Bpx70 column

A volume of 50 µL of total lipid extract was evaporated and resolubilized in 500 µL toluen-methanol (1:1, v/v) for methylation. The methylation reaction was performed in the presence of 500 µL BF₃/methanol (14%) used as catalyzer, under N₂ atmosphere, by heating at 100 °C for 90 min. The reaction was stopped by fast cooling of the samples and the addition of K₂CO₃ (10% in water). Isooctane was further added to extract the methylated fatty acids—the upper organic phase; the extraction was performed 2 times. The samples were dried under N₂ and re-solubilized in isooctane for GC analysis.
GC was performed on an HP 6890 (Agilent Technologies) instrument equipped with a fused silica capillary BPX70 column (Trajan, SGE; 60 m × 0.25 mm). The carrier gas was hydrogen (1 mL/min). The temperatures of the flame ionization detector and the split/splitless injector were set at 250 and 230 °C, respectively. The oven temperature program was as follows: 50 °C for 2 min, followed by 20 °C/min up to 140 °C, and 2 °C/min up to 240 °C (for 5 min). The samples were injected in a splitless mode. Peak detection, integration and quantitative analyses were executed using MassHunter software (Agilent Technologies, Santa Clara, CA, USA).

Alcohol-insoluble residue (AIR) was prepared and subjected to methylation analysis for both neutral and acidic monosaccharide linkage composition using a previously described procedure^{62 (link)}. Monosaccharide linkage analysis was performed on a Hewlett-Packard 6890 Gas Chromatograph with a Hewlett-Packard 5973 Mass Spectrometer (Agilent) equipped with a BPX70 column (25 m × 0.22 m minner diameter, film = 0.25 μm, SGE).