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Documentation in support of your JEOL product.

Analysis of Advanced materials by FD-FI using AccuTOF GC (Part I)

Field Ionization (FI) is a soft ionization method that ionizes analytes by electron tunneling from analyte molecules to a solid surface (emitter) in a high electric field. The vaporized analyte molecules are introduced into the proximity of the emitter in order for ionization to occur. In this work, we analyzed functional monomers (building blocks for functional polymers) by GC/EI and GC/FI methods and then compared the resulting mass spectra.

Accurate Isotope Data is Essential for Determining Elemental Compositions

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.

A new method for pesticides identification: fast GC/time-of-flight mass spectrometry

Pesticides have been widely used all over the world. Although the use of pesticides is strictly regulated in many countries, laboratories still monitor their residues due to their toxicity and highly persistent nature. The most common method for pesticides identification is GC/MS with select ion monitoring (SIM). Since most of samples contain many different components, a long GC separation is generally needed when a low-resolution SIM MS is used. This is very time-consuming. Fast GC has been available for several years; however, the combination of fast GC with mass spectrometry had not been commercially available until high acquisition rate time-of-flight mass spectrometry was introduced. Here, we describe a new method by using fast GC/time-of-flight MS to identify 67 pesticides. The high resolution time-of-flight MS always yields high quality library searchable spectrums without compromising the sensitivity. The method is simple, fast, and reliable.

375 Pesticides x 5 Ions Exact Mass Database for Multi-residue Pesticide Analysis

The AccuTOF GCx has high sensitivity, high mass resolution, high mass accuracy, a wide dynamic range and a high speed acquisition rate, all simultaneously. Additionally, JEOL has developed a pesticides exact mass database that consists of 5 ions each for 375 different compounds which means that there are 1,875 total exact masses for multi-residue pesticide analysis. And because the TOF continuously collects the complete m/z region for each mass spectrum, we do not need to setup any SIM or SRM conditions, as is done for QMS and QqQMS systems. Therefore, the TOFMS can be used for both quantitative and qualitative analysis, simultaneously. In this application note, we show a portion of the pesticide database and the advantages of the GC/HR-TOFMS system for the multi-residue pesticide analysis.

Other Resources

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Media

Corona - Glow Discharge (DART Ion Source)

February 22, 2020
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