Analytical Instrument Documents

The FastGC method is a very useful technique for doing rapid GC analyses that result in extremely narrow chromatographic peaks over a shorter time period than traditional GC analyses. Additionally, time-of-flight mass spectrometers (TOFMS) are capable of very fast data acquisition in comparison with other types of mass spectrometers so they are well suited as the detector for the FastGC technique. Furthermore, when the TOFMS is capable of high resolution measurements, the resulting mass spectra contain accurate mass information that can be used to calculate the elemental compositions for each observed m/z. In this application note, we describe the quanitative analysis of pyrazole pesticides (Fipronil, Ethiprole, Pyraflufen ethyl and Tebfenpyrad) on tea leaves by FastGC/HRTOFMS. Additionally, we confirm that a rapid analysis with high sensitivity is easy to perform and very useful for fast screening.

The FastGC method is a very useful technique for doing rapid GC analyses that result in extremely narrow chromatographic peaks over a shorter time period than traditional GC analyses. Additionally, time-of-flight mass spectrometers (TOFMS) are capable of very fast data acquisition in comparison with other types of mass spectrometers so they are well suited as the detector for the FastGC technique. Furthermore, when the TOFMS is capable of high resolution measurements, the resulting mass spectra contain accurate mass information that can be used to calculate the elemental compositions for each observed m/z. In this application note, we describe the qualitative analysis of pyrazole pesticides (Fipronil, Ethiprole, Pyraflufen ethyl and Tebfenpyrad) on tea leaves by FastGC/HRTOFMS. Additionally, we confirm that a rapid analysis with high sensitivity is easy to perform and very useful for fast screening.

Comprehensive two-dimensional gas chromatography (GC×GC) is a kind of continuous heart-cut GC system. Two different types of columns are connected via a modulator in the same GC oven. By using the two columns together, this technique provides very high separation capabilities when compared to one- dimensional GC analysis. However, GC×GC systems require a fast data acquisition detection system in order to record the very narrow time width peaks observed in the GC chromatograms. The JEOL AccuTOF-GC is a time-of-flight mass spectrometer (TOFMS) that fully meets this high speed data acquisition requirement at 25Hz (0.04sec) so it can be successfully used as the detection system in combination with GC×GC. In this work, the AccuTOF-GC was used for the qualitative analysis of polycyclic aromatic hydrocarbons in kerosene by GC×GC -TOFMS.

Comprehensive two-dimensional gas chromatography (GC×GC) is a kind of continuous heart-cut GC system. Two different types of columns are connected via a modulator in the same GC oven. By using the two columns together, this technique provides very high separation capabilities when compared to one-dimensional GC analysis. However, GC×GC systems require a fast data acquisition detection system in order to record the very narrow time width peaks observed in the GC chromatograms. The JEOL AccuTOF-GC is a time-of-flight mass spectrometer (TOFMS) that fully meets this high speed data acquisition requirement at 25Hz (0.04sec) so it can be successfully used as the detection system in combination with GC×GC. In this work, the AccuTOF-GC was used to analyze kerosene and diesel oil samples by GC×GC -TOFMS.

Field Desorption (FD) and Field Ionization (FI) are both techniques that ionize analytes by electron tunneling from the analyte molecules to a solid surface (emitter) in a high electric field. In the case of FD, the sample is applied directly onto the emitter and heated by applying an electric current through the emitter for desorption and ionization. In the case of FI, vaporized analyte molecules are introduced into the proximity of the emitter. Both FI and FD are soft ionization methods that generally yield intact molecular ions and, in most cases, produce very few fragment ions. Generally, these two techniques are used to ionize analytes that are easy to fragment and do not generally produce molecular ions during electron ionization (EI), such as hydrocarbons in crude oil.

Field Desorption (FD) and Field Ionization (FI) are both techniques that ionize analytes by electron tunneling from the analyte molecules to a solid surface (emitter) in a high electric field. In the case of FD, the sample is applied directly onto the emitter and heated by applying an electric current through the emitter for desorption and ionization. In the case of FI, vaporized analyte molecules are introduced into the proximity of the emitter. Both FI and FD are soft ionization methods that generally yield intact molecular ions and, in most cases, produce very few fragment ions. Generally, these two techniques are used to ionize analytes that are easy to fragment and do not generally produce molecular ions during electron ionization (EI), such as hydrocarbons in crude oil.

The high boiling point compounds cholesterol and Irganox® 1010, an anti-oxidant additive for polymers, were analyzed by GC/MS. The analyses were performed using electron ionization (EI) and field ionization (FI), which is a soft ionization method, to show the difference in mass spectral patterns that result from these two ionization techniques.

Transformer oil containing no PCBs was diluted 10,000 times, and then this solution was spiked with a mixture of commercially available PCBs (KC-500). The resulting sample was analyzed by using the JEOL AccuTOF-GC with FastGC/MS conditions. Afterwards, the data was examined by varying the mass range window (called "window width") used for the PCB reconstructed ion chromatogram (RIC) to determine if the effect of the background impurities can be eliminated so that the analyte peaks are easily observed in the resulting data.

This report shows the analyses of the phenolic polymer antioxidants shown in Fig. 1. These samples were analyzed by using the AccuTOF-GCV with both direct insertion probe（DIP）electron ionization (EI) and field desorption (FD).

Three polydimethylsiloxane compounds: octamethylcyclotetrasiloxane (sample 1), decamethylcyclopentasiloxane (sample 2) and octa(dimethylsiloxy)silsesquioxane (sample 3), were analyzed using a GC/TOFMS. The first two samples are relatively small molecules with molecular weights of 296 and 370, respectively, so they were introduced into the system through the mass reference sample inlet (reservoir). Sample 3 is a much bigger molecule with a molecular weight of 1,016 that could not be introduced through the reservoir. As a result, this sample was introduced by injecting it into the GC.