Simple and sensitive analysis of long-chain free fatty acids in milk by fluorogenic derivatization and high-performance liquid chromatography.
A highly sensitive high-performance liquid chromatography (HPLC) method is described for the simultaneous determination of some important saturated and unsaturated fatty acids in milk, including lauric (dodecanoic), myristic (tetradecanoic), palmitic (hexadecanoic), stearic (octadecanoic), palmitoleic (hexadecenoic), oleic (octadecenoic), and linoleic acids (octadecadienoic acids). The fatty acids were fluorogenically derivatized with 2-(2-naphthoxy)ethyl 2-(piperidino)ethanesulfonate (NOEPES) as their naphthoxyethyl derivatives. The resulting derivatives were separated by isocratic HPLC and monitored with a fluorometric detector (lambdaex = 235 nm, lambdaem = 350 nm). The fatty acids in milk were extracted with toluene, and the extract with the fatty acids was directly derivatized with NOEPES without solvent replacement. Determination of long-chain free fatty acids in milk is feasible by a standard addition method. A small amount of milk product, 10 microL, is sufficient for the analysis.
Lu
Chi-Yu
CY
Graduate Institute of Pharmaceutical Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan 807.
Wu
Hsin-Lung
HL
Chen
Su-Hwei
SH
Kou
Hwang-Shang
HS
Wu
Shou-Mei
SM
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005230:Fatty Acids, Nonesterified / Q000032:analysis*; D005470:Fluorometry / Q000379:methods; D008892:Milk / Q000737:chemistry*; D012680:Sensitivity and Specificity
D005230:Fatty Acids, Nonesterified