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
Metadata
Item Type:
Article (Published)
Refereed:
Yes
Additional Information:
Article number: 461506.
Uncontrolled Keywords:
3D printing; Solid phase extraction; Forensic science; Complex matrices;
High resolution mass spectrometry