The application of dispersive liquid–liquid microextraction in the analyses of the fatty acid profile in bovine milk in response to changes in body condition score

摘要

Highlights?A novel microextraction method for fatty acids in milk is proposed.?Relationship between fatty acid profile and body condition score is examined.?Palmitic acid can be used to determine optimum body condition score.AbstractDispersive liquid–liquid microextraction (DLLME) was used prior to gas chromatography flame ionization detection (GC-FID) for the extraction of five fatty acids from milk taken from cows with different body condition scores. Optimum extraction conditions were: 300?μL of chloroform (extraction solvent), and 1?mL methanol (dispersive solvent). The procedure was optimised using Design of Experiments (DoE). The analytes were separated on a GC capillary column containing a polyethylene glycol stationary phase (15?m?×?0.53?mm?×?1.2?μm). Enrichment factors were in the range of 8–15 and limit of detection (LOD) was 0.04?μg/mL. Calibration graphs showed good linearity with coefficients of determination higher than 0.994% and relative standard deviations lower than 7%. This metho