G005824

GC Analysis of FAMEs in Walnuts on SP^®-2560

suitable for GC

Properties

• technique(s): gas chromatography (GC): suitable
• test parameters: 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
• application(s): agriculture; food and beverages

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.

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