Evaluation location: Illinois, United States
Fatty acid percentages of oil in seeds were determined by GC after converting the fatty acids to methyl esters. 50 seeds per accession were ground in 5 mL of 0.25 M sodium methoxide solution in 20 mL scintillation vials with a Finemech homogenizer for 1 min or until no whole seeds were present. Vials were sealed with aluminum lined screw caps and placed in a 60oC aluminum heating block for 30 min. After removing the vials from the block, 5 mL each of hexane and saturated sodium chloride were added and the contents thoroughly mixed. After the layers separated, 0.5mL aliquots from the top hexane layers were placed into 2 mL GC target vials, diluted to 2 mL with hexane and sealed with crimp caps. The vials were placed in the GC autosampler and injected onto the capillary column of a Hewlett Packard 5890 Series II gas chromatograph (GC) equipped with a flame-ionization detector and a 7963 autosampler/injector. GC separations were obtained on a SP-2380 30m X 0.25mm i.d. poly (90% biscyanopropyl/10% cyanopropylphenyl siloxane) Supelco capillary column. GC conditions were: 7C/min temperature ramp from 180C to 210C, followed by a 30C/min ramp to 265C and a 3min hold at 265C. Injector temperature was set to 265C, the flame ionization detector was heated to 250C, Helium flow through the column was 1 mL per min, the split ratio was 100:1 and the septum purge was 4 mL per min. A standard GLC mix of saturated and unsaturated fatty acid methyl esters (Nu-Check Prep) was used to identify retention times