ENCIMSKA SINTEZA BUTIL LAKTATA V NEKONVENCIONALNIH TOPILIH - Kuhar, Doroteja (D. Kuhar, 2014)
Encimska sinteza butil laktata je reakcija zaestrenja n-butanola in mlečne kisline. Reakcijo smo izvajali v superkritičnem trifluorometanu ob prisotnosti imobiliziranega encima. Na reakcijo lahko vplivamo s spremembo tlaka, temperature in z različnim masnim razmerjem med kotopilom n-heksanom in reaktanti. Namen diplomskega dela je bila izvedba encimske sinteze butil laktata v nekonvencionalnem topilu trifluorometanu in določitev optimalnih reakcijskih parametrov, kot so tlak, temperatura ter določitev količine dodanega kotopila n-heksana. Kot biokatalizator smo uporabili imobilizirano lipazo B iz Candida antartice. Produkte in reaktante smo analizirali s plinsko kromatografijo in tekočinsko kromatografijo visoke ločljivosti. Vsebnost vlage smo določili s Karl-Fischerjevo titracijsko metodo. Najvišjo presnovo mlečne kisline in posledično največ produkta (butil laktata) smo dosegli ob dodatku 11 % n-heksana pri 55 ◦C in tlaku 20 MPa. Enzymatic synthesis of butyl lactate is a reaction of esterification between n-butanol and lactic acid. The reaction was carried out in an nonconventional solvent trifluoromethane in the presence of immobilized enzyme. The reaction can be influenced by the change in pressure, temperature and various weight ratio between the co-solvent n-hexane and the reactants. The main purpose of the diploma was to perform the enzymatic synthesis of butyl lactate in nonconventional solvent trifluoromethane and to determine optimal reaction parameters like pressure, temperature and also to determine the amount of added co-solvent n-hexane. As a biocatalyst, the lipase B from Candida antartica was used. Products and reactants were analyzed by gas chromatography and high performance liquid chromatography. The moisture content was determined by Karl-Fischer titration method. The highest conversion of lactic acid and consecutively the highest production of butyl lactate were achieved at addition of 11 % n-hexane, at 55 ◦ C and 20 MPa.