This application note describes a method for identifying essential oil components using EI/MS and mixed reagent CI/MS. This method can improve the qualitative identification of essential oil components.
This application note presents a strategy to improve the qualitative identification of essential oil components using Gas Chromatography/Mass Spectrometry (GC/MS). The method combines Electron Impact (EI) mass spectrometry with a commercially available flavor and fragrance library and a secondary confirmation technique using Chemical Ionization (CI) with a 50:50 mix of acetonitrile and d3-acetonitrile.
| Column | DB5 30m x 0.25 mm ID x 0.25um film |
|---|---|
| Injection Volume | 1 wL |
| Split Ratio | 20:1 |
| Carrier Gas Flow | 1 mL/min |
| Initial Temperature | 60°C |
| Final Temperature | 240°C |
| Ramp Rate | 3°C/min |
| MS AGC Target | 10,000 |
| Scan Range EI | 40-500u |
| Scan Range CI | 90-500u |
| Scan Rate | 1.0 sec/scan |
A 50:50 mix of acetonitrile and d3-acetonitrile is used as the chemical ionization reagent.
The essential oils are diluted 50:1 in hexane and then split 20:1 in the injector.
The Adams Flavor and Fragrance Library is recommended, as it contains retention time data to improve the search process.