Hp 5890 gc system

Fatty acid methyl esters were analyzed by GC using a HP 5890 GC System (Agilent, Santa Clara, CA, USA) equipped with a flame-ionization detector. The chromatography utilized an Omegawax capillary column (L × I.D. 30 m × 0.25 mm; Sigma-Aldrich). Fatty acids were identified by matching their GC retention time with those in a PUFA standard (Nu-Chek-Prep) and further analyzed using GC ChemStation Software (Agilent). The concentration of fatty acids was calculated using the internal standard curve in relation to the weighed-in quantity. Standard curves of the assayed fatty acids are provided in the supplements (Figure S1).

Fatty acid profiles of mouse diets and tail tissues (n = 9–10 per group) were analyzed by GC as described previously^{16 (link),55 (link)}. Briefly, tissue or food samples were ground to powder under liquid nitrogen and subjected to total lipid extraction and fatty acid methylation by 14% boron trifluoride (BF3)-methanol reagent (Sigma-Aldrich) at 100°C for 1 h. Fatty acid methyl esters were analyzed using a fully automated HP5890 GC system equipped with a flame-ionization detector (Agilent Technologies, Palo Alto, CA). The fatty acid peaks were identified by comparing their relative retention times with the commercial mixed standards (NuChek Prep, Elysian, MN), and area percentage for all resolved peaks was analyzed by using a Perkin-Elmer M1 integrator.