Microextraction method of medium and long chain fatty acids from milk.

The aim of this research was to develop a method for microextraction and quantification of long and medium chain fatty acids from milk. The proposed method was carried out on three steps: (1) lipids extraction from 10 μL of whole or skimmed milk containing omega-3 fatty acids (FAs) during 12, 24, 48, 72 and 96 h, in 2 mL chloroform: methanol mixture (2:1); (2) acid methylation of FAs; and (3) quantification of FAs methyl esters by gas chromatography. Using this method, the percentage recovery of FAs was higher (67% for whole and 85% for skimmed milk) compared with AOAC method 905.02 recovery (49% and 83%, respectively). Good reproducibility and repeatability (<3%) were obtained. The method developed can be useful for researching and in routine quality control. Additionally, it is simpler, faster and cheaper than the reference procedure since it requires minimum sample and solvents volume as well as fewer steps.