Application of standard addition to eliminate conjugated linoleic acid and other interferences in the determination of total Trans fatty acids in selected food products by infrared spectroscopy

A novel and rapid (5 min) attenuated total reflection‐Fourier transform infrared (ATR‐FTIR) spectroscopic method AOCS Cd 14d‐99 for the determination of total isolated trans fatty afids, which absorb at 966 cm‐, was recently developed, collaboratively studied, and applied to food products containing 1–50% rans fat (as percentage of total fat). Attempts to apply the ATR‐FTIR method to biological matrices of low trans fat and/or low total fat content, and to dairy and other products were not satisfactory due to interfering IR absorptions in the trans region. One group of interfering compounds with absorption bands near 985 and 948 cm−1 was the cis/trans positional isomes of conjugated linoleic acid (CLA) found in dairy and meat products from ruminants at levels of