Method provided in the national food safety standard GB 5413.36—2010 "Determination of trans fatty acids in foods & dairy products for infants and young children" was referred in this experiment, to determinate content of trans fatty acid in milk powder.
In the experiment, the fat in the milk powder were extracted with organic solvent, then the extracted fat were methyl-esterified under alkaline conditions to form methyl esters of fatty acids.  The fatty acid methyl esters formed were analyzed by a Gas Chromatograph equipped with a hydrogen flame ionization detector (FID) and quantified by external standard method.
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