First Published: JEOL USA September 2018.
Introduction
Advances in mass spectrometry are enabling analysis of micro samples and unknown components that were not observable before. As the volume of information acquired from mass spectrometry increases, researchers are calling for simple techniques to analyze numerous components observed, and as a result, there is a rise in demand for comprehensive analytical techniques including multiple classification analysis. In this work, we will introduce a new technique of non-targeted analysis, which combines comprehensive analysis using high resolution GC-MS and unknown component analysis using soft ionization and EI.
Experimental
Table 1 shows the measurement conditions. Four different types of commercial coffee (A: Indonesian; B: Ethiopian; C: Guatemalan; D: Brazilian) were selected as samples. Each sample was measured 5 times (n=5). The samples were prepared as follows:
1) One gram of coffee beans was loaded into a 22 mL headspace (HS) vial, 15 mL of 100˚C water was added, and then the vial was sealed.
2) After the sample had cooled to room temperature, 10 mL of the supernatant was loaded into another HS vial, and 2 µL of an internal reference (p-Bromofluorobenzene) was added to the sample.
3) Finally, 2 mL of the above solution was sealed in a vial and used as a sample