Approximately 10g of liquid sample (sample A, B, C, D, E, F, G, H, I and J) were placed in 40mL clear vials and limonene was extracted using SBSE, or Twister, at room temperature for 90min. Twisters were heated to 280oC for 3 minutes inside a thermal desorption unit (TDU). The TDU transfer temp was 280oC and operated in splitless mode with purge time 1.00min. The target volatile generated during thermal desorption of Twister bar were swept onto a cryo-cooled (LN2) inlet liner at -90oC (CIS4 liner in split mode 20:1). The liner contained glass beads for increased adsorption. The liner was heated to 280oC for 3min and volatiles were transferred to the analytical DB-5 MACH column. Column heating conditions were: initial temp. at 35oC for 5 min then 10oC/min to 135oC for 0min, and the second ramp rate 100oC/min to final temp. at 250oC for 3min. Total ion chromatogram time was 19.15min. Conditions were ramped pressure with initial pressure 6.80 psi for 5 min then 0.57 psi/min to 12.50 psi, the second ramp pressure 5.74 psi/min to 19.10 psi for 3 min. MSD transfer line temperature 280oC. Scan parameters were 35-350a.m.u. The DB-5 capillary column utilized was a 30m x 0.25mm I.D. x 0.25µm film thickness. The component were extracted by m/z 136 and identified by matching spectra with a Wiley 2007 library.
Data analysis was conducted by integrating total ion chromatograms with Agilent ChemStation and copying selected peak areas to an Excel spreadsheet.