Security

Security challenges require a thorough understanding of the entire detection process including initial sample acquisition, introduction into the analyzer, ionization techniques, and the detector itself. Excellims performs research and development in all of these areas.

For many trace detection applications, sample collection is as important in the detection process as anything that happens in the analyzer itself. For explosives detection applications, some of the most important commercial explosives have extremely low vapor pressures, but their use typically results in low levels of persistent residual traces. Conversely, for many of the most dangerous home-made explosives which are often used in terrorist IED's, the most likely sample available for detection is vapor. Since screeners looking for hidden explosives need to be able to detect all threats, sample collection systems need to collect all types of traces. In addition, the sample collection system should collect the maximum trace possible. Excellims research on sample collection is focused on methods that minimize dispersion or dilution of the available sample, and collect it with maximum efficiency in a form that can be introduced into the analyzer with minimum loss.

In addition to explosives detection, IMS instruments are widely used for detection of chemical agents and toxic industrial chemicals. There are four major criticisms of IMS based detectors; they are low resolution devices that cannot effectively discriminate between threats and interferents that cause false alarms; they cannot detect all of the threats that terrorists or enemy combatants might use; they are susceptible to masking interferents could cause false negatives; and they are not easily updated to detect new threats as they are encountered. Excellims IMS developments address all of these issues with the highest resolution drift tubes, novel ionization and sample introduction methods, and ultra-sensitive detectors. Excellims has patented a new Multi-dimensional IMS that allows ionization of threats in the presence of interferents, separates ions with high resolution in one drift tube, and then further separates them in an additional orthogonal drift tube. The result is an analyzer with a much wider range of detectable substances and very low false alarms.

Another promising innovation that may significantly improve IMS detectors has been demonstrated by Excellims and Washington State University for use in separating chiral molecules. Drift gas modification using Structure Selective Ion Molecule Interaction in the drift tube can shift the drift times of targeted analytes selectively to separate them from interferents that have similar drift times. This technique can reduce false positives and false negatives and extend the applicability of IMS to meet new detection challenges.

Excellims IMS-MS systems allow researchers and program managers to finally be fully confident of what it is that COTS IMS detectors are actually detecting. Our system has great flexibility and can be configured with different ionization sources and drift tube operating parameters to simulate the performance of commercial IMS instruments. By using the MS to determine the ion mass, peaks in the IMS may be confidently identified, both for target analytes and interferents.