Demonstrating the Use of Non-targeted Analysis for Identification of Unknown Chemicals in Rapid Response Scenarios

Several
thousand intentional and unintentional chemical releases
occur annually in the U.S., with the contents of almost 30% being
of unknown composition. When targeted methods are unable to identify
the chemicals present, alternative approaches, including non-targeted
analysis (NTA) methods, can be used to identify unknown analytes.
With new and efficient data processing workflows, it is becoming possible
to achieve confident chemical identifications via NTA in a timescale useful for rapid response (typically 24–72
h after sample receipt). To demonstrate the potential usefulness of
NTA in rapid response situations, we have designed three mock scenarios
that mimic real-world events, including a chemical warfare agent attack,
the contamination of a home with illicit drugs, and an accidental
industrial spill. Using a novel, focused NTA method that utilizes
both existing and new data processing/analysis methods, we have identified
the most important chemicals of interest in each of these designed
mock scenarios in a rapid manner, correctly assigning structures to
more than half of the 17 total features investigated. We have also
identified four metrics (speed, confidence, hazard information, and
transferability) that successful rapid response analytical methods
should address and have discussed our performance for each metric.
The results reveal the usefulness of NTA in rapid response scenarios,
especially when unknown stressors need timely and confident identification.

美国每年会发生数千起有意或无意的化学品泄漏事件，其中近30%的泄漏物成分未知。当靶向分析方法无法识别检出的化学品时，可采用包括非靶向分析（non-targeted analysis, NTA）在内的替代方法来鉴定未知分析物。借助新型高效的数据处理工作流，如今已可通过非靶向分析在适用于应急响应的时间窗内（通常为接收样品后的24~72小时）实现可靠的化学品鉴定。为验证非靶向分析在应急响应场景中的应用潜力，本研究设计了三个模拟真实事件的场景：化学战剂袭击、居家场所受违禁毒品污染，以及意外工业化学品泄漏。本研究采用一种整合了现有与新型数据处理分析方法的新型靶向性非靶向分析方法，快速鉴定出各模拟场景中的核心目标化学品，对全部17个待分析特征中超过一半的特征成功确证了分子结构。此外，本研究还明确了一套成功的应急响应分析方法需满足的四项评价指标：速度、可靠性、危害信息获取能力与可迁移性，并针对每项指标评估了本研究的表现。研究结果证实了非靶向分析在应急响应场景中的应用价值，尤其适用于需要快速、可靠鉴定未知胁迫源的情形。