AOAC Method 2012.13: GC Analysis of Fatty Acids in Powdered Infant Formula on SP^®-2560

技术

gas chromatography (GC): suitable

试验参数

sample/matrix: weigh 168 mg powdered infant formula (approximately 50 mg of fat) into a 25 mL centrifuge tube; add 2 mL of water and mix to dissolve; (let sit for 15 minutes at room temperature; add 5 mL of internal standard (C11:0 FAME + C13:0 TAG, each at 2 mg/mL in methyl tert butyl ether))
extraction: 5 mL of 5% (w/v) methanolic sodium methoxide solution; close tube and vortex for 10 seconds; after 180 seconds (time starts when sodium methoxide is added) add 2 mL of hexane; (after 210 seconds add 10 ml of neutralization solution (10% disodium hydrogen citrate/15% sodium chloride in water); gently shake using vortex mixer; centrifuge mixture at 1750 rpm for 5 minutes)
eluate post-treatment: transfer 200 μL of supernatant into 10 mL flask and dilute to mark with hexane
column: SP-2560, 100 m x 0.25 mm I.D., 0.20 μm (24056)
oven: 60 °C (1 min), 15 °C/min to 165 °C (1 min), 2 °C/min to 225 °C (20 min)
inj. temp.: 250 °C
detector: FID, 250 °C
carrier gas: helium, 0.8 mL/min
injection: 1μL, 10:1 split
liner: 4 mm I.D., split/splitless type, wool packed single taper FocusLiner^™ design

应用

food and beverages