3 g crushed potato chips in 15 mL vial
DVB/Carboxen/PDMS, 50/30 μm, StableFlex (57328-U)
headspace, 65 °C, 20 min, with stirring
3 min, 250 °C
SPB-1 SULFUR, 30 m × 0.32 mm I.D., 4.0 μm (24158)
250 °C
45 °C (1.5 min) to 250 °C at 12 °C/min, hold 10 min
quadrupole mass spectrometer, m/z = 35-290 at 0.6 sec/scan
helium, 40 cm/sec
Splitless/split, closed 2 min
0.75 mm liner
3g crushed potato chips in 15 mL vial
Potato chips can contain up to 50% oil and are subject to rancidity. Aldehydes, particularly hexanal and heptanal, are formed from fatty acids that are cleaved at the double bonds when exposed to ultraviolet light and air. A package of 3-year-old potato chips was analyzed using SPME and compared to a fresh package. The presence of aldehydes indicated that the older chips were rancid. However, due to the age of the chips, further oxidation of the aldehydes occurred that resulted in the formation of hexanoic and heptanoic acids. A Carboxen/PDMS/DVB fiber was inserted into the headspace of the potato chip samples at 65 °C for 20 minutes with agitation. The fiber was then analyzed using GC/MS on a SPB-1 SULFUR column. This non-polar column has a thick film and is ideal for smaller molecules.
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