Method validation for migration testing of metals from plastic food contact materials to support Thai export

Abstract

This research aimed to validate test method for specific migration of metals into 3% (w/v) acetic acid from plastics intended to come into contact with food according to EU regulations on plastic food contact materials. The test method was developed using inductively coupled plasma-optical emission spectrometry (ICP-OES) to analyze the quantity of nine metals, i.e., aluminium (Al), barium (Ba), cobalt (Co), copper (Cu), iron (Fe), lithium (Li), manganese (Mn), nickel (Ni), and zinc (Zn) The results showed that the linear ranges of Al, Ba, Cu, Fe, Li, Mn, and Zn were 0-1.0 mg/kg while Co and Ni were 0-0.5 mg/kg and 0-0.1 mg/kg, respectively. The limits of detection (LOD) of Al, Ba, Co, Cu, Fe, Li, Mn, Ni, and Zn were 0.027, 0.026, 0.014, 0.024, 0.025, 0.024, 0.035, 0.004 and 0.022 mg/kg, respectively. The limits of quantification (LOQ) of Al, Ba, Cu, Fe, Li, Mn, and Zn were 0.05 mg/kg while Co and Ni were 0.02 and 0.01 mg/kg, respectively. The accuracy and precision at LOQ concentrations were acceptable corresponding with satisfactory percentage recovery (% recovery) and relative standard deviation (% RSD) of all elements in ranges of between 97.0-103% and 1.57-7.73%, respectively.