ICP-AES Determination of TiO2 in Plastic Packing Materials for Food with Microwave Assisted Sample Digestion

ICP-AES was applied to the determination of TiO2 in plastic food packing materials. One hundred mg of sample was homogenized and digested with mixed solution containing 4 mL of con. HNO3 and 3 mL of con. H2SO4. Wavelength of 336.122 nm was selected as analytical spectral line for determination of Ti in sample solution. Linear relationship between values of analytical signal and mass concentration of titanium was kept in the range within 25 mg·L-1, with detection limit (3S/N) of 4.0 mg·kg-1. Values of recovery obtained by standard addition method were in the range of 93.6%-101.2%. Test for precision was made and RSD′s (n=8) found were less than 1%.