The migration and degradation of N‐(1,3‐dimethylbutyl)‐N′‐phenyl‐p‐phenylenediamine from rubber hoses in milk lines

Abstract

N‐(1,3‐dimethylbutyl)‐N′‐phenyl‐p‐phenylenediamine (6PPD), an anti‐ageing agent in rubber hoses used in milk lines, may migrate into the milk and cause safety issues. Thus its migration and degradation in simulants/milk were studied to explore the changing trends and final levels, by high‐performance liquid chromatography. The results showed that 6PPD continuously increased in 95% ethanol and degraded more easily in simulants with a high water content. The degradation may be attributed to the π‐conjugated system of 6PPD and smaller steric hindrance of degradation products. No migration was observed into milk after 10 min. This study provides a novel and effective approach to evaluating 6PPD trends and safety for the dairy industry.