EXCELLIMS CORP

A rapid on-site analytical method is developed for screening lidocaine and four other types of prohibited ingredients in cosmetics using thermal desorption-corona discharge ionization together with ion mobility spectrometry. Performing no pretreatment, we dropped or sprayed cosmetic samples onto a Nomex sampling swab. The sampler was placed into a compartment for thermal desorption and corona discharge ionization; then, ion mobility spectrometry analysis was performed. The limits of detection (LODs) for the five analytes ranged from 10 to 50 ng. The instrumental analysis time for a single run was less than 20 ms, and the total sample analysis period was within 1 min. The proposed method is simple, fast, and has low cost, and could be used as an analytical tool for rapid on-site screening of prohibited ingredients in cosmetics.

The detailed chemical characterization of homemade explosives (HMEs) and other chemicals that can mimic or mask the presence of explosives is important for understanding and improving the performance of commercial instrumentation used for explosive detection. To that end, an atmospheric-pressure drift tube ion mobility spectrometry (IMS) instrument has been successfully coupled to a commercial tandem mass spectrometry (MS) system. The tandem MS system is comprised of a linear ion trap and a high resolution Orbitrap analyzer. This IMS-MS combination allows extensive characterization of threat chemical compounds, including HMEs, and complex real-world background chemicals that can interfere with detection. Here, the composition of ion species originating from a specific HME, erythritol tetranitrate, has been elucidated using accurate mass measurements, isotopic ratios, and tandem MS. Gated IMS-MS and high-resolution MS have been used to identify minor impurities that can be indicative of the HME source and/or synthesis route. Comparison between data obtained on the IMS/MS system and on commercial stand-alone IMS instruments used as explosive trace detectors (ETDs) has also been performed. Such analysis allows better signature assignments of threat compounds, modified detection algorithms, and improved overall ETD performance. Graphical Abstract ᅟ.

The overall objective of this project was to develop an anal. method that uses structure selective ion mol. interactions (SSIMI) in ion mobility spectrometry (IMS) to shift the mobility of a targeted analyte through the addition of a gas phase modifier to the buffer gas.IMS is a sensitive, rapid method for the detection of harmful chems.; however false alarm responses do occur and a reduction in their frequency decrease both the cost and time required for detection.The study reported here probed the effects of buffer gas modifiers on the mobilities of chem. warfare agent simulants (CWAs), toxic industrial chems. (TICs) and a known interference (Butyl Carbitol) found in fire extinguishing agents.The major finding of this research was that a modifier with a proton affinity similar to, but not greater than, the target analyte produced the greatest changes in mobilities due to the formation of an ion cluster between the neutral modifier and target analyte ion.Mass spectrometry was used to confirm the formation of ion-neutral clusters that caused the target ion to shift its mobility.While a number of modifiers were screened, acetonitrile and isobutyronitrile have sufficiently selective SSIMI with the target compoundFor example, in the presence of acetonitrile modifier, the protonated response ion of the CWA simulant DMMP, [DMMP]H⁺, had a mobility shift of 10.8 %, but the mobility was unchanged for the interferent, Butyl Carbitol.The mobility of the simulant DMMP decreased with the introduction of modifiers, while the mobility of the interference did not change, demonstrating the potential of the SSIMI technique for reducing false alarm rates.