Rxi 17sil ms column

Aroma constituents were analyzed using a Pegasus 4D GC×GC-TOF mass spectrometer (LECO Corp., St. Joseph, MI, USA). The first dimension (1-D) was a non-polar Rxi-5MS column (30 m × 250 μm × 0.25 μm) (Restek Corp., Bellefonte, PA, USA) and the second (2-D) was a moderate polar Rxi-17Sil MS column (1.9 m × 100 μm × 0.1 μm) (Restek Corp.) The GC-O analysis was conducted using a 7890B-5977B GC-MS system (Agilent Technologies Inc., Santa Clara, CA, USA) equipped with an ODP-3 Olfactory Detection Port (Gerstel GmbH & Co. KG, Mülheim an der Ruhr, Germany).

Analysis was conducted in electron
ionization mode using a GC×GC/ToF-MS Pegasus 4D (LECO, St. Joseph,
MI) equipped with an Agilent 7890B gas chromatograph (Palo Alto, CA).
The columns used were the DB-1 MS UI (25 m × 0.25 mm × 0.25
μm; Agilent Technologies) and Rxi-17 Sil MS column (1.2 m ×
0.25 mm × 0.25 μm; Restek) in the first and second dimension,
respectively (Table S3).

One μg of purified LaCAO was added to 400 µl of 500 µM diamine in 50 mM Tris–HCl (pH 8) in a glass vial and incubated overnight at room temperature. The next morning, 10 µl of 10% KCN_(aq) were added, and the mixture was incubated at room temperature for 90 min. Following extraction with 150 µl of ethyl acetate, the organic layer was separated and dried over anhydrous Na₂SO₄. Assuming a quantitative yield of nitrile from the diamine, 1 Eq of acetic anhydride was added and the reaction was incubated at room temperature for 10 h before GC-MS analysis. As a positive control, the diamine was substituted with 500 µM 2-cyanopiperidine (Aldrich). As a negative control, heat-inactivated LaCAO was used.
The GC-MS analysis was performed on a Shimadzu GCMS-QP2010 system equipped with an EI (electron ionization) source. Separations were performed on an Rxi-17Sil MS column from Restek (20 m×0.18 mm×0.18 µm) using H₂ as carrier gas at a constant linear velocity of 50 cm s^–1. A 1 µl aliquot of sample was injected in splitless mode at 250 °C. The initial temperature of the oven was set at 50 °C and held for 1 min. Afterwards the temperature was ramped to 280 °C at a rate of 30 °C min^–1 and was maintained at 280 °C for 3 min (total run time=11.66 min). MS data acquisition was done using an electron energy of 70 eV in full scan mode (35–500 m/z) with a scan interval of 0.15 s.