THE CONTENT OF HEAVY-METALS IN FOOD-PACKAGING PAPER - AN ATOMIC-ABSORPTION SPECTROSCOPY INVESTIGATION

The levels of four representative heavy metals-Cd, Cr, Pb and Hg- have been measured by atomic absorption spectroscopy (AAS) in 12 different samples of paper: 7 different kinds of food packaging paper, commonly employed in Italy (brown and white bread bags, brown and white bakery paper, white bakery bag, butcher's paper and salami paper), and 5 sam ples of non-food paper (two newspapers, one weekly magazine, one blue and one yellow notebook), assayed, for comparative purposes, in the sa me experimental conditions. The levels of heavy metals have been measu red in all the samples according to two different procedures: i) after immersion in distilled water for 24 h at T = 23%; and ii) after immer sion in 3% v/v acetic acid for 24 h at T = 40 degrees C. The results o f the present investigation show that all samples of food packaging pa per contain concentrations of heavy metals that are generally lower th an those detected in samples of common paper. Moreover, our results sh ow that ther is a remarkable difference among the levels of heavy meta ls depending on the procedure of sample pretreatment. Our observation points out that the pretreatment usually indicated as 'migration test' (performed in 3% v/v acetic acid at T = 40 degrees C), being remarkab ly more drastic than the 'extraction test' (performed in distilled wat er at T = 23 degrees C), should be requested in all those cases in whi ch a direct contact occurs between the food and the paper packaging. ( C) 1997 Elsevier Science Ltd.