TY - JOUR
T1 - Bomb swab
T2 - Can trace explosive particle sampling and detection be improved?
AU - Fisher, Danny
AU - Zach, Raya
AU - Matana, Yossef
AU - Elia, Paz
AU - Shustack, Shiran
AU - Sharon, Yarden
AU - Zeiri, Yehuda
N1 - Funding Information:
This material is based upon work partially supported by the U.S. Department of Homeland Security, Science and Technology Directorate, Office of University Programs, under Grant 2013-ST-061-ED0001. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security.
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/11/1
Y1 - 2017/11/1
N2 - The marked increase in international terror in recent years requires the development of highly efficient methods to detect trace amounts of explosives at airports, border crossings and check points. The preferred analytical method worldwide is the ion mobility spectrometry (IMS) that is capable of detecting most explosives at the nano-gram level. Sample collection for the IMS analysis is based on swabbing of a passenger's belongings to collect possible explosive residues. The present study examines a wide range of issues related to swab-based particle collection and analysis, in the hope of gaining deeper understanding into this technique that will serve to improve the detection process. The adhesion of explosive particles to three typical materials, plastic, metal and glass, were measured using atomic force microscopy (AFM). We found that a strong contribution of capillary forces to adhesion on glass and metal surfaces renders these substrates more promising materials upon which to find and collect explosive residues. The adhesion of explosives to different swipe materials was also examined. Here we found that Muslin, Nomex® and polyamide membrane surfaces are the most promising materials for use as swipes. Subsequently, the efficiency of multiple swipe use – for collecting explosive residues from a glass surface using Muslin, Nomex® and Teflon™ swipes – was examined. The study suggests that swipes used in about 5–10 “sampling and analysis cycles” have higher efficiency as compared to new unused swipes. The reason for this behavior was found to be related to the increased roughness of the swipe surface following a few swab measurements. Lastly, GC-MS analysis was employed to examine the nature of contaminants collected by the three types of swipe. The relative amounts of different contaminants are reported. The existence and interference of these contaminants have to be considered in relation to the detection efficiency of the various explosives by the IMS.
AB - The marked increase in international terror in recent years requires the development of highly efficient methods to detect trace amounts of explosives at airports, border crossings and check points. The preferred analytical method worldwide is the ion mobility spectrometry (IMS) that is capable of detecting most explosives at the nano-gram level. Sample collection for the IMS analysis is based on swabbing of a passenger's belongings to collect possible explosive residues. The present study examines a wide range of issues related to swab-based particle collection and analysis, in the hope of gaining deeper understanding into this technique that will serve to improve the detection process. The adhesion of explosive particles to three typical materials, plastic, metal and glass, were measured using atomic force microscopy (AFM). We found that a strong contribution of capillary forces to adhesion on glass and metal surfaces renders these substrates more promising materials upon which to find and collect explosive residues. The adhesion of explosives to different swipe materials was also examined. Here we found that Muslin, Nomex® and polyamide membrane surfaces are the most promising materials for use as swipes. Subsequently, the efficiency of multiple swipe use – for collecting explosive residues from a glass surface using Muslin, Nomex® and Teflon™ swipes – was examined. The study suggests that swipes used in about 5–10 “sampling and analysis cycles” have higher efficiency as compared to new unused swipes. The reason for this behavior was found to be related to the increased roughness of the swipe surface following a few swab measurements. Lastly, GC-MS analysis was employed to examine the nature of contaminants collected by the three types of swipe. The relative amounts of different contaminants are reported. The existence and interference of these contaminants have to be considered in relation to the detection efficiency of the various explosives by the IMS.
KW - AFM
KW - Adhesion force
KW - IMS
KW - Particle sampling
KW - Swipe material
KW - Trace explosives detection
UR - http://www.scopus.com/inward/record.url?scp=85020049042&partnerID=8YFLogxK
U2 - 10.1016/j.talanta.2017.05.085
DO - 10.1016/j.talanta.2017.05.085
M3 - Article
C2 - 28738664
AN - SCOPUS:85020049042
SN - 0039-9140
VL - 174
SP - 92
EP - 99
JO - Talanta
JF - Talanta
ER -