Simultaneous colorimetric detection of metallic salts contained in low explosives residue using a microfluidic paper-based analytical device (μPAD)

A microfluidic paper-based analytical device (RAD) has been developed for the onsite determination of low explosives residues. The device is capable of simultaneous detection of a variety of metallic salts using colorimetric detection. The RAD was printed on chromatography paper with wax ink, allowing for the creation of a set of hydrophobic channels. Each channel contains a specific set of reagents that yields a color change upon interaction with a specific metal salt. The device is capable of performing six simultaneous tests, including the detection of metallic salts present in primer residues and pyrotechnic low explosive devices. Metals detected include lead, barium, antimony, iron, aluminum, zinc, and magnesium. Detection times were found to be less than 10 min and visual limits of detection ranged from 0.025 to 0.4 mu g of these metallic compounds. The resultant paper chip was then tested against various interferences and used to examine a number of different pyrotechnic compositions. This new device should prove useful in onsite detection of post-blast residues of pyrotechnics in the field due its portability and ease of use. (C) 2018 Published by Elsevier B.V.