Polyamide Research Papers - Academia.edu (original) (raw)

Food contact materials include both packaging materials and utensils, plates, containers, processing machines, etc. The use of plastic utensils for cooking and frying (spatulas, stirrers, utensils for overturning food, ladles, slotted spoons or having other forms) has increased in recent years, as these items are inexpensive and unbreakable, available widely in the market, relatively resistant to high temperatures and do not scratch the surface of the dishes. Most of them are made of different types of nylon, known under the chemical name Polyamide (PA). If the monomer ratio is well balanced, and the reaction of the chemical synthesis is completed, all the monomers are incorporated into the polymer structure. When the balance between monomers is inappropriate, however, free monomers or socyanates remain and can migrate to food and to form primary aromatic amines (PAA). PAA can end up in food as residual monomers from food contact materials, as hydrolysis products of isocyanates or as contaminants from azo dyes. They may be formed chemically in food or to migrate to it from food contact materials if they are not produced in compliance with good manufacturing practice.
The primary aromatic amines are a family of compounds, some of which are classified by the International Agency for Research on Cancer as «possibly carcinogenic to humans» and their presence in food should be avoided.
In recent years, there was anxiety in the EU member states concerning received data for migration of primary aromatic amines from polyamide kitchenware imported from third countries. Regulation (EU) № 284/2011 lays down specific conditions and detailed procedures for the import of those articles and establishes maximum residue limits for specific migration of PAA. This article published a validated screening spectrometric method for the determination of total primary aromatic amines represented as aniline equivalent, which satisfies the requirements of Regulation 284/2011. The method is based on the diazotization of primary aromatic amines with sodium nitrite in acidic medium and subsequent neutralization of residual nitrosating agent with ammonium sulfamate. Nitro derivatives were coupled with N- (1-naphthyl) ethylenediamine dihydrochloride to yield violet colored complex, which was then concentrated by solid phase extraction. The measured absorbance at a wavelength of 550 nm is proportional to the total content of primary aromatic amines, expressed as aniline equivalents. The limit of detection LOD is 0.001 mg/kg, expressed as aniline; the limit of quantification LOQ is 0.002 mg/kg, expressed as aniline; the working range of the method is between 0.002 and 0.04 mg/kg, expressed as aniline.
This method is applied for exploring the migration of primary aromatic amines from polyamide kitchen utensils available on the Bulgarian market. The obtained data do not show a potential risk for consumers from the migration of these substances from polyamide articles when the items are labeled with information about the origin, type of material, conditions of use and are used according to the label instructions. Items without marking and labeling, as well as those labeled with a non-useful information, for example, „made from harmless plastic” are not the subject of this study. the wide spread of such items requires caution regarding their safety for consumers.