ICP OES determination of contaminant elements leached from food packaging films

Abstract

Determination of potential contaminants elements in food packing films arising from contact with acidic aqueous foods was undertaken by inductively coupled plasma optical emission spectrometry (ICP OES) in accordance with DIN EN 1186-1. Test sections from plastic films were totally immersed in 3% w/v CH3COOH used as the food simulant. Testing was conducted under three conditions: (1) 10 days at 40 °C; (2) 30 min at 70 °C and 10 days at 40 °C; and (3) 30 min at 100 °C and 10 days at 40 °C. These time and temperature conditions were considered to be the most severe situations likely to be encountered in practice. Several different containers were investigated, including a borosilicate glass beaker, a glass bottle used for food canning, as well as one of polystyrene. The glass bottle was selected for testing treatments according to procedure (3) and a polystyrene one was chosen for use with procedures (1) and (2). Limits of quantitation were adequate for the determination of Ag, B, Ba, Cd, Cr, Cu, Pb, Sb, Sn and Zn by solution nebulization ICP OES and As by chemical vapor generation (CVG-ICP OES). Results for the analysis of AccuStandard certified reference materials as well as spike recoveries show good agreement with expected concentrations, demonstrating the accuracy and precision of the determinations. Eleven samples of food packing material were analyzed. The lead was present in the range 4.8 - 85.3 μg L-1 in 10 of 11 evaluated packing material, showing the importance of quality control measures.