Automatic determination of 5-hydroxymethylfurfural (5-HMF) by a flow injection method

An automated flow injection (FI) method for the determination of 5-hydroxymethylfurfural in foodstuffs without sample pre-treatment has been developed. The method is based on the Winkler reaction and makes use of only one reagent. It permits the analysis of foodstuffs or their colored extracts since it runs on reversed FI. The linear range was 5–40 ppm with a rsd at 95% of 3.6, and sample frequency 70 h−1. Presence of SO2 as interferent is bypassed adding 2% H2O2 previously. The procedure is applied to the analysis of spirits, wine, liquid caramel and dried plums, and agree with the values obtained with the reference method.