Quantitative LC-ESI-MS/MS metabolic profiling method for fatty acids and lipophilic metabolites in fermentation broths from beta-lactam antibiotics production.

In the present paper, we report on the development of a straightforward reversed-phase liquid chromatography-electrospray ionization-tandem mass spectrometry method for the determination of the most abundant fatty acids; alpha-tocopherol and cephalosporin P1 in fermentation broths. Using this method, fatty acids could be successfully determined in extracts of fermentation broths from penicillin and cephalosporin production without prior derivatization. Matrix effects were investigated in detail, and various kinds of calibrations (i.e., by use of neat standard solutions as well as by matrix-matched calibration employing standard addition each with and without internal standards) were comparatively assessed. The optimized and validated method was employed for the analysis of extracts of fermentation broths and nutrition media.