Institute for Sustainable Industries and Liveable Cities (ISILC), Victoria University, Werribee, Victoria, 3030, Australia.
Institute for Sustainable Industries and Liveable Cities (ISILC), Victoria University, Werribee, Victoria, 3030, Australia.
Anal Chim Acta. 2023 May 15;1255:341156. doi: 10.1016/j.aca.2023.341156. Epub 2023 Mar 28.
Organic peroxide explosives (OPEs) are unstable, non-military, contemporary security threats often found in improvised explosive devices. Chemiluminescence (CL) can be used to detect OPEs, via radical formation consisting of peroxide moieties (-O-O-) under acidic conditions. However, selectivity for specific OPEs is hampered by the ubiquitous background of HO. Herein, we report the differentiation of hexamethylene triperoxide diamine (HMTD), triacetone triperoxide (TATP), and methyl ethyl ketone peroxide (MEKP) by specific flow injection analysis-CL (FIA-CL) signal profiles, after HSO treatment. The radical degradation pathway of each structure, and its corresponding FIA-CL profile, was explored using mass spectrometry to reveal the rapid loss of -O-O- from TATP and HMTD structures, while MEKP formed CL signal-sustaining oligomers, as opposed to the immediate attenuation of HO. The CL response for OPEs in an aqueous media, measured via the described FIA-CL method, enabled ultra-trace limits of detection down to 0.40 μM for MEKP, 0.43 μM for HMTD, and 0.40 μM for TATP (combined linear range 1-83 μM with 95% confidence limit, n = 12). Expanded uncertainties of measurement (UM) of MEKP = ±0.98, HMTD = ±1.03, and TATP = ±1.1 (UM included probabilities of false positive and false negative as well as standard deviations of % recoveries and limit of detections of OPEs). Direct aqueous sample introduction via FIA-CL thus offers the prospect of rapid and selective screening of OPEs in security-heightened settings (e.g., airports), averting false positives from more ubiquitous HO.
过氧化物炸药（OPEs）是不稳定的、非军用的、现代安全威胁，通常存在于简易爆炸装置中。化学发光（CL）可用于检测 OPEs，通过在酸性条件下过氧部分（-O-O-）形成自由基。然而，由于 HO 的普遍存在，对特定 OPEs 的选择性受到阻碍。在此，我们报告了六亚甲基三过氧化物二胺（HMTD）、三丙酮三过氧化物（TATP）和甲乙酮过氧化物（MEKP）在 HSO 处理后通过特定的流动注射分析-CL（FIA-CL）信号谱的差异。使用质谱探索了每种结构的自由基降解途径及其相应的 FIA-CL 谱，揭示了 TATP 和 HMTD 结构中-O-O-的快速损失，而 MEKP 形成了 CL 信号持续的低聚物，而不是 HO 的立即衰减。通过所描述的 FIA-CL 方法在水介质中对 OPEs 的 CL 响应，使 MEKP 的超痕量检测限低至 0.40 μM，HMTD 为 0.43 μM，TATP 为 0.40 μM（结合线性范围为 1-83 μM，置信限为 95%，n=12）。MEKP 的测量扩展不确定度（UM）=±0.98，HMTD=±1.03，TATP=±1.1（UM 包括假阳性和假阴性的概率以及 OPEs 的回收率标准偏差和检测限）。通过 FIA-CL 直接进行水相样品引入，从而有望在安全要求较高的环境（例如机场）中快速选择性筛选 OPEs，避免 HO 带来的假阳性。
