Identification of Inorganic Improvised Explosive Devices Using Sequential Injection Capillary Electrophoresis and Contactless Conductivity Detection
Identification of Inorganic Improvised Explosive Devices Using Sequential Injection Capillary Electrophoresis and Contactless Conductivity Detection
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DOI：
10.1021/ac2020195
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发表时间：
2011-12-01
影响因子：
7.4
通讯作者：
Breadmore, Michael C.
中科院分区：
文献类型：
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作者：
Blanco, Gustavo A.;Nai, Yi H.;Breadmore, Michael C.
研制了一种简单的顺序注射毛细管电泳（SI-CE）电容耦合非接触电导检测器（（CD）-D-4），用于快速分离无机简易爆炸装置（IED）中的阴离子。四个最常见的爆炸示踪离子，硝酸盐，高氯酸盐，氯酸盐，和叠氮化物，和最常见的背景离子，氯化物，硫酸盐，硫氰酸盐，氟化物，磷酸盐，和碳酸盐，被选中进行调查。在溴化己二甲铵（HDMB）涂覆的毛细管中使用包含50 mM三（羟甲基）氨基甲烷、50 mM环己基-2-氨基乙磺酸（pH 8.9）和0.05%聚（乙烯亚胺）（PEI）的分离电解质，可以在90秒内部分分离所有10种离子。两种阳离子聚合物添加剂（PEI和HDMB）的组合是必要的，以实现具有足够稳定的电渗流（ECO 3）的足够的选择性，这对于仅一种聚合物是不可能的。通过对影响分离速度和进样时间的变量进行仔细优化，可将分离时间进一步缩短至55 s，同时保持足够的效率和分辨率。软件控制可实现高样品通量（60个样品/h），迁移时间的重复性非常高[240次进样的相对标准偏差（RSD）为0.63-2.07%]。分离速度并不影响灵敏度，对所考虑的所有爆炸残留物的检测极限为23至50 μ g·L-1，这比间接吸光度检测所达到的检测极限低10倍，比使用便携式台式仪器的（CD）-D-4所达到的检测极限低2倍。自动化、高样品通量、峰识别的高置信度和低检测限的组合使该方法成为快速识别无机IED残留物的理想方法。
A simple sequential injection capillary electrophoresis (SI-CE) instrument with capacitively coupled contactless conductivity detection ((CD)-D-4) has been developed for the rapid separation of anions relevant to the identification of inorganic improvised explosive devices (IEDs). Four of the most common explosive tracer ions, nitrate, perchlorate, chlorate, and azide, and the most common background ions, chloride, sulfate, thiocyanate, fluoride, phosphate, and carbonate, were chosen for investigation. Using a separation electrolyte comprising 50 mM tris(hydroxymethyl)aminomethane, 50 mM cyclohexyl-2-aminoethanesulfonic acid, pH 8.9 and 0.05% poly(ethyleneimine) (PEI) in a hexadimethrine bromide (HDMB)-coated capillary it was possible to partially separate all 10 ions within 90 s. The combination of two cationic polymer additives (PEI and HDMB) was necessary to achieve adequate selectivity with a sufficiently stable electroosmotic flow (EOF), which was not possible with only one polymer. Careful optimization of variables affecting the speed of separation and injection timing allowed a further reduction of separation time to 55 s while maintaining adequate efficiency and resolution. Software control makes high sample throughput possible (60 samples/h), with very high repeatability of migration times [0.63-2.07% relative standard deviation (RSD) for 240 injections]. The separation speed does not compromise sensitivity, with limits of detection ranging from 23 to 50 mu g.L-1 for all the explosive residues considered, which is 10 x lower than those achieved by indirect absorbance detection and 2 x lower than those achieved by (CD)-D-4 using portable benchtop instrumentation. The combination of automation, high sample throughput, high confidence of peak identification, and low limits of detection makes this methodology ideal for the rapid identification of inorganic IED residues.