This application note describes two retention time locked methods and retention time databases that improve the analysis of fatty acid methyl esters. In the first method, fatty acid methyl esters are analyzed on a DB-Wax column using gas chromatography/flame ionization detector or gas chromatography/mass spectrometry. In the second method, a DB-23 column is used. Retention time and mass spectral libraries are available for both methods. Retention time locking allows easy peak identification, easy exchange of data between instruments (gas chromatography/flame ionization detector, gas chromatography/mass spectrometry, different labs), and avoids the need to modify the retention times in calibra- tion tables after column maintenance or column change.
This document presents two retention time locked methods for the analysis of fatty acid methyl esters (FAMEs), a key application in food analysis. The first method utilizes an Agilent DB-Wax column for separating FAMEs based on carbon number and unsaturation, suitable for classical samples like vegetable oils and milk fat. The second method employs an Agilent DB-23 column with a cyanopropyl stationary phase to achieve higher resolution for complex mixtures, such as fish oils, and to separate cis/trans isomers.
| Column 1 | 30-m x 0.25-mm id x 0.25-ym DB-Wax |
|---|---|
| Column 2 | DB-23 column |
| Locking Compound | Methyl stearate |
| Locking Retention Time | 14.000 min |
| Instrument | Agilent 6890 GC |
Methyl stearate is used as the locking compound.
The retention time for methyl stearate is locked at 14.000 minutes.