立即给出探测器响应。对于应急人员而言，重要的功能应包括对气体/蒸汽污染进行定量测量，而对于应急和医疗环境来说，还应具备对受污染人员和物体进行定性检测的能力。在本研究中，在实验室环境下使用氟磷酸异丙酯（沙林）对光离子化探测器（PID）仪器的操作特性进行了检测。计算了仪器响应因子以对空气中的沙林进行定量分析，并使用点染污的布料检测了探测器的响应速度和恢复速度。通过对一系列受沙林污染的空气进行采样，计算得出高灵敏度和中灵敏度商用PID仪器类型的异丁烯单位响应因子在干燥空气中分别为11.3和14.0，在50%相对湿度下分别为20.1和44.4。PID系统的响应与采样浓度高度相关，对于PID探测器类型和湿度的所有组合，R²值均大于或等于0.997。虽然对于“安全”暴露浓度极低的化学品，现有PID仪器不够灵敏，无法向未受保护的公众发出警告，但使用现有PID仪器进行定量分析对于快速确定针对PID可检测化学品的纠正措施优先级可能会很有用。使用一块被1.0微升液体沙林液滴污染的布料，对测试的更灵敏的PID的定性检测特性进行了检测。当采样入口靠近和远离污染点时，观察到快速的响应和恢复时间（数秒）。在医疗环境中，手持式PID仪器作为一种点源探测器，可用于检测极其危险化学品造成的液体污染，有助于识别受污染表面并限制二次污染和暴露，能满足一项重要且目前尚未得到满足的需求。
