Fatty acid analysis of Arthrospira platensis

For fatty acid (FA) analysis, the A. platensis biomass was transmethylated with 2% H₂SO₄ in a methanol/toluene mixture (90:10, v/v) at 80 °C for 1.5 h. Heptadecanoic acid (C17:0) was added as an internal standard. Then, an analysis of fatty acid methyl esters (FAMEs) was carried out using a Shimadzu-2014C gas chromatograph, equipped with a flame ionization detector (Shimadzu, Kyoto, Japan) and fused silica capillary column DB-WAX (30 m × 0.25 mm). The injection port temperature was 260 °C. The column temperature was programmed from 190 °C (with a hold of 5 min) to 250 °C (with a hold of 5 min), at a rate of 5 °C min⁻¹. The amount of individual FAMEs was calculated according to the method described by Li et al. [32 (link)].