[Methodical aspects of hygienic safety assessment of polymeric materials in contact with foodstuffs].

It was purposed new technique by capillary gas chromatography (GC) for the low level determination of monomer hexamethylenediamine (HMDA) in food simulants water from polymeric materials in contact with foodstuffs. Hexamethylenediamine, HN2-(CH2)6-NH2, is a monomer used in the manufacture of certain of polyamide plastic materials and articles intended to come into contact with foodstuffs. Compound exhibits all the chemical properties of aliphatic amines, is an irritant, causing dermatitis, can accumulate in the body, the degree of human exposure to HMDA assigned to the 2nd class of hazard - the substance is highly dangerous. There was studied two methodological approaches pre-derivatization of compound for GC determination. The first approach involves conversion of the free diamine using ethyl chloroformate as derivatizing agent followed by analysis of the resulting diurethan by gas chromatography using a flame ionization and mass selective detection (HMDA was quantitated by selective ion monitoring at m/z 102, the lower detection limit of 1 ng). According to second methodological approach the water samples were mixed with sodium chloride and extracted with toluene, then derivatized with trifluoroacetic anhydride (60 min, 55 degrees C) to diamide, 1 M potassium phosphate buffer (pH 7,0) was add to remove excess derivatizing agent, followed by analysis of resulting diamide by gas chromatography with electron capture detection (lower limit value 0,01 ng). Conformation of HMDA levels is carried out by combined gas chromatography/mass spectrometry (HMDA was quantitated by selective ion monitoring at m/z 126, the lower limit value of 0,1 ng). The optimal pre-derivatization of the second approach for the determination of low levels of HMDA in the water extracts. The range of measured concentrations of 0,005-0,5 mg/dm3, recovery 88-101%, the total error of measurement is 16%, the relative standard deviation is 1,85%. The method was tested in the study of aqueous extracts of the 10 random samples intended for food purchased in the consumer market. Shows the corresponding output level hexamethylenediamine requirements for products of this type.