International. In a new study, German scientists investigated the coatings used on food cans about their potential to release nanomaterials (pigments, fillers) when food is stored and processed (sterilized) inside coated cans.
Two inner lacquers based on epoxy and polyester resins (with and without bisphenol A) and two seam cover coatings were used as lacquer matrices covering typical lacquer formulations. Eight different nanomaterials (four pigments and four fillers) that are typically used to adjust color and improve the thermal and mechanical stability of coatings were investigated. The aqueous solution of sodium dodecyl sulfate surfactant showed the best ability to disperse the nanomaterials with sufficient stability.
A stable multi-nanomaterial scattering, containing all eight nanomaterials in the same concentration each, was successfully used to develop an analytical method based on asymmetric field flow fractionation flow (AF4) coupled with multiangular laser light scattering detection (MALLS) and inductively coupled with plasma mass spectrometry (ICP-MS) that allowed screening of possibly migratory nanomaterials at a detection limit of 0.5 mg/0.5 mg/ dm2.
The coated metal plates were brought into contact with the aqueous solution of surfactants as an alternative food simulant for 2 ha 130ºC (sterilization) followed for 10 days at 60ºC (long-term storage). Using AF4/MALLS measurements, the release of small oligomeric components from internal coating formulations was detected. However, the particle and element specific detection system demonstrated the non-migration of nanomaterials (fillers or pigments) from all test samples.
Source: www.sciencedirect.com
