Melamine migration from tableware

The migration of melamine from tableware to food simulants has been measured by an ambient mass spectrometry method using a high-resolution instrument for extra sensitivity. Melamine is used in the preparation of melamine-formaldehyde resins which are moulded into cups, plates and the like but residual melamine can migrate from the objects into foods. A risk assessment by the US FDA suggested that melamine might cause conditions such as kidney stones and kidney failure, and even death. Its release from tableware has been the subject of many recent EU Rapid Alert System for Food and Feed (RASFF) notifications and the current EU safetly limit for humans is set to 2.5 mg/kg.

Scientists in Italy have devised a new method for measuring melamine migration using desorption electrospray ionisation mass spectrometry (DESI MS) which allows the rapid analysis of samples with minimal sample preparation. Monica Mattarozzi and colleagues from the University of Parma described their method in Talanta. A total of 44 old and new melamine items were exposed to 3% acetic acid as a food simulant and the degree of migration was assessed by analysing the extracts.

No melamine migrated from the old items, some up to 20 years old, presumably because all of it had already been lost, said Mattarozzi. However, when new mugs, tea cups, tumblers, cereal bowls, soup bowls, plates and mixing bowls were tested, migration was observed from some items, with two releasing melamine higher than the legal limit. It is also important to remember that exposure will occur repeatedly as the items are used again and again.

The DESI MS method will help to keep track of tableware safety and "will be very useful for high-throughput analysis as required for quality control applications."