DETECTION OF TOTAL TRANS-FATTY-ACIDS CONTENT IN MARGARINE - AN INTERCOMPARISON STUDY OF GLC,GLC-IR, AND OPTOTHERMAL WINDOW (OPEN PHOTOACOUSTIC CELL)(TLC,FT)

Four techniques, i.e., gas-liquid chromatography, gas-liquid chromatog raphy + thin-layer chromatography, and two spectroscopic methods, Four ier transform infrared spectroscopy and optothermal window, a variant of the open photoacoustic cell, were intercompared to determine their potential to detect the total trans fatty acid content in margarine, A t the same time, this study represents a first application of the opto thermal window technique at long wavelengths (10 mu m). The total tran s fatty acid data obtained by different methods show good mutual agree ment, Besides offering several attractive advantages above conventiona l methods, the optothermal window also proved suitable for measuring t otal trans fatty acid content as low as 2%.