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Documentation in support of your JEOL product.

DART Analysis of Aspirin: Correcting a Misapprehension

In a recently published comparison of the ambient ionization techniques direct analysis in real time (DART™) and DESI, it was reported that a protonated molecule was not observed for DART, whereas the protonated molecule could be observed for DESI and DAPCI. This is an incorrect observation, resulting from the use of different experimental conditions for DART than were used for the other two techniques. Mass spectra of aspirin measured on a JEOL AccuTOF-DART™ mass spectrometer under the correct operating conditions are shown here. All assignments for the mass spectral peaks were confirmed by exact mass measurements.

Clandestine Methamphetamine Labs: Rapid Impurity Profiling by AccuTOF-DART™

Methamphetamine is a Schedule II Controlled Substance that is illegally manufactured in clandestine labs. There are several common synthetic pathways in use. For this study, methamphetamine was synthesized from phenyl-2-propanone by the (1) Leukart synthesis or (2) Reductive Amination, or from ephedrine or pseudoephedrine by the (3) Nagai, (4) Birch, and (5) Edme syntheses. Each of these reaction sequences resulted in unique impurity profiles1-3 that can be used by law enforcement to track the activities of clan labs, distribution networks, and trafficking patterns. The AccuTOF-DART was used to examine the starting materials, reaction mixtures, and final products from each reaction scheme.

Chemical Reaction Monitoring with the AccuTOF-DART™ Mass Spectrometer

DART provides a convenient means for monitoring the progress of chemical reactions. Reactants, intermediates, products and byproducts can be detected by simply dipping a glass rod into the reaction pot and then placing the rod in front of the DART ion source. The AccuTOF's ability to measure accurate masses and isotopic abundances makes it possible to confirm or identify the elemental compositions of peaks in the mass spectra. Here we show the use of AccuTOF-DART to monitor the acetylation of 1,2-hexanediol as a function of time.

Analysis of stobilurins in wheat grains using DART-TOFMS

Strobilurins, systemic pesticides originated from natural fungicidal derivatives, play an important role in control of various plant pathogens. Because of their unique protective properties, significant yield enhancements and longer retention of green leaf tissue, strobilurins have been widely used in agriculture since their introduction on the market in 1992. As other pesticides, these compounds are involved in control and monitoring surveys undertaken by regulation authorities.

AccuTOF-DART analysis of motor oils

DART can characterize additives in lubricating oils directly without sample preparation. The additives generally produce a strong signal without interference from the base oil. However, complementary information about nonpolar components of the base oil can be obtained by O2 ─• attachment chemical ionization, a simple analysis that can be easily and rapidly carried out with changing any hardware on the AccuTOF-DART mass spectrometer system.

Analysis of highly polar compound (ionic liquid) by DART

Ionic liquids have drawn much attention from various engineering fields, such as tribology, because of their unique properties of electrical conductivity, extremely low vapor pressure, low viscosity, low combustibility, etc. The sample was analyzed by dipping a glass rod to the sample and presented it directly to the DART™ ion source.

Analysis of duct tapes by thermal desorption and pyrolysis mass spectrometry and X-ray-fluorescence spectroscopy

The identification of pressure-sensitive tapes such as duct tape and electrical tape is an important forensic application. Here we show the application of thermal desorption and pyrolysis combined with Direct Analysis in Real Time (DART) mass spectrometry to distinguish between manufacturers and brands of duct tapes. X-ray fluorescence (XRF) provides complementary information about the atomic composition of the different tapes.

Other Resources

The following resources are available for the JEOL Analytical Instruments:

Media

Corona - Glow Discharge (DART Ion Source)

February 22, 2020
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