Extraction Method and Determination of Sudan I Present in Sunset Yellow FCF by Isocratic High-Performance Liquid Chromatography

A method to extract and analyze Sudan I present in Sunset Yellow FCF (SYF) products was developed and validated. The method included the simple extraction of Sudan I from the SYF product using water, acetonitrile, and ethyl acetate and high-performance liquid chromatography (HPLC) analysis with isocratic elution using acetonitrile:water (7:3) with a photodiode array detector at 485 nm. This method was found to remove most of the excess SYF colorant and other impurities before injection to the HPLC instrument, making it easy to maintain precision control in routine laboratory tests for Sudan I in the SYF colorant. The detection limit of Sudan I in SYF products was 0.2 μg/g. A survey conducted to determine Sudan I in 13 commercial SYF samples from Japanese manufacturers from 1970 to 2010 showed that the levels of Sudan I ranged from 0.3 to 1.9 μg/g in products manufactured from 1970 to 1996 and were below the limit of detection in products manufactured after 2005.