A Hewlett−Packard (HP) model 6890 GC equipped with a 30 m ×
0.25 mm i.d. (df = 0.25 μm) DB-1 bonded-phase fused-silica capillary
column (J & W Scientific, Folsom, CA) and an FID was used for the
analysis of hexanal. The linear velocity of the helium carrier gas was 30
cm/s at a split ratio of 20:1. The injector and the detector
temperatures were 300 and 280 °C, respectively. The oven
temperature was programmed to increase from 40 to 180 °C at 4
°C/min and held for 10 min. The quantitative analysis of hexanal was
conducted with undecane as an internal standard.16