Stability of 30 Fatty Acids in Serum Stored at −20°C for up to 5 Years

To the Editor: Stability studies have shown that fatty acids in serum cholesteryl ester (CE),1 triglyceride (TG), and phospholipid (PL) fractions stored at −80 °C are stable for up to 10 years (1); but data on the stability of unfractionated serum fatty acids stored at −80 °C or −20 °C are lacking. Polyunsaturated fatty acids (PUFAs), which are highly sensitive to oxidative degradation, were decreased by 14%–46% in plasma CE, TG, and PL fractions stored for 3 years at −20 °C (2). Butylated hydroxytoluene (BHT) has been tested as an antioxidant to prevent fatty acid degradation. Fatty acids in …