Palladium on activated charcoal pd c

Lipase B from Candida antarctica immobilized on acrylic resin (activity measured to 11,000 PLU/g (propyl laurate units)) (CALB), deuterated chloroform (CDCl₃), dibutyl aluminum hydride (DIBAL-H) solution in toluene (25 wt %), and palladium on activated charcoal (Pd/C) were supplied by Sigma-Aldrich (Saint-Louis, MO, USA). Diethyl adipate (DEA), potassium iodine, methyl 4-chlorobutyrate, and diphenyl ether were purchased from Acros Organics (Geel, Belgium). 1,4-butanediol (1,4-BDO), acetophenone, ferulic acid, and methyl chloroacetate were supplied by Alfa Aesar (Heysham, UK). Methanol and potassium carbonate were supplied by Fisher scientific (Illkirch-Graffenstaden, France). Chloroform was supplied by Carlo Erba (Emmendingen, Germany). CALB was dried at 25 °C for 24 h under vacuum before use. Other reactants were employed without further purification.

High-performance liquid chromatography (HPLC) was used to measure the following: maltose, glucose, lactic acid, glycerol, acetic acid, and ethanol in the mash; a pre-fermentation evaluation; and in the distiller’s beer, a post-fermentation evaluation. A 25 mL sample per batch was taken after mashing, and another 25 mL sample was taken after fermentation; the samples were kept at −20 °C. For HPLC evaluation, “mash” and “beer” samples were centrifuged at 4000× g with an Eppendorf 5810R centrifuge (Hamburg, Germany). They were filtered to avoid any solids transferring into the HPLC vial. A final solution was made of 1.2 mL containing 1.14 mL of each mash or beer sample and 0.06 mL of DI water. The HPLC procedure was described by Sluiter [22 ] and adapted by Dodge [23 (link)]. Following the two-stage acid hydrolysis, the amounts of glucose and maltose, lactic acid, acetic acid, glycerol, and ethanol were measured using a Dionex UltiMate 3000 HPLC instrument (Dionex Corporation, Sunnyvale, CA, USA) equipped with a refractive index detector and a Biorad Aminex HPX-87H column, using 5 mM H₂SO₄ as the mobile phase at a flow rate of 0.4 mL/min and a column temperature of 50 °C (Hercules, CA, USA). The organic solvents, hexane, petroleum ether, chloroform, ethyl acetate, IPA, and palladium on activated charcoal (Pd/C), were purchased from Sigma-Aldrich, St. Louis, MO, USA.