Isooctane

Pepsin from porcine gastric mucosa, porcine bile extract and pancreatin and lipase from porcine pancreas were obtained from Sigma (St. Louis, MO, USA). Gastric lipase (rabbit gastric extract, RGE 15) was obtained from Lipolytech^® (Marseille, France). The protocols described in Brodkorb et al. [28 (link)] were applied to determine the enzyme activities. Dichloromethane, chloroform, hexane, methanol, isooctane, isopropanol, dimethylformamide and acetonitrile, which were all HPLC grade, were purchased from Labscan (Dublin, Ireland). The purified water was obtained from a Milli-Q water purification system (Millipore, Milford, MA, USA). Sodium sulphate anhydrous, sodium chloride, potassium chloride and sodium carbonate were obtained from Panreac (Barcelona, Spain). Sodium methoxide (95%), sodium citrate dehydrate, formic acid (98%), triethylamine (99.5%), acetic acid and trinanoin were supplied by Sigma-Aldrich (St. Louis, MO, USA).

Commercial BM powder was kindly donated by Reny-Picot (Asturias, Spain). The sample was kept frozen at −35 °C until the analysis.
All solvents were at least HPLC grade and MS grade when available. Chloroform, hexane, methanol, isooctane, isopropanol, ammonium hydroxide, arsenic formate, and acetonitrile were purchased from LABSCAN (Dublin, Ireland). methanol (F.C.C.) ADITIO for industrial food use, sea sand, potassium hydroxide, and sodium carbonate were from PANREAC (Barcelona, Spain). Formic acid (98%) and triethylamine (99.5%), the TAG standards trinanoin and tridecanoin, the FFA standards pelargonic (C9), tridecanoic (C13), myristic (C14), palmitic (C16), estearic (C18), arachidonic (AA, 20:4), eicosapentaenoic (EPA, 20:5), and docosahexaenoic (DHA, 22:6) acids, the sterols 5α-cholestane, cholesterol (CHOL), cholesterol ester (CE), desmosterol, campesterol, β-sitosterol and lanosterol, monostearin, diolein and tripalmitin, as well as PI, PS, PE, SM, PC, and N-oleoylethanolamine standards were from Sigma-Aldrich (St. Louis, MO, USA). Reference samples with known composition as butter fat BCR-164 and BCR-519 (EU Com 121 missions; Brussels, Belgium) were from Fedelco Inc. (Madrid, Spain).