4.7. GC-MS Determination of Lipids

The portion of 10.0 mg of the extracted sample was mixed with: 100 µL of methyl nonadecanoate solution in MTBE and 100 µL of TMSH. The solution was incubated at 80 °C for 30 min and 1 µL of the output mixture was subjected to GC-MS analysis. The GC-MS determination was performed with a liquid chromatograph coupled with a time-of-flight mass spectrometry detector (Pegasus 4D, LECO, St. Joseph, MI, USA).

Operating parameters were set up as follows: Stabilwax capillary column (fused silica) 20 m × 0.18 mm diameter, 0.18 µm film thickness, gradient temperature: 50–245°C at 4° min⁻¹, carrier gas—helium and flow rate: 1 mL min⁻¹. Identification of lipids was based on the comparison of their mass spectra with data available from commercial database (37 Component FAME Mix, Supelco, Saint Louis, MO, USA. Cat. No. {"type":"entrez-protein","attrs":{"text":"CRM47885","term_id":"1048595075","term_text":"CRM47885"}}CRM47885). The content of the individual components was expressed as a percentage of total extracted lipids. All samples were tested in triplicates.