GC Analysis of FAMEs in Walnuts on SP®-2560
CONDITIONS
column
SP-2560, 100 m x 0.25 mm I.D., 0.20 μm (24056)
oven
180 °C
inj. temp.
250 °C
detector
FID, 250 °C
carrier gas
helium, 1 mL/min
injection
1 μL, split 100:1
liner
4 mm ID FocusLiner w/taper
sample
ground walnuts prepared for analysis per AOCS Official Method Ce 1k-09
Description
Analysis Note
This application illustrates the extraction and GC analysis of walnuts for fatty acids. Walnut is considered a significant plant source of alpha-linolenic acid (ALA). Both ALA and linoleic acid (LA) are the predominant essential fatty acids in humans (1). The samples were prepared using acid digestion /alkali hydrolysis followed by methylation as described in AOCS Official Method Ce 1k-09 (2). BHT was added as an antioxidant prior to extraction. All samples were concentrated to 1 mL prior to GC analysis.
The FAME composition of vegetable oils is normally determined using AOCS Method Ce 1h-05, which designates the use of the a cyanopropylsilicone column (3). The SP-2560 column is specifically mentioned in the method. The use of a highly polar column enables simultaneous determination of trans isomers of unsaturated fatty acids along with saturated and cis-unsaturated.
Legal Information
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