Abstract: The objective of this study was to explore the migration pattern of the heavy metal lead from a ceramic food contact material into different acidic food simulants at different pH values and temperatures. Migration experiments were carried out by completely immersing the ceramic material in each tested food simulant. The amount of lead released into acetic acid, citric acid and lactic acid solutions was determined by inductively coupled plasma optical emission spectrometry, and its relationship with immersion time, and the temperature, pH and type of acidic food simulant was analyzed. Results showed that the release of lead from the ceramic material was positively with immersion time and temperature and that the average release rate accelerated with increasing temperature. The concentration of lead dissolved in 4% (V/V) acetic acid solution at 20 ℃ was 3.276?mg/L after immersion for 240 h as opposed to 52.413?mg/L at 70 ℃, and the average dissolution rate increased from 0.087? to 1.229? mg/(m2·h) with increasing temperature from 20 to 70 ℃. The dissolution of lead was negatively correlated with the pH of food simulant. The amount of lead dissolved in 4% (V/V) acetic acid solution at pH 2.43 and 20% (V/V) acetic acid solution at pH 1.93 at 20 ℃ was 1.876 and 2.412?mg/L after 24 h of contact with the ceramic material, respectively. Moreover, the dissolution of lead was related to the type of acidic food simulant. Under the same pH conditions, the acidic food simulant with hydroxyl groups dissolved more lead. To sum up, contact time, and the pH, temperature and type of acidic food simulant all affected the dissolution of lead from the ceramic material. The release of lead was linearly correlated with the square root of migration time during the early period and then was linearly correlated with migration time during the middle and late period. The relationship of lead release with the temperature obeyed the Arrhenius law, while the relationship with the pH of acidic food simulant conformed to a logarithmic function.

Key words: ceramic food contact materials; acidic food simulants; lead release pattern