Determination of Titanium Dioxide in Minced Products by ICP-MS

Sample of minced products (0.500 0 g) was digested in the mixture of 5 mL HNO₃ and 1 mL HF using microwave, with heating at the temperature of 200℃ for 20 min, and then the solution was cooled to room temperature, and made its volume up to 25.0 mL. The content of titanium dioxide in above solution was determined by inductively coupled plasma mass spectrometry (ICP-MS). As shown by the results, linear relationship of Ti was found in the range of 10-200 μg·L^-1, with detection limit (3s) of 0.06 mg·kg^-1. Tests for recovery was made by standard addition method, giving results in the range of 88.0%-93.2%. Values of RSDs (n=6) were in the range of 1.0%-3.7%. 42 batches of raw materials and 100 batches of minced products were analyzed by the proposed method, and average contents of titanium dioxide were found about 2.5 mg·kg^-1 and 5.0 mg·kg^-1 respectively. The contents of titanium dioxide in 10% of minced products were higher than 100 mg·kg^-1, and there was a risk of exceeding the range of use of titanium dioxide.