Tetrapropylammonium bromide

For the preparation of the mesoporous materials, USY Zeolite (CBV780) was supplied by Zeolyst, with a nominal Si/Al ratio of 40, and tetrapropylammonium bromide 98% was purchased from Sigma-Aldrich (St. Louis, MO). Sodium hydroxide (98% pellets) was supplied by Fluka.
For the synthesis of the quaternary ammonium bromide surfactant with the tripropyl head, tri-n-propylamine and 1-bromohexadecane both from Sigma-Aldrich were employed.
For the catalytic evaluation, 1,3,5-triisopropylbenzene (C₁₅H₂₄, 95%, Sigma-Aldrich) was used as feed stock. The chemicals used for GC calibration are:

From Sigma-Aldrich: Benzene (C₆H₆, ≥ 99.8%), toluene (C₆H₅CH₃, ≥ 99.5%), para-xylene (C₆H₄(CH₃)₂, ≥99.5% GC), ortho-xylene (C₆H₄(CH₃)₂, ≥99.5% GC), meta-xylene (C₆H₄(CH₃)₂, ≥99.5% GC), 1,2,3-trimethylbenzene (C₆H₃(CH₃)₃, ≥99.5%, neat, GC), 1,2,4-trimethylbenzene (C₆H₃(CH₃)₃, 98%) and, 1,3-diisopropylbenzene (C₁₂H₁₈, 96%).

From Alfa Aesar: cumene (C₉H₁₂, 99%) and, 1,4-diisopropylbenzene (C₁₂H₁₈, 99%).

C. cardunculus L. leaves were collected during the flowering stage, in June 2015 in an experimental field (37°59′14.25″ N, 7°55′59.64″ W) and supplied in the dry form with a granulometry between 40–60 mesh. A cynaropicrin standard was commercially purchased from Extrasynthese (Lyon, France), with a purity ≥97.5 wt %. The compounds used in the formation of the DES, composed of quaternary ammonium salts as HBA and carboxylic acids as HBD, are the following: decanoic acid (purity of 99% purity) and choline chloride ([Ch]Cl, purity of 99%), both from Acros Organics (Geel, Belgium), hexanoic acid (purity of 99%) and myristic acid (purity of 98%), both from Fluka (Sintra, Portugal), 12-hydroxystearic acid (purity of 95%) supplied by Alfa Aesar (Karlsruhe, Germany), and tetraethylammonium chloride ([N₂₂₂₂]Cl), tetrabutylammonium chloride ([N₄₄₄₄]Cl), tetrapropylammonium chloride ([N₃₃₃₃]Cl), tetrapropylammonium bromide ([N₃₃₃₃]Br), and tetrabutylammonium bromide ([N₄₄₄₄]Br), all with a purity of 98% and purchased from Sigma-Aldrich (Sintra, Portugal). Common organic solvents were also tested as extraction media, namely acetone and dichloromethane with a purity of ≥99.99%, and n-hexane with a purity of 95%, all acquired from Sigma-Aldrich (Sintra, Portugal).

For the synthesis of deep eutectic solvents and gas mixture preparations, reagents with high purity (purity ≥98%), i.e., choline chloride, tetrapropylammonium bromide, levulinic acid, lactic acid, phenol, benzene, ethylbenzene, toluene, and o-xylene, were purchased from Sigma-Aldrich (St. Louis, MO, USA). For the synthesis of adsorbents, commercial silica gel (particle size 7 µm) and methanol were purchased from POCH (Gliwice, Poland). Gases, i.e., nitrogen, hydrogen and air were with high purity N 5.0 or N 5.0 were purchased from Linde-Gas (Łódź, Poland).