The development of a new, lower cost method for trace explosives recovery from complex samples is presented using miniaturised, click-together and leak-free 3D-printed solid phase extraction (SPE) blocks. For the first time, a large selection of ten commercially available 3D printing materials were comprehensively evaluated for practical, flexible and multiplexed SPE using stereolithography (SLA), PolyJet and fused deposition modelling (FDM) technologies. Miniaturised single-piece, connectable and leak-free block housings inspired by Lego® were 3D-printed in a methacrylate-based resin, which was found to be most stable under different aqueous/organic solvent and pH conditions, using a cost-effective benchtop SLA printer. Using a tapered SPE bed format, frit-free packing of multiple different commercially available sorbent particles was also possible. Coupled SPE blocks were then shown to offer efficient analyte enrichment and a potentially new approach to improve the stability of recovered analytes in the field when stored on the sorbent, rather than in wet swabs. Performance was measured using liquid chromatography-high resolution mass spectrometry and was better, or similar, to commercially available coupled SPE cartridges, with respect to recovery, precision, matrix effects, linearity and range, for a selection of 13 peroxides, nitramines, nitrate esters and nitroaromatics. Mean % recoveries from dried blood, oil residue and soil matrices were 79 ± 24%, 71 ± 16% and 76 ± 24%, respectively. Excellent detection limits between 60 fg for 3,5-dinitroaniline to 154 pg for nitroglycerin were also achieved across all matrices. To our knowledge, this represents the first application of 3D printing to SPE of so many organic compounds in complex samples. Its introduction into this forensic method offered a low-cost, ‘on-demand’ solution for selective extraction of explosives, enhanced flexibility for multiplexing/design alteration and potential application at-scene.

使用小型化、卡合式且无泄漏的 3D 打印固相萃取 (SPE) 块开发了一种新的、成本较低的方法，用于从复杂样品中回收痕量爆炸物。首次使用立体光刻 (SLA)、PolyJet 和熔融沉积建模 (FDM) 技术对大量精选的 10 种商用 3D 打印材料进行了实用、灵活和多重 SPE 的综合评估。受 Lego® 启发，采用甲基丙烯酸酯树脂 3D 打印出微型单件、可连接且无泄漏的块状外壳，使用经济高效的台式树脂，发现这种树脂在不同的水/有机溶剂和 pH 条件下最稳定SLA 打印机。使用锥形 SPE 床形式，也可以无熔块填充多种不同的市售吸附剂颗粒。然后，耦合 SPE 模块被证明可以提供有效的分析物富集，并提供了一种潜在的新方法，可以提高现场回收的分析物在吸附剂上储存时的稳定性，而不是在湿拭子中。使用液相色谱-高分辨率质谱法测量性能，对于精选的 13 种过氧化物、硝胺、硝酸酯，在回收率、精度、基质效应、线性和范围方面，优于或类似于市售的耦合 SPE 小柱和硝基芳烃。干血、油渣和土壤基质的平均回收率分别为 79 ± 24%、71 ± 16% 和 76 ± 24%。所有基质均实现了 3,5-二硝基苯胺 60 fg 至硝酸甘油 154 pg 之间的出色检测限。据我们所知，这代表了 3D 打印首次应用于复杂样品中如此多有机化合物的 SPE。将其引入这种取证方法中，为选择性提取爆炸物提供了一种低成本、“按需”的解决方案，增强了多路复用/设计变更的灵活性以及潜在的现场应用。