Abstract
There is a need to determine the tissue burdens of inhaled titanium dioxide due to the widespread industrial use of this compound. A high-throughput method for the determination of TiO2 as titanium in rodent lung and lung-associated lymph node tissues by inductively coupled plasma optical emission spectrometry (ICP-OES) was developed and validated. Samples were digested in open-vessel, disposable centrifuge tubes in the presence of nitric and hydrofluoric acids. The determined method quantitation limit (MQL) was 4.2 µg TiO2/g tissue. Replicate control samples prepared at this level were determined with a high level of accuracy (100%) and precision (2% RSD). After validation, the described method was applied to determine the concentration of TiO2 (as titanium) in 600 rodent tissue samples spanning a 16-month time period. During this time period, laboratory control samples (n = 48) were analyzed to assess the long-term precision and accuracy of the method. The average recovery of titanium in these samples was 102±4.8%.
Acknowledgment
The authors would like to thank the CIIT Centers for Health Research for their support of this effort by providing resources from the TiO2 panel of the American Chemistry Council and the European Chemical Industry Council. The authors also acknowledge Dr. Barbara Kuyper for her editorial assistance in the preparation of this manuscript.