Analytical Instrument Documents

DART mass spectrometry commonly uses helium as the DART gas. With the looming helium shortage, other gases are being evaluated for DART.

Notebook containing various articles and application notes pertaining to the AccuTOF DART.

Some of the characteristic compounds that are responsible for the bright colors of autumn leaves are readily detected by using various ambient ionization methods with the AccuTOF-DART mass spectrometer system.

JEOL offers numerous analytical tools to support both "food safety & security" as well as various evaluations of primary, secondary and tertiary functions of foodstuffs which are useful for a wide range of users associated with this field. This Foodnote introduces the features of each of the instruments and actual analysis examples, and is designed for researchers and engineers who are considering purchases of instruments. This brochure also presents comprehensive evaluations and analysis solutions that can be achieved with combinations of multiple instruments.

The chemical composition of herbs and spices can vary dramatically between different species and different growing conditions. Herbs grown under different conditions that have different essential oil compositions are referred to as chemotypes. Basil is an herb that has widely varying chemotypes. The difference between basil leaves from two different sources was easily observed by using DART. A leaf from a basil plant purchased at a grocery store was compared with a leaf from a Vietnamese restaurant. A small particle from each leaf was analyzed placed in front of the DART source. Mass spectra were obtained within seconds. Elemental compositions were confirmed by exact masses and accurate isotopic abundance measurements.

Mass Spectrometry (MS) is one of the fastest-growing areas in analytical instrumentation. The use of mass spectrometry in support of synthetic, organic, and pharmaceutical chemistry is well established. Mass spectrometry is also used in materials science, environmental research, and forensic chemistry. It has also evolved into one of the core methods used in biotechnology. However, currently available ion sources place extreme restrictions on the speed and convenience of sample analysis by mass spectrometry. Here we report a method for using mass spectrometry to instantaneously analyze gases, liquids, and solids in open air at ground potential under ambient conditions. Traditional ion sources used in mass spectrometry require the introduction of samples into a high vacuum system.

JEOL introduced the DART ion source in 2005, and the technology quickly gained recognition, winning both the Pittcon Editor’s Gold Award and the R&D 100 Award. Since that time nearly 400 papers have been published by chemists using the AccuTOF-DART. The introduction of DART made it possible for the first time to carry out atmospheric pressure ionization for analysis of samples in open air.

Since 1949, the JEOL legacy has been one of outstanding innovation in developing instruments used to advance scientific research and technology. JEOL has over 60 years of expertise in the field of electron microscopy, more than 50 years in mass spectrometry. In this applications note, we performed an analysis of a Gold Star Mothers Postage Stamp by using three JEOL instruments. We used the JSM-IT300LV which the latest addition to JEOL‘s popular series of analytical low vacuum SEM, , the JMS-T100LP “AccuTOF- DART” the first commercially available ambient ionization mass spectrometer, and the JMS-S3000 “SpiralTOF” which has highest mass-resolution and mass accuracy of all commercially available MALDI-TOFMS systems. We can therefore correlate analyses from various analytical techniques on the same sample.

Elemental compositions are commonly determined from high-resolution mass spectra and accurate mass measurements. Given a measured mass (m/z) and a range of elements that can be present, software calculates the exact mass for each combination of elements and reports all elemental combinations that match the measured mass within a specified error tolerance. Improving the mass accuracy reduces the number of elemental compositions, but mass accuracy alone may not be sufficient to determine the correct elemental composition for an unknown sample. JEOL AccuTOF™ mass spectrometers (the AccuTOF™-DART®, the AccuTOF™-GCX and the AccuTOF™-GCX Plus) are capable of accurate isotope measurements that can be used to determine elemental compositions from high-resolution mass spectra. Matching the measured abundances and exact masses for isotope peaks can be more effective than mass accuracy alone.

Solid phase microextraction (SPME) is a well established sampling technique that is often used to isolate volatile organic components in gaseous mixtures. Once the compounds have been collected, the SPME fibers are typically placed into a heated GC inlet which thermally desorbs these components into a GC-MS system for analysis. Normally, this analysis can take between 10 and 30 minutes to complete depending on the complexity of the samples. In this work, the Direct Analysis in Real Time (DART™) heated gas stream is used to desorb and directly introduce a SPME sample into a high-resolution mass spectrometer. This methodology produces comparable information to the traditional GC-MS technique but streamlines the results into only a few seconds of analysis time.